Mixed logit model of intended residential mobility in renovated historical blocks in China

NARCIS (Netherlands)

Jiang, W.; Timmermans, H.J.P.; Li, H.; Feng, T.

2016-01-01

Using data from 8 historical blocks in China, the influence of socialdemographic characteristics and residential satisfaction on intended residentialmobility is analysed. The results of a mixed logit model indicate that higher residential satisfaction will lead to a lower intention to move house,

Another Look at the Method of Y-Standardization in Logit and Probit Models

DEFF Research Database (Denmark)

Karlson, Kristian Bernt

2015-01-01

This paper takes another look at the derivation of the method of Y-standardization used in sociological analysis involving comparisons of coefficients across logit or probit models. It shows that the method can be derived under less restrictive assumptions than hitherto suggested. Rather than...

An integrated Markov decision process and nested logit consumer response model of air ticket pricing

NARCIS (Netherlands)

Lu, J.; Feng, T.; Timmermans, H.P.J.; Yang, Z.

2017-01-01

The paper attempts to propose an optimal air ticket pricing model during the booking horizon by taking into account passengers' purchasing behavior of air tickets. A Markov decision process incorporating a nested logit consumer response model is established to modeling the dynamic pricing process.

Analysis of Internet Usage Intensity in Iraq: An Ordered Logit Model

OpenAIRE

Almas Heshmati; Firas H. Al-Hammadany; Ashraf Bany-Mohammed

2013-01-01

Intensity of Internet use is significantly influenced by government policies, people’s levels of income, education, employment and general development and economic conditions. Iraq has very low Internet usage levels compared to the region and the world. This study uses an ordered logit model to analyse the intensity of Internet use in Iraq. The results showed that economic reasons (internet cost and income level) were key cause for low level usage intensity rates. About 68% of the population ...

Study on Emission Measurement of Vehicle on Road Based on Binomial Logit Model

OpenAIRE

Aly, Sumarni Hamid; Selintung, Mary; Ramli, Muhammad Isran; Sumi, Tomonori

2011-01-01

This research attempts to evaluate emission measurement of on road vehicle. In this regard, the research develops failure probability model of vehicle emission test for passenger car which utilize binomial logit model. The model focuses on failure of CO and HC emission test for gasoline cars category and Opacity emission test for diesel-fuel cars category as dependent variables, while vehicle age, engine size, brand and type of the cars as independent variables. In order to imp...

Ordered LOGIT Model approach for the determination of financial distress.

Science.gov (United States)

Kinay, B

2010-01-01

Nowadays, as a result of the global competition encountered, numerous companies come up against financial distresses. To predict and take proactive approaches for those problems is quite important. Thus, the prediction of crisis and financial distress is essential in terms of revealing the financial condition of companies. In this study, financial ratios relating to 156 industrial firms that are quoted in the Istanbul Stock Exchange are used and probabilities of financial distress are predicted by means of an ordered logit regression model. By means of Altman's Z Score, the dependent variable is composed by scaling the level of risk. Thus, a model that can compose an early warning system and predict financial distress is proposed.

Essays on pricing dynamics, price dispersion, and nested logit modelling

Science.gov (United States)

Verlinda, Jeremy Alan

The body of this dissertation comprises three standalone essays, presented in three respective chapters. Chapter One explores the possibility that local market power contributes to the asymmetric relationship observed between wholesale costs and retail prices in gasoline markets. I exploit an original data set of weekly gas station prices in Southern California from September 2002 to May 2003, and take advantage of highly detailed station and local market-level characteristics to determine the extent to which spatial differentiation influences price-response asymmetry. I find that brand identity, proximity to rival stations, bundling and advertising, operation type, and local market features and demographics each influence a station's predicted asymmetric relationship between prices and wholesale costs. Chapter Two extends the existing literature on the effect of market structure on price dispersion in airline fares by modeling the effect at the disaggregate ticket level. Whereas past studies rely on aggregate measures of price dispersion such as the Gini coefficient or the standard deviation of fares, this paper estimates the entire empirical distribution of airline fares and documents how the shape of the distribution is determined by market structure. Specifically, I find that monopoly markets favor a wider distribution of fares with more mass in the tails while duopoly and competitive markets exhibit a tighter fare distribution. These findings indicate that the dispersion of airline fares may result from the efforts of airlines to practice second-degree price discrimination. Chapter Three adopts a Bayesian approach to the problem of tree structure specification in nested logit modelling, which requires a heavy computational burden in calculating marginal likelihoods. I compare two different techniques for estimating marginal likelihoods: (1) the Laplace approximation, and (2) reversible jump MCMC. I apply the techniques to both a simulated and a travel mode

Logit and probit model in toll sensitivity analysis of Solo-Ngawi, Kartasura-Palang Joglo segment based on Willingness to Pay (WTP)

Science.gov (United States)

Handayani, Dewi; Cahyaning Putri, Hera; Mahmudah, AMH

2017-12-01

Solo-Ngawi toll road project is part of the mega project of the Trans Java toll road development initiated by the government and is still under construction until now. PT Solo Ngawi Jaya (SNJ) as the Solo-Ngawi toll management company needs to determine the toll fare that is in accordance with the business plan. The determination of appropriate toll rates will affect progress in regional economic sustainability and decrease the traffic congestion. These policy instruments is crucial for achieving environmentally sustainable transport. Therefore, the objective of this research is to find out how the toll fare sensitivity of Solo-Ngawi toll road based on Willingness To Pay (WTP). Primary data was obtained by distributing stated preference questionnaires to four wheeled vehicle users in Kartasura-Palang Joglo artery road segment. Further data obtained will be analysed with logit and probit model. Based on the analysis, it is found that the effect of fare change on the amount of WTP on the binomial logit model is more sensitive than the probit model on the same travel conditions. The range of tariff change against values of WTP on the binomial logit model is 20% greater than the range of values in the probit model . On the other hand, the probability results of the binomial logit model and the binary probit have no significant difference (less than 1%).

Associating Crash Avoidance Maneuvers with Driver Attributes and Accident Characteristics: A Mixed Logit Model Approach

DEFF Research Database (Denmark)

Kaplan, Sigal; Prato, Carlo Giacomo

2012-01-01

as from the key role of the ability of drivers to perform effective corrective maneuvers for the success of automated in-vehicle warning and driver assistance systems. The analysis is conducted by means of a mixed logit model that accommodates correlations across alternatives and heteroscedasticity. Data...

Valuing Non-market Benefits of Rehabilitation of Hydrologic Cycle Improvements in the Anyangcheon Watershed: Using Mixed Logit Models

Science.gov (United States)

Yoo, J.; Kong, K.

2010-12-01

This research the findings from a discrete-choice experiment designed to estimate the economic benefits associated with the Anyangcheon watershed improvements in Rep. of Korea. The Anyangcheon watershed has suffered from streamflow depletion and poor stream quality, which often negatively affect instream and near-stream ecologic integrity, as well as water supply. Such distortions in the hydrologic cycle mainly result from rapid increase of impermeable area due to urbanization, decreases of baseflow runoff due to groundwater pumping, and reduced precipitation inputs driven by climate forcing. As well, combined sewer overflows and increase of non-point source pollution from urban regions decrease water quality. The appeal of choice experiments (CE) in economic analysis is that it is based on random utility theory (McFadden, 1974; Ben-Akiva and Lerman, 1985). In contrast to contingent valuation method (CVM), which asks people to choose between a base case and a specific alternative, CE asks people to choice between cases that are described by attributes. The attributes of this study were selected from hydrologic vulnerability components that represent flood damage possibility, instreamflow depletion, water quality deterioration, form of the watershed and tax. Their levels were divided into three grades include status quo. Two grades represented the ideal conditions. These scenarios were constructed from a 35 orthogonal main effect design. This design resulted in twenty-seven choice sets. The design had nine different choice scenarios presented to each respondent. The most popular choice models in use are the conditional logit (CNL). This model provides closed-form choice probability calculation. The shortcoming of CNL comes from irrelevant alternatives (IIA). In this paper, the mixed logit (ML) is applied to allow the coefficient’s variation for random taste heterogeneity in the population. The mixed logit model(with normal distributions for the attributes) fit the

The importance of examining movements within the US health care system: sequential logit modeling

Directory of Open Access Journals (Sweden)

Lee Chioun

2010-09-01

Full Text Available Abstract Background Utilization of specialty care may not be a discrete, isolated behavior but rather, a behavior of sequential movements within the health care system. Although patients may often visit their primary care physician and receive a referral before utilizing specialty care, prior studies have underestimated the importance of accounting for these sequential movements. Methods The sample included 6,772 adults aged 18 years and older who participated in the 2001 Survey on Disparities in Quality of Care, sponsored by the Commonwealth Fund. A sequential logit model was used to account for movement in all stages of utilization: use of any health services (i.e., first stage, having a perceived need for specialty care (i.e., second stage, and utilization of specialty care (i.e., third stage. In the sequential logit model, all stages are nested within the previous stage. Results Gender, race/ethnicity, education and poor health had significant explanatory effects with regard to use of any health services and having a perceived need for specialty care, however racial/ethnic, gender, and educational disparities were not present in utilization of specialty care. After controlling for use of any health services and having a perceived need for specialty care, inability to pay for specialty care via income (AOR = 1.334, CI = 1.10 to 1.62 or health insurance (unstable insurance: AOR = 0.26, CI = 0.14 to 0.48; no insurance: AOR = 0.12, CI = 0.07 to 0.20 were significant barriers to utilization of specialty care. Conclusions Use of a sequential logit model to examine utilization of specialty care resulted in a detailed representation of utilization behaviors and patient characteristics that impact these behaviors at all stages within the health care system. After controlling for sequential movements within the health care system, the biggest barrier to utilizing specialty care is the inability to pay, while racial, gender, and educational disparities

An Empirical Analysis of Television Commercial Ratings in Alternative Competitive Environments Using Multinomial Logit Model

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Dilek ALTAŞ

2013-05-01

Full Text Available Watching the commercials depends on the choice of the viewer. Most of the television viewing takes place during “Prime-Time” unfortunately; many viewers opt to zap to other channels when commercials start. The television viewers’ demographic characteristics may indicate the likelihood of the zapping frequency. Analysis made by using Multinomial Logit Model indicates how effective the demographic variables are in the watching rate of the first minute of the television commercials.

Un procedimiento para selección de los modelos Logit Mixtos

OpenAIRE

Ruíz Gallegos, José de Jesús

2004-01-01

En el presente trabajo se hace una revisión de dos modelos que han tenido una fuerte aplicabilidad en los problemas de elecciones discretas: El modelo Logit y el modelo Logit Mixto. Además, se propone el uso del estadístico de Cox para seleccionar modelos, en el modelo Logit Mixto.

Airport Choice in Sao Paulo Metropolitan Area: An Application of the Conditional Logit Model

Science.gov (United States)

Moreno, Marcelo Baena; Muller, Carlos

2003-01-01

Using the conditional LOGIT model, this paper addresses the airport choice in the Sao Paulo Metropolitan Area. In this region, Guarulhos International Airport (GRU) and Congonhas Airport (CGH) compete for passengers flying to several domestic destinations. The airport choice is believed to be a result of the tradeoff passengers perform considering airport access characteristics, airline level of service characteristics and passenger experience with the analyzed airports. It was found that access time to the airports better explain the airport choice than access distance, whereas direct flight frequencies gives better explanation to the airport choice than the indirect (connections and stops) and total (direct plus indirect) flight frequencies. Out of 15 tested variables, passenger experience with the analyzed airports was the variable that best explained the airport choice in the region. Model specifications considering 1, 2 or 3 variables were tested. The model specification most adjusted to the observed data considered access time, direct flight frequencies in the travel period (morning or afternoon peak) and passenger experience with the analyzed airports. The influence of these variables was therefore analyzed across market segments according to departure airport and flight duration criteria. The choice of GRU (located neighboring Sao Paulo city) is not well explained by the rationality of access time economy and the increase of the supply of direct flight frequencies, while the choice of CGH (located inside Sao Paulo city) is. Access time was found to be more important to passengers flying shorter distances while direct flight frequencies in the travel period were more significant to those flying longer distances. Keywords: Airport choice, Multiple airport region, Conditional LOGIT model, Access time, Flight frequencies, Passenger experience with the analyzed airports, Transportation planning

Street Choice Logit Model for Visitors in Shopping Districts

Science.gov (United States)

Kawada, Ko; Yamada, Takashi; Kishimoto, Tatsuya

2014-01-01

In this study, we propose two models for predicting people’s activity. The first model is the pedestrian distribution prediction (or postdiction) model by multiple regression analysis using space syntax indices of urban fabric and people distribution data obtained from a field survey. The second model is a street choice model for visitors using multinomial logit model. We performed a questionnaire survey on the field to investigate the strolling routes of 46 visitors and obtained a total of 1211 street choices in their routes. We proposed a utility function, sum of weighted space syntax indices, and other indices, and estimated the parameters for weights on the basis of maximum likelihood. These models consider both street networks, distance from destination, direction of the street choice and other spatial compositions (numbers of pedestrians, cars, shops, and elevation). The first model explains the characteristics of the street where many people tend to walk or stay. The second model explains the mechanism underlying the street choice of visitors and clarifies the differences in the weights of street choice parameters among the various attributes, such as gender, existence of destinations, number of people, etc. For all the attributes considered, the influences of DISTANCE and DIRECTION are strong. On the other hand, the influences of Int.V, SHOPS, CARS, ELEVATION, and WIDTH are different for each attribute. People with defined destinations tend to choose streets that “have more shops, and are wider and lower”. In contrast, people with undefined destinations tend to choose streets of high Int.V. The choice of males is affected by Int.V, SHOPS, WIDTH (positive) and CARS (negative). Females prefer streets that have many shops, and couples tend to choose downhill streets. The behavior of individual persons is affected by all variables. The behavior of people visiting in groups is affected by SHOP and WIDTH (positive). PMID:25379274

Street Choice Logit Model for Visitors in Shopping Districts

Directory of Open Access Journals (Sweden)

Ko Kawada

2014-07-01

Full Text Available In this study, we propose two models for predicting people’s activity. The first model is the pedestrian distribution prediction (or postdiction model by multiple regression analysis using space syntax indices of urban fabric and people distribution data obtained from a field survey. The second model is a street choice model for visitors using multinomial logit model. We performed a questionnaire survey on the field to investigate the strolling routes of 46 visitors and obtained a total of 1211 street choices in their routes. We proposed a utility function, sum of weighted space syntax indices, and other indices, and estimated the parameters for weights on the basis of maximum likelihood. These models consider both street networks, distance from destination, direction of the street choice and other spatial compositions (numbers of pedestrians, cars, shops, and elevation. The first model explains the characteristics of the street where many people tend to walk or stay. The second model explains the mechanism underlying the street choice of visitors and clarifies the differences in the weights of street choice parameters among the various attributes, such as gender, existence of destinations, number of people, etc. For all the attributes considered, the influences of DISTANCE and DIRECTION are strong. On the other hand, the influences of Int.V, SHOPS, CARS, ELEVATION, and WIDTH are different for each attribute. People with defined destinations tend to choose streets that “have more shops, and are wider and lower”. In contrast, people with undefined destinations tend to choose streets of high Int.V. The choice of males is affected by Int.V, SHOPS, WIDTH (positive and CARS (negative. Females prefer streets that have many shops, and couples tend to choose downhill streets. The behavior of individual persons is affected by all variables. The behavior of people visiting in groups is affected by SHOP and WIDTH (positive.

Predicting longitudinal trajectories of health probabilities with random-effects multinomial logit regression.

Science.gov (United States)

Liu, Xian; Engel, Charles C

2012-12-20

Researchers often encounter longitudinal health data characterized with three or more ordinal or nominal categories. Random-effects multinomial logit models are generally applied to account for potential lack of independence inherent in such clustered data. When parameter estimates are used to describe longitudinal processes, however, random effects, both between and within individuals, need to be retransformed for correctly predicting outcome probabilities. This study attempts to go beyond existing work by developing a retransformation method that derives longitudinal growth trajectories of unbiased health probabilities. We estimated variances of the predicted probabilities by using the delta method. Additionally, we transformed the covariates' regression coefficients on the multinomial logit function, not substantively meaningful, to the conditional effects on the predicted probabilities. The empirical illustration uses the longitudinal data from the Asset and Health Dynamics among the Oldest Old. Our analysis compared three sets of the predicted probabilities of three health states at six time points, obtained from, respectively, the retransformation method, the best linear unbiased prediction, and the fixed-effects approach. The results demonstrate that neglect of retransforming random errors in the random-effects multinomial logit model results in severely biased longitudinal trajectories of health probabilities as well as overestimated effects of covariates on the probabilities. Copyright © 2012 John Wiley & Sons, Ltd.

Radiation effects on cancer mortality among A-bomb survivors, 1950-72. Comparison of some statistical models and analysis based on the additive logit model

Energy Technology Data Exchange (ETDEWEB)

Otake, M [Hiroshima Univ. (Japan). Faculty of Science

1976-12-01

Various statistical models designed to determine the effects of radiation dose on mortality of atomic bomb survivors in Hiroshima and Nagasaki from specific cancers were evaluated on the basis of a basic k(age) x c(dose) x 2 contingency table. From the aspects of application and fits of different models, analysis based on the additive logit model was applied to the mortality experience of this population during the 22year period from 1 Oct. 1950 to 31 Dec. 1972. The advantages and disadvantages of the additive logit model were demonstrated. Leukemia mortality showed a sharp rise with an increase in dose. The dose response relationship suggests a possible curvature or a log linear model, particularly if the dose estimated to be more than 600 rad were set arbitrarily at 600 rad, since the average dose in the 200+ rad group would then change from 434 to 350 rad. In the 22year period from 1950 to 1972, a high mortality risk due to radiation was observed in survivors with doses of 200 rad and over for all cancers except leukemia. On the other hand, during the latest period from 1965 to 1972 a significant risk was noted also for stomach and breast cancers. Survivors who were 9 year old or less at the time of the bomb and who were exposed to high doses of 200+ rad appeared to show a high mortality risk for all cancers except leukemia, although the number of observed deaths is yet small. A number of interesting areas are discussed from the statistical and epidemiological standpoints, i.e., the numerical comparison of risks in various models, the general evaluation of cancer mortality by the additive logit model, the dose response relationship, the relative risk in the high dose group, the time period of radiation induced cancer mortality, the difference of dose response between Hiroshima and Nagasaki and the relative biological effectiveness of neutrons.

Model-based Clustering of Categorical Time Series with Multinomial Logit Classification

Science.gov (United States)

Frühwirth-Schnatter, Sylvia; Pamminger, Christoph; Winter-Ebmer, Rudolf; Weber, Andrea

2010-09-01

A common problem in many areas of applied statistics is to identify groups of similar time series in a panel of time series. However, distance-based clustering methods cannot easily be extended to time series data, where an appropriate distance-measure is rather difficult to define, particularly for discrete-valued time series. Markov chain clustering, proposed by Pamminger and Frühwirth-Schnatter [6], is an approach for clustering discrete-valued time series obtained by observing a categorical variable with several states. This model-based clustering method is based on finite mixtures of first-order time-homogeneous Markov chain models. In order to further explain group membership we present an extension to the approach of Pamminger and Frühwirth-Schnatter [6] by formulating a probabilistic model for the latent group indicators within the Bayesian classification rule by using a multinomial logit model. The parameters are estimated for a fixed number of clusters within a Bayesian framework using an Markov chain Monte Carlo (MCMC) sampling scheme representing a (full) Gibbs-type sampler which involves only draws from standard distributions. Finally, an application to a panel of Austrian wage mobility data is presented which leads to an interesting segmentation of the Austrian labour market.

Argentine Beef Demand and Household Choices of Retail Channels

Directory of Open Access Journals (Sweden)

Gustavo Rossini

2014-07-01

Full Text Available Household choices of outlet retail channels in beef purchases depend on several characteristics related to the quality of the product, convenience and ease of purchase, and economic factors such as price, income and payment methods. The aim of this paper is to study the influence of demographic and socio-economic attributes in the choice made by argentine consumers using a Multinominal Logit Model. The results show that the total number of purchases, the type of household, payment methods, and gender and schooling years of household head are the most relevant variables in the sample.

A Subpath-based Logit Model to Capture the Correlation of Routes

Directory of Open Access Journals (Sweden)

Xinjun Lai

2016-06-01

Full Text Available A subpath-based methodology is proposed to capture the travellers’ route choice behaviours and their perceptual correlation of routes, because the original link-based style may not be suitable in application: (1 travellers do not process road network information and construct the chosen route by a link-by-link style; (2 observations from questionnaires and GPS data, however, are not always link-specific. Subpaths are defined as important portions of the route, such as major roads and landmarks. The cross-nested Logit (CNL structure is used for its tractable closed-form and its capability to explicitly capture the routes correlation. Nests represent subpaths other than links so that the number of nests is significantly reduced. Moreover, the proposed method simplifies the original link-based CNL model; therefore, it alleviates the estimation and computation difficulties. The estimation and forecast validation with real data are presented, and the results suggest that the new method is practical.

Para Krizleri Öngörüsünde Logit Model ve Sinyal Yaklaşımının Değeri: Türkiye Tecrübesi

OpenAIRE

Kaya, Vedat; Yilmaz, Omer

2007-01-01

Logit model and the signal approach are two analysis methods being commonly used to forecast and explain currency crises. Logit model is successful to determine explaining variables of crisis and to calculate the probability of crisis in particular during the period experienced with a crisis. On the other hand, the signal approach aims at determining any possible currency crisis in advance, following some variables showing unusual change over the periods of economic fluctuation and thus it pr...

Comparing Johnson’s SBB, Weibull and Logit-Logistic bivariate distributions for modeling tree diameters and heights using copulas

Energy Technology Data Exchange (ETDEWEB)

Cardil Forradellas, A.; Molina Terrén, D.M.; Oliveres, J.; Castellnou, M.

2016-07-01

Aim of study: In this study we compare the accuracy of three bivariate distributions: Johnson’s SBB, Weibull-2P and LL-2P functions for characterizing the joint distribution of tree diameters and heights. Area of study: North-West of Spain. Material and methods: Diameter and height measurements of 128 plots of pure and even-aged Tasmanian blue gum (Eucalyptus globulus Labill.) stands located in the North-west of Spain were considered in the present study. The SBB bivariate distribution was obtained from SB marginal distributions using a Normal Copula based on a four-parameter logistic transformation. The Plackett Copula was used to obtain the bivariate models from the Weibull and Logit-logistic univariate marginal distributions. The negative logarithm of the maximum likelihood function was used to compare the results and the Wilcoxon signed-rank test was used to compare the related samples of these logarithms calculated for each sample plot and each distribution. Main results: The best results were obtained by using the Plackett copula and the best marginal distribution was the Logit-logistic. Research highlights: The copulas used in this study have shown a good performance for modeling the joint distribution of tree diameters and heights. They could be easily extended for modelling multivariate distributions involving other tree variables, such as tree volume or biomass. (Author)

Analyzing Korean consumers’ latent preferences for electricity generation sources with a hierarchical Bayesian logit model in a discrete choice experiment

International Nuclear Information System (INIS)

Byun, Hyunsuk; Lee, Chul-Yong

2017-01-01

Generally, consumers use electricity without considering the source the electricity was generated from. Since different energy sources exert varying effects on society, it is necessary to analyze consumers’ latent preference for electricity generation sources. The present study estimates Korean consumers’ marginal utility and an appropriate generation mix is derived using the hierarchical Bayesian logit model in a discrete choice experiment. The results show that consumers consider the danger posed by the source of electricity as the most important factor among the effects of electricity generation sources. Additionally, Korean consumers wish to reduce the contribution of nuclear power from the existing 32–11%, and increase that of renewable energy from the existing 4–32%. - Highlights: • We derive an electricity mix reflecting Korean consumers’ latent preferences. • We use the discrete choice experiment and hierarchical Bayesian logit model. • The danger posed by the generation source is the most important attribute. • The consumers wish to increase the renewable energy proportion from 4.3% to 32.8%. • Korea's cost-oriented energy supply policy and consumers’ preference differ markedly.

Analysis of hourly crash likelihood using unbalanced panel data mixed logit model and real-time driving environmental big data.

Science.gov (United States)

Chen, Feng; Chen, Suren; Ma, Xiaoxiang

2018-06-01

Driving environment, including road surface conditions and traffic states, often changes over time and influences crash probability considerably. It becomes stretched for traditional crash frequency models developed in large temporal scales to capture the time-varying characteristics of these factors, which may cause substantial loss of critical driving environmental information on crash prediction. Crash prediction models with refined temporal data (hourly records) are developed to characterize the time-varying nature of these contributing factors. Unbalanced panel data mixed logit models are developed to analyze hourly crash likelihood of highway segments. The refined temporal driving environmental data, including road surface and traffic condition, obtained from the Road Weather Information System (RWIS), are incorporated into the models. Model estimation results indicate that the traffic speed, traffic volume, curvature and chemically wet road surface indicator are better modeled as random parameters. The estimation results of the mixed logit models based on unbalanced panel data show that there are a number of factors related to crash likelihood on I-25. Specifically, weekend indicator, November indicator, low speed limit and long remaining service life of rutting indicator are found to increase crash likelihood, while 5-am indicator and number of merging ramps per lane per mile are found to decrease crash likelihood. The study underscores and confirms the unique and significant impacts on crash imposed by the real-time weather, road surface, and traffic conditions. With the unbalanced panel data structure, the rich information from real-time driving environmental big data can be well incorporated. Copyright © 2018 National Safety Council and Elsevier Ltd. All rights reserved.

Time-varying mixed logit model for vehicle merging behavior in work zone merging areas.

Science.gov (United States)

Weng, Jinxian; Du, Gang; Li, Dan; Yu, Yao

2018-08-01

This study aims to develop a time-varying mixed logit model for the vehicle merging behavior in work zone merging areas during the merging implementation period from the time of starting a merging maneuver to that of completing the maneuver. From the safety perspective, vehicle crash probability and severity between the merging vehicle and its surrounding vehicles are regarded as major factors influencing vehicle merging decisions. Model results show that the model with the use of vehicle crash risk probability and severity could provide higher prediction accuracy than previous models with the use of vehicle speeds and gap sizes. It is found that lead vehicle type, through lead vehicle type, through lag vehicle type, crash probability of the merging vehicle with respect to the through lag vehicle, crash severities of the merging vehicle with respect to the through lead and lag vehicles could exhibit time-varying effects on the merging behavior. One important finding is that the merging vehicle could become more and more aggressive in order to complete the merging maneuver as quickly as possible over the elapsed time, even if it has high vehicle crash risk with respect to the through lead and lag vehicles. Copyright © 2018 Elsevier Ltd. All rights reserved.

Numerical proceessing of radioimmunoassay results using logit-log transformation method

International Nuclear Information System (INIS)

Textoris, R.

1983-01-01

The mathematical model and algorithm are described of the numerical processing of the results of a radioimmunoassay by the logit-log transformation method and by linear regression with weight factors. The limiting value of the curve for zero concentration is optimized with regard to the residual sum by the iterative method by multiple repeats of the linear regression. Typical examples are presented of the approximation of calibration curves. The method proved suitable for all hitherto used RIA sets and is well suited for small computers with internal memory of min. 8 Kbyte. (author)

Predicting Dropouts of University Freshmen: A Logit Regression Analysis.

Science.gov (United States)

Lam, Y. L. Jack

1984-01-01

Stepwise discriminant analysis coupled with logit regression analysis of freshmen data from Brandon University (Manitoba) indicated that six tested variables drawn from research on university dropouts were useful in predicting attrition: student status, residence, financial sources, distance from home town, goal fulfillment, and satisfaction with…

Recreation Value of Water to Wetlands in the San Joaquin Valley: Linked Multinomial Logit and Count Data Trip Frequency Models

Science.gov (United States)

Creel, Michael; Loomis, John

1992-10-01

The recreational benefits from providing increased quantities of water to wildlife and fisheries habitats is estimated using linked multinomial logit site selection models and count data trip frequency models. The study encompasses waterfowl hunting, fishing and wildlife viewing at 14 recreational resources in the San Joaquin Valley, including the National Wildlife Refuges, the State Wildlife Management Areas, and six river destinations. The economic benefits of increasing water supplies to wildlife refuges were also examined by using the estimated models to predict changing patterns of site selection and overall participation due to increases in water allocations. Estimates of the dollar value per acre foot of water are calculated for increases in water to refuges. The resulting model is a flexible and useful tool for estimating the economic benefits of alternative water allocation policies for wildlife habitat and rivers.

Risk factors associated with bus accident severity in the United States: A generalized ordered logit model

DEFF Research Database (Denmark)

Kaplan, Sigal; Prato, Carlo Giacomo

2012-01-01

of 2011. Method: The current study investigates the underlying risk factors of bus accident severity in the United States by estimating a generalized ordered logit model. Data for the analysis are retrieved from the General Estimates System (GES) database for the years 2005–2009. Results: Results show...... that accident severity increases: (i) for young bus drivers under the age of 25; (ii) for drivers beyond the age of 55, and most prominently for drivers over 65 years old; (iii) for female drivers; (iv) for very high (over 65 mph) and very low (under 20 mph) speed limits; (v) at intersections; (vi) because......Introduction: Recent years have witnessed a growing interest in improving bus safety operations worldwide. While in the United States buses are considered relatively safe, the number of bus accidents is far from being negligible, triggering the introduction of the Motor-coach Enhanced Safety Act...

Environmental regulations and plant exit: A logit analysis based on established panel data

Energy Technology Data Exchange (ETDEWEB)

Bioern, E; Golombek, R; Raknerud, A

1995-12-01

This publication uses a model to study the relationship between environmental regulations and plant exit. It has the main characteristics of a multinomial qualitative response model of the logit type, but also has elements of a Markov chain model. The model uses Norwegian panel data for establishments in three manufacturing sectors with high shares of units which have been under strict environmental regulations. In two of the sectors, the exit probability of non-regulated establishments is about three times higher than for regulated ones. It is also found that the probability of changing regulation status from non-regulated to regulated depends significantly on economic factors. In particular, establishments with weak profitability are the most likely to become subject to environmental regulation. 12 refs., 2 figs., 6 tabs.

Investigating the Differences of Single-Vehicle and Multivehicle Accident Probability Using Mixed Logit Model

Directory of Open Access Journals (Sweden)

Bowen Dong

2018-01-01

Full Text Available Road traffic accidents are believed to be associated with not only road geometric feature and traffic characteristic, but also weather condition. To address these safety issues, it is of paramount importance to understand how these factors affect the occurrences of the crashes. Existing studies have suggested that the mechanisms of single-vehicle (SV accidents and multivehicle (MV accidents can be very different. Few studies were conducted to examine the difference of SV and MV accident probability by addressing unobserved heterogeneity at the same time. To investigate the different contributing factors on SV and MV, a mixed logit model is employed using disaggregated data with the response variable categorized as no accidents, SV accidents, and MV accidents. The results indicate that, in addition to speed gap, length of segment, and wet road surfaces which are significant for both SV and MV accidents, most of other variables are significant only for MV accidents. Traffic, road, and surface characteristics are main influence factors of SV and MV accident possibility. Hourly traffic volume, inside shoulder width, and wet road surface are found to produce statistically significant random parameters. Their effects on the possibility of SV and MV accident vary across different road segments.

Efficiency Loss of Mixed Equilibrium Associated with Altruistic Users and Logit-based Stochastic Users in Transportation Network

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Xiao-Jun Yu

2014-02-01

Full Text Available The efficiency loss of mixed equilibrium associated with two categories of users is investigated in this paper. The first category of users are altruistic users (AU who have the same altruism coefficient and try to minimize their own perceived cost that assumed to be a linear combination of selfish com­ponent and altruistic component. The second category of us­ers are Logit-based stochastic users (LSU who choose the route according to the Logit-based stochastic user equilib­rium (SUE principle. The variational inequality (VI model is used to formulate the mixed route choice behaviours associ­ated with AU and LSU. The efficiency loss caused by the two categories of users is analytically derived and the relations to some network parameters are discussed. The numerical tests validate our analytical results. Our result takes the re­sults in the existing literature as its special cases.

Multiple equilibria and limit cycles in evolutonary games with Logit Dynamics

NARCIS (Netherlands)

Hommes, C.H.; Ochea, M.I.

2012-01-01

This note shows, by means of two simple, three-strategy games, the existence of stable periodic orbits and of multiple, interior steady states in a smooth version of the Best-Response Dynamics, the Logit Dynamics. The main finding is that, unlike Replicator Dynamics, generic Hopf bifurcation and

Application of LogitBoost Classifier for Traceability Using SNP Chip Data.

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Kim, Kwondo; Seo, Minseok; Kang, Hyunsung; Cho, Seoae; Kim, Heebal; Seo, Kang-Seok

2015-01-01

Consumer attention to food safety has increased rapidly due to animal-related diseases; therefore, it is important to identify their places of origin (POO) for safety purposes. However, only a few studies have addressed this issue and focused on machine learning-based approaches. In the present study, classification analyses were performed using a customized SNP chip for POO prediction. To accomplish this, 4,122 pigs originating from 104 farms were genotyped using the SNP chip. Several factors were considered to establish the best prediction model based on these data. We also assessed the applicability of the suggested model using a kinship coefficient-filtering approach. Our results showed that the LogitBoost-based prediction model outperformed other classifiers in terms of classification performance under most conditions. Specifically, a greater level of accuracy was observed when a higher kinship-based cutoff was employed. These results demonstrated the applicability of a machine learning-based approach using SNP chip data for practical traceability.

An econometric analysis of changes in arable land utilization using multinomial logit model in Pinggu district, Beijing, China.

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Xu, Yueqing; McNamara, Paul; Wu, Yanfang; Dong, Yue

2013-10-15

Arable land in China has been decreasing as a result of rapid population growth and economic development as well as urban expansion, especially in developed regions around cities where quality farmland quickly disappears. This paper analyzed changes in arable land utilization during 1993-2008 in the Pinggu district, Beijing, China, developed a multinomial logit (MNL) model to determine spatial driving factors influencing arable land-use change, and simulated arable land transition probabilities. Land-use maps, as well as social-economic and geographical data were used in the study. The results indicated that arable land decreased significantly between 1993 and 2008. Lost arable land shifted into orchard, forestland, settlement, and transportation land. Significant differences existed for arable land transitions among different landform areas. Slope, elevation, population density, urbanization rate, distance to settlements, and distance to roadways were strong drivers influencing arable land transition to other uses. The MNL model was proved effective for predicting transition probabilities in land use from arable land to other land-use types, thus can be used for scenario analysis to develop land-use policies and land-management measures in this metropolitan area. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Monte Carlo simulation study comparing linear regression, beta regression, variable-dispersion beta regression and fractional logit regression at recovering average difference measures in a two sample design.

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Meaney, Christopher; Moineddin, Rahim

2014-01-24

In biomedical research, response variables are often encountered which have bounded support on the open unit interval--(0,1). Traditionally, researchers have attempted to estimate covariate effects on these types of response data using linear regression. Alternative modelling strategies may include: beta regression, variable-dispersion beta regression, and fractional logit regression models. This study employs a Monte Carlo simulation design to compare the statistical properties of the linear regression model to that of the more novel beta regression, variable-dispersion beta regression, and fractional logit regression models. In the Monte Carlo experiment we assume a simple two sample design. We assume observations are realizations of independent draws from their respective probability models. The randomly simulated draws from the various probability models are chosen to emulate average proportion/percentage/rate differences of pre-specified magnitudes. Following simulation of the experimental data we estimate average proportion/percentage/rate differences. We compare the estimators in terms of bias, variance, type-1 error and power. Estimates of Monte Carlo error associated with these quantities are provided. If response data are beta distributed with constant dispersion parameters across the two samples, then all models are unbiased and have reasonable type-1 error rates and power profiles. If the response data in the two samples have different dispersion parameters, then the simple beta regression model is biased. When the sample size is small (N0 = N1 = 25) linear regression has superior type-1 error rates compared to the other models. Small sample type-1 error rates can be improved in beta regression models using bias correction/reduction methods. In the power experiments, variable-dispersion beta regression and fractional logit regression models have slightly elevated power compared to linear regression models. Similar results were observed if the

Analysis of Salmonella sp bacterial contamination on Vannamei Shrimp using binary logit model approach

Science.gov (United States)

Oktaviana, P. P.; Fithriasari, K.

2018-04-01

Mostly Indonesian citizen consume vannamei shrimp as their food. Vannamei shrimp also is one of Indonesian exports comodities mainstay. Vannamei shrimp in the ponds and markets could be contaminated by Salmonella sp bacteria. This bacteria will endanger human health. Salmonella sp bacterial contamination on vannamei shrimp could be affected by many factors. This study is intended to identify what factors that supposedly influence the Salmonella sp bacterial contamination on vannamei shrimp. The researchers used the testing result of Salmonella sp bacterial contamination on vannamei shrimp as response variable. This response variable has two categories: 0 = if testing result indicate that there is no Salmonella sp on vannamei shrimp; 1 = if testing result indicate that there is Salmonella sp on vannamei shrimp. There are four factors that supposedly influence the Salmonella sp bacterial contamination on vannamei shrimp, which are the testing result of Salmonella sp bacterial contamination on farmer hand swab; the subdistrict of vannamei shrimp ponds; the fish processing unit supplied by; and the pond are in hectare. This four factors used as predictor variables. The analysis used is Binary Logit Model Approach according to the response variable that has two categories. The analysis result indicates that the factors or predictor variables which is significantly affect the Salmonella sp bacterial contamination on vannamei shrimp are the testing result of Salmonella sp bacterial contamination on farmer hand swab and the subdistrict of vannamei shrimp ponds.

Exploratory multinomial logit model-based driver injury severity analyses for teenage and adult drivers in intersection-related crashes.

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Wu, Qiong; Zhang, Guohui; Ci, Yusheng; Wu, Lina; Tarefder, Rafiqul A; Alcántara, Adélamar Dely

2016-05-18

Teenage drivers are more likely to be involved in severely incapacitating and fatal crashes compared to adult drivers. Moreover, because two thirds of urban vehicle miles traveled are on signal-controlled roadways, significant research efforts are needed to investigate intersection-related teenage driver injury severities and their contributing factors in terms of driver behavior, vehicle-infrastructure interactions, environmental characteristics, roadway geometric features, and traffic compositions. Therefore, this study aims to explore the characteristic differences between teenage and adult drivers in intersection-related crashes, identify the significant contributing attributes, and analyze their impacts on driver injury severities. Using crash data collected in New Mexico from 2010 to 2011, 2 multinomial logit regression models were developed to analyze injury severities for teenage and adult drivers, respectively. Elasticity analyses and transferability tests were conducted to better understand the quantitative impacts of these factors and the teenage driver injury severity model's generality. The results showed that although many of the same contributing factors were found to be significant in the both teenage and adult driver models, certain different attributes must be distinguished to specifically develop effective safety solutions for the 2 driver groups. The research findings are helpful to better understand teenage crash uniqueness and develop cost-effective solutions to reduce intersection-related teenage injury severities and facilitate driver injury mitigation research.

The Market for Ph.D. Holders in Greece: Probit and Multinomial Logit Analysis of their Employment Status

OpenAIRE

Joan Daouli; Eirini Konstantina Nikolatou

2015-01-01

The objective of this paper is to investigate the factors influencing the probability that a Ph.D. holder in Greece will work in the academic sector, as well as the probability of his or her choosing employment in various sectors of industry and occupational categories. Probit/multinomial logit models are employed using the 2001 Census data. The empirical results indicate that being young, married, having a Ph.D. in Natural Sciences and/or in Engineering, granted by a Greek university, increa...

The Use of Financial Literacy for Growing Personal Finance

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Ardi Gunardi

2017-07-01

Full Text Available Financial literacy played an important role for everyone in managing personal finances.This research aimed to determine how the level of financial literacy in students S1 Faculty of Economics and Business, Universitas Pasundan and investigate what factors are influencing it. The observed respondents were students from the Faculty of Economics and Business, Universitas Pasundan. The research data was collected through questionnaires,descriptive analysis, and test multinominal logit. Based on the results of the research showed that the level of financial literacy from undergraduate students Universitas Pasundan was in the low category. Financial literacy was determined by gender, Greater Academic Achievement (GPA, parental education level, and parental income level;,whereas for age, year of study and residence do not contribute to the research model. The results of this study were expected to support personal financial planning of students in improving the skills of reading, analyzing, and managing their own finances, thus avoiding the daily financial problems.

Maximum Simulated Likelihood and Expectation-Maximization Methods to Estimate Random Coefficients Logit with Panel Data

DEFF Research Database (Denmark)

Cherchi, Elisabetta; Guevara, Cristian

2012-01-01

with cross-sectional or with panel data, and (d) EM systematically attained more efficient estimators than the MSL method. The results imply that if the purpose of the estimation is only to determine the ratios of the model parameters (e.g., the value of time), the EM method should be preferred. For all......The random coefficients logit model allows a more realistic representation of agents' behavior. However, the estimation of that model may involve simulation, which may become impractical with many random coefficients because of the curse of dimensionality. In this paper, the traditional maximum...... simulated likelihood (MSL) method is compared with the alternative expectation- maximization (EM) method, which does not require simulation. Previous literature had shown that for cross-sectional data, MSL outperforms the EM method in the ability to recover the true parameters and estimation time...

Analysis of the liquidity risk in credit unions: a logit multinomial approach

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Rosiane Maria Lima Gonçalves

2008-10-01

Full Text Available Liquidity risk in financial institutions is associated to balance between working capital and financial demands. Other factors that affect credit union liquidity are an unanticipated increase of withdrawals without an offsetting amount of new deposits, and the lack of ability in promoting the product geographical diversification. The objective of this study is to analyze Minas Gerais state credit union liquidity risk and its factor determinants. Financial ratios and the multinomial logit model are used. The cooperatives were classified in five categories of liquidity risk: very low, low, medium, high and very high. The empirical results indicate that high levels of liquidity are related to smaller values of the outsourcing capital use, immobilization of the turnover capital, and provision ratios. So, they are associated to larger values of the deposit total/credit operations, and asset growth ratios.

Revealing additional preference heterogeneity with an extended random parameter logit model: the case of extra virgin olive oil

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Ahmed Yangui

2014-07-01

Full Text Available Methods that account for preference heterogeneity have received a significant amount of attention in recent literature. Most of them have focused on preference heterogeneity around the mean of the random parameters, which has been specified as a function of socio-demographic characteristics. This paper aims at analyzing consumers’ preferences towards extra-virgin olive oil in Catalonia using a methodological framework with two novelties over past studies: 1 it accounts for both preference heterogeneity around the mean and the variance; and 2 it considers both socio-demographic characteristics of consumers as well as their attitudinal factors. Estimated coefficients and moments of willingness to pay (WTP distributions are compared with those obtained from alternative Random Parameter Logit (RPL models. Results suggest that the proposed framework increases the goodness-of-fit and provides more useful insights for policy analysis. The most important attributes affecting consumers’ preferences towards extra virgin olive oil are the price and the product’s origin. The consumers perceive the organic olive oil attribute negatively, as they think that it is not worth paying a premium for a product that is healthy in nature.

Multiple steady states, limit cycles and chaotic attractors in evolutionary games with Logit Dynamics

NARCIS (Netherlands)

Hommes, C.H.; Ochea, M.I.

2010-01-01

This paper investigates, by means of simple, three and four strategy games, the occurrence of periodic and chaotic behaviour in a smooth version of the Best Response Dynamics, the Logit Dynamics. The main finding is that, unlike Replicator Dynamics, generic Hopf bifurcation and thus, stable limit

Associating crash avoidance maneuvers with driver attributes and accident characteristics: a mixed logit model approach.

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Kaplan, Sigal; Prato, Carlo Giacomo

2012-01-01

The current study focuses on the propensity of drivers to engage in crash avoidance maneuvers in relation to driver attributes, critical events, crash characteristics, vehicles involved, road characteristics, and environmental conditions. The importance of avoidance maneuvers derives from the key role of proactive and state-aware road users within the concept of sustainable safety systems, as well as from the key role of effective corrective maneuvers in the success of automated in-vehicle warning and driver assistance systems. The analysis is conducted by means of a mixed logit model that represents the selection among 5 emergency lateral and speed control maneuvers (i.e., "no avoidance maneuvers," "braking," "steering," "braking and steering," and "other maneuvers) while accommodating correlations across maneuvers and heteroscedasticity. Data for the analysis were retrieved from the General Estimates System (GES) crash database for the year 2009 by considering drivers for which crash avoidance maneuvers are known. The results show that (1) the nature of the critical event that made the crash imminent greatly influences the choice of crash avoidance maneuvers, (2) women and elderly have a relatively lower propensity to conduct crash avoidance maneuvers, (3) drowsiness and fatigue have a greater negative marginal effect on the tendency to engage in crash avoidance maneuvers than alcohol and drug consumption, (4) difficult road conditions increase the propensity to perform crash avoidance maneuvers, and (5) visual obstruction and artificial illumination decrease the probability to carry out crash avoidance maneuvers. The results emphasize the need for public awareness campaigns to promote safe driving style for senior drivers and warning about the risks of driving under fatigue and distraction being comparable to the risks of driving under the influence of alcohol and drugs. Moreover, the results suggest the need to educate drivers about hazard perception, designing

Age and pedestrian injury severity in motor-vehicle crashes: a heteroskedastic logit analysis.

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Kim, Joon-Ki; Ulfarsson, Gudmundur F; Shankar, Venkataraman N; Kim, Sungyop

2008-09-01

This research explores the injury severity of pedestrians in motor-vehicle crashes. It is hypothesized that the variance of unobserved pedestrian characteristics increases with age. In response, a heteroskedastic generalized extreme value model is used. The analysis links explanatory factors with four injury outcomes: fatal, incapacitating, non-incapacitating, and possible or no injury. Police-reported crash data between 1997 and 2000 from North Carolina, USA, are used. The results show that pedestrian age induces heteroskedasticity which affects the probability of fatal injury. The effect grows more pronounced with increasing age past 65. The heteroskedastic model provides a better fit than the multinomial logit model. Notable factors increasing the probability of fatal pedestrian injury: increasing pedestrian age, male driver, intoxicated driver (2.7 times greater probability of fatality), traffic sign, commercial area, darkness with or without streetlights (2-4 times greater probability of fatality), sport-utility vehicle, truck, freeway, two-way divided roadway, speeding-involved, off roadway, motorist turning or backing, both driver and pedestrian at fault, and pedestrian only at fault. Conversely, the probability of a fatal injury decreased: with increasing driver age, during the PM traffic peak, with traffic signal control, in inclement weather, on a curved roadway, at a crosswalk, and when walking along roadway.

A mixed logit analysis of two-vehicle crash severities involving a motorcycle.

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Shaheed, Mohammad Saad B; Gkritza, Konstantina; Zhang, Wei; Hans, Zachary

2013-12-01

Using motorcycle crash data for Iowa from 2001 to 2008, this paper estimates a mixed logit model to investigate the factors that affect crash severity outcomes in a collision between a motorcycle and another vehicle. These include crash-specific factors (such as manner of collision, motorcycle rider and non-motorcycle driver and vehicle actions), roadway and environmental conditions, location and time, motorcycle rider and non-motorcycle driver and vehicle attributes. The methodological approach allows the parameters to vary across observations as opposed to a single parameter representing all observations. Our results showed non-uniform effects of rear-end collisions on minor injury crashes, as well as of the roadway speed limit greater or equal to 55mph, the type of area (urban), the riding season (summer) and motorcyclist's gender on low severity crashes. We also found significant effects of the roadway surface condition, clear vision (not obscured by moving vehicles, trees, buildings, or other), light conditions, speed limit, and helmet use on severe injury outcomes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Analisis Faktor yang Mempengaruhi Tingkat Kesehatan Bank dengan Regresi Logit

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Titik Aryati

2007-09-01

Full Text Available The article aims to find the probability effects of bank’s health level using CAMEL ratio analysis. The statistic method used to test on the research hypothesis was logit regression. The dependent variable used in this research was bank’s health level and independent variables were CAMEL financial ratios consisting of CAR, NPL, ROA, ROE, LDR, and NIM. The report data were extracted from bank’s financial from financial report, which had been published and accumulated by Infobank research bureau with valuation, based on bank Indonesia policy. The sample consisted of 60 healthy banks and 14 unhealthy banks in 2005 and 2006. The empirical result of this research indicates that the Non Performing Loan is the significant variable affecting bank health level.

Modeling pedestrian shopping behavior using principles of bounded rationality: model comparison and validation

Science.gov (United States)

Zhu, Wei; Timmermans, Harry

2011-06-01

Models of geographical choice behavior have been dominantly based on rational choice models, which assume that decision makers are utility-maximizers. Rational choice models may be less appropriate as behavioral models when modeling decisions in complex environments in which decision makers may simplify the decision problem using heuristics. Pedestrian behavior in shopping streets is an example. We therefore propose a modeling framework for pedestrian shopping behavior incorporating principles of bounded rationality. We extend three classical heuristic rules (conjunctive, disjunctive and lexicographic rule) by introducing threshold heterogeneity. The proposed models are implemented using data on pedestrian behavior in Wang Fujing Street, the city center of Beijing, China. The models are estimated and compared with multinomial logit models and mixed logit models. Results show that the heuristic models are the best for all the decisions that are modeled. Validation tests are carried out through multi-agent simulation by comparing simulated spatio-temporal agent behavior with the observed pedestrian behavior. The predictions of heuristic models are slightly better than those of the multinomial logit models.

Pricing and lot sizing optimization in a two-echelon supply chain with a constrained Logit demand function

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Yeison Díaz-Mateus

2017-07-01

Full Text Available Decision making in supply chains is influenced by demand variations, and hence sales, purchase orders and inventory levels are therefore concerned. This paper presents a non-linear optimization model for a two-echelon supply chain, for a unique product. In addition, the model includes the consumers’ maximum willingness to pay, taking socioeconomic differences into account. To do so, the constrained multinomial logit for discrete choices is used to estimate demand levels. Then, a metaheuristic approach based on particle swarm optimization is proposed to determine the optimal product sales price and inventory coordination variables. To validate the proposed model, a supply chain of a technological product was chosen and three scenarios are analyzed: discounts, demand segmentation and demand overestimation. Results are analyzed on the basis of profits, lotsizing and inventory turnover and market share. It can be concluded that the maximum willingness to pay must be taken into consideration, otherwise fictitious profits may mislead decision making, and although the market share would seem to improve, overall profits are not in fact necessarily better.

Stochastic modeling of consumer preferences for health care institutions.

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Malhotra, N K

1983-01-01

This paper proposes a stochastic procedure for modeling consumer preferences via LOGIT analysis. First, a simple, non-technical exposition of the use of a stochastic approach in health care marketing is presented. Second, a study illustrating the application of the LOGIT model in assessing consumer preferences for hospitals is given. The paper concludes with several implications of the proposed approach.

Sample size determination for logistic regression on a logit-normal distribution.

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Kim, Seongho; Heath, Elisabeth; Heilbrun, Lance

2017-06-01

Although the sample size for simple logistic regression can be readily determined using currently available methods, the sample size calculation for multiple logistic regression requires some additional information, such as the coefficient of determination ([Formula: see text]) of a covariate of interest with other covariates, which is often unavailable in practice. The response variable of logistic regression follows a logit-normal distribution which can be generated from a logistic transformation of a normal distribution. Using this property of logistic regression, we propose new methods of determining the sample size for simple and multiple logistic regressions using a normal transformation of outcome measures. Simulation studies and a motivating example show several advantages of the proposed methods over the existing methods: (i) no need for [Formula: see text] for multiple logistic regression, (ii) available interim or group-sequential designs, and (iii) much smaller required sample size.

Early Warning Models for Systemic Banking Crises in Montenegro

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Željka Asanović

2013-06-01

Full Text Available The purpose of this research is to create an adequate early warning model for systemic banking crises in Montenegro. The probability of banking crisis occurrence is calculated using discrete dependent variable models, more precisely, estimating logit regression. Afterwards, seven simple logit regressions that individually have two explanatory variables are estimated. Adequate weights have been assigned to all seven regressions using the technique of Bayesian model averaging. The advantage of this technique is that it takes into account the model uncertainty by considering various combinations of models in order to minimize the author’s subjective judgment when determining reliable early warning indicators. The results of Bayesian model averaging largely coincide with the results of a previously estimated dynamic logit model. Indicators of credit expansion, thanks to their performances, have a dominant role in early warning models for systemic banking crises in Montenegro. The results have also shown that the Montenegrin banking system is significantly exposed to trends on the global level.

The consumer’s choice among television displays: A multinomial logit approach

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Carlos Giovanni González Espitia

2013-07-01

Full Text Available The consumer’s choice over a bundle of products depends on observable and unobservable characteristics of goods and consumers. This choice is made in order to maximize utility subject to a budget constraint. At the same time, firms make product differentiation decisions to maximize profit. Quality is a form of differentiation. An example of this occurs in the TV market, where several displays are developed. Our objective is to determine the probability for a consumer of choosing a type of display from among five kinds: standard tube, LCD, plasma, projection and LED. Using a multinomial logit approach, we find that electronic appliances like DVDs and audio systems, as well as socioeconomic status, increase the probability of choosing a high-tech television display. Our empirical approximation contributes to further understanding rational consumer behavior through the theory of utility maximization and highlights the importance of studying market structure and analyzing changes in welfare and efficiency.

—: A Multicategory Brand Equity Model and Its Application at Allstate

OpenAIRE

Venkatesh Shankar; Pablo Azar; Matthew Fuller

2008-01-01

We develop a robust model for estimating, tracking, and managing brand equity for multicategory brands based on customer survey and financial measures. This model has two components: (1) offering value (computed from discounted cash flow analysis) and (2) relative brand importance (computed from brand choice models such as multinomial logit, heteroscedastic extreme value, and mixed logit). We apply this model to estimate the brand equity of Allstate—a leading insurance company—and its leading...

Modeling Stochastic Route Choice Behaviors with Equivalent Impedance

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Jun Li

2015-01-01

Full Text Available A Logit-based route choice model is proposed to address the overlapping and scaling problems in the traditional multinomial Logit model. The nonoverlapping links are defined as a subnetwork, and its equivalent impedance is explicitly calculated in order to simply network analyzing. The overlapping links are repeatedly merged into subnetworks with Logit-based equivalent travel costs. The choice set at each intersection comprises only the virtual equivalent route without overlapping. In order to capture heterogeneity in perception errors of different sizes of networks, different scale parameters are assigned to subnetworks and they are linked to the topological relationships to avoid estimation burden. The proposed model provides an alternative method to model the stochastic route choice behaviors without the overlapping and scaling problems, and it still maintains the simple and closed-form expression from the MNL model. A link-based loading algorithm based on Dial’s algorithm is proposed to obviate route enumeration and it is suitable to be applied on large-scale networks. Finally a comparison between the proposed model and other route choice models is given by numerical examples.

Modelling Preference Heterogeneity for Theatre Tickets

DEFF Research Database (Denmark)

Baldin, Andrea; Bille, Trine

2018-01-01

This article analyses the behavioural choice for theatre tickets using a rich data set for 2010–2013 from the sale system of the Royal Danish National Theatre. A consumer who decides to attend a theatre production faces multiple sources of price variation that involves a choice by the consumer...... among different ticket alternatives. Three modelling approaches are proposed in order to model ticket purchases: conditional logit with socio-demographic characteristics, nested logit and latent class. These models allow us explicitly to take into account consumers’ preference heterogeneity with respect...... of behaviour in the choice of theatre ticket....

FACTORS THAT AFFECT TRANSPORT MODE PREFERENCE FOR GRADUATE STUDENTS IN THE NATIONAL UNIVERSITY OF MALAYSIA BY LOGIT METHOD

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ALI AHMED MOHAMMED

2013-06-01

Full Text Available A study was carried out to examine the perceptions and preferences of students on choosing the type of transportation for their travels in university campus. This study focused on providing personal transport users road transport alternatives as a countermeasure aimed at shifting car users to other modes of transportation. Overall 456 questionnaires were conducted to develop a choice of transportation mode preferences. Consequently, Logit model and SPSS were used to identify the factors that affect the determination of the choice of transportation mode. Results indicated that by reducing travel time by 70% the amount of private cars users will be reduced by 84%, while reduction the travel cost was found to be highly improving the public modes of utilization. This study revealed positive aspects is needed to shift travellers from private modes to public. The positive aspect contributes to travel time and travel cost reduction, hence improving the services, whereby contributing to sustainability.

Valoração de contingente pelas modelagens logit e análise multivariada: um estudo de caso da disposição a aceitar compensação dos cafeicultores vinculados ao PRO-CAFÉ de Viçosa - MG Contingent valuation with modeling logit and multivariate analyses: a case study of the willingness of coffee planters linked to the PRO-COFFEE of Viçosa - MG to accept compensation

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Pedro Silveira Máximo

2009-12-01

Full Text Available O objetivo deste estudo foi, justamente, identificar, entre os métodos LOGIT e a análise multivariada, qual a mais eficaz para estimar a Disposição a Aceitar Compensação (DAC dos cafeicultores quando o viés da utilidade marginal é passível de ocorrência. Para tal, foi elaborado um formulário com 33 perguntas envolvendo informações sobre características socioeconômicas dos cafeicultores, o uso da metodologia de valoração de contingente (MVC e do veículo de pagamento dos "Jogos de Lances", que revelou a Disposição a Aceitar uma Compensação (DAC na troca de um hectare de café por um hectare de mata. Como esperado, por causa do viés da utilidade marginal o método LOGIT foi incapaz de produzir resultados consistentes. Já a estimação da DAC pela análise multivariada mostrou que, caso o governo estivesse disposto a aumentar a provisão de mata em 70 ha, ele deveria despender 254.200 reais por ano, tratando apenas dos cafeicultores vinculados ao programa do PRO-CAFÉ.The object of this study was to identify which method, either LOGIT or multivariate analyses, was the most efficient to estimate the coffee planters' Willingness to Accept a Compensation, when there was a possibility of occurrence of marginal utility. For such, a questionnaire was formulated, with 33 questions involving information on coffee planters' socio - economic characteristics, the use of the methodology of contingent valuation (MCV, and the payment of the "offer game" that reveled the willingness to accept a compensation (WAC, by exchanging a hectare of coffee by a hectare of forest. As expected, because of the marginal utility's bias, the LOGIT method was unable to produce consistent results. However, when the WAC was estimated by multivariate analyses, the results showed that if the government is willing to increase the provision of forest to 70 hectares, it should pay out 254,200 reais (around 116,000 dollars, dealing only with the coffee planters

Think twice before you book? Modelling the choice of public vs private dentist in a choice experiment.

Science.gov (United States)

Kiiskinen, Urpo; Suominen-Taipale, Anna Liisa; Cairns, John

2010-06-01

This study concerns the choice of primary dental service provider by consumers. If the health service delivery system allows individuals to choose between public-care providers or if complementary private services are available, it is typically assumed that utilisation is a three-stage decision process. The patient first makes a decision to seek care, and then chooses the service provider. The final stage, involving decisions over the amount and form of treatment, is not considered here. The paper reports a discrete choice experiment (DCE) designed to evaluate attributes affecting individuals' choice of dental-care provider. The feasibility of the DCE approach in modelling consumers' choice in the context of non-acute need for dental care is assessed. The aim is to test whether a separate two-stage logit, a multinomial logit, or a nested logit best fits the choice process of consumers. A nested logit model of indirect utility functions is estimated and inclusive value (IV) constraints are tested for modelling implications. The results show that non-trading behaviour has an impact on the choice of appropriate modelling technique, but is to some extent dependent on the choice of scenarios offered. It is concluded that for traders multinomial logit is appropriate, whereas for non-traders and on average the nested logit is the method supported by the analyses. The consistent finding in all subgroup analyses is that the traditional two-stage decision process is found to be implausible in the context of consumer's choice of dental-care provider.

Patient choice modelling: how do patients choose their hospitals?

Science.gov (United States)

Smith, Honora; Currie, Christine; Chaiwuttisak, Pornpimol; Kyprianou, Andreas

2018-06-01

As an aid to predicting future hospital admissions, we compare use of the Multinomial Logit and the Utility Maximising Nested Logit models to describe how patients choose their hospitals. The models are fitted to real data from Derbyshire, United Kingdom, which lists the postcodes of more than 200,000 admissions to six different local hospitals. Both elective and emergency admissions are analysed for this mixed urban/rural area. For characteristics that may affect a patient's choice of hospital, we consider the distance of the patient from the hospital, the number of beds at the hospital and the number of car parking spaces available at the hospital, as well as several statistics publicly available on National Health Service (NHS) websites: an average waiting time, the patient survey score for ward cleanliness, the patient safety score and the inpatient survey score for overall care. The Multinomial Logit model is successfully fitted to the data. Results obtained with the Utility Maximising Nested Logit model show that nesting according to city or town may be invalid for these data; in other words, the choice of hospital does not appear to be preceded by choice of city. In all of the analysis carried out, distance appears to be one of the main influences on a patient's choice of hospital rather than statistics available on the Internet.

UN MODELO LOGIT PARA LA FRAGILIDAD DEL SISTEMA FINANCIERO VENEZOLANO DENTRO DEL CONTEXTO DE LOS PROCESOS DE FUSIÓN E INTERVENCIÓN | A LOGIT APPROACH OF THE VENEZUELAN FINANCIAL SYSTEM WITHIN THE CONTEXT OF MERGER AND INTERVENTION

Directory of Open Access Journals (Sweden)

César Rubicundo

2016-08-01

Full Text Available In Venezuela there have been more than 30 mergers, after the approval of the Banking Act in 1999, since from 103 institutions, the financial system closed the year 2013 with 35 brokerage firms, which represents a decrease of 66% due to 20 coalitions, 30 transformations and 18 settlements. Therefore, an analysis is proposed of the current economic situation of the financial system in the context of mergers and interventions, considering internal and external factors according to the constituted capital. The study was based on information from 37 private capital institutions and 04 public institutions, between January 2009 and December 2013. The previous analysis for privately held banks, showed that these institutions have a 78.40% chance of not incurring in situations of fragility; while the State capital banks have 83.30% of surviving in the market. As for the estimated logit models, it was found that the liquidity ratio, ROE, management index and inflation, are components that push towards a fragile situation for privately held banks, with a probability forecast of fragility. With regard to the state capital banks, this situation is explained by a 62.50% equity index, ROE, and inflation. A probability of stability for these banks is expected. The joint model forecasted a probability of a stable financial system for the coming months.

Analyzing the preference for non-exclusive forms of telecommuting: Modeling and policy implications

OpenAIRE

Bagley, Michael N.; Mokhtarian, Patricia L.

1997-01-01

This study examines three models of the individual’s preference for home- and center-based telecommuting. Issues concerning the estimation of discrete models when the alternatives are non-exclusive are discussed. Two binary logit models are presented, one on the preference to telecommute from a center versus not telecommuting from a center (adjusted p2 = 0.24), and the other on the preference to telecommute from a center over telecommuting from home (adjusted 2 =0.64). A nested logit model is...

Regression Models For Multivariate Count Data.

Science.gov (United States)

Zhang, Yiwen; Zhou, Hua; Zhou, Jin; Sun, Wei

2017-01-01

Data with multivariate count responses frequently occur in modern applications. The commonly used multinomial-logit model is limiting due to its restrictive mean-variance structure. For instance, analyzing count data from the recent RNA-seq technology by the multinomial-logit model leads to serious errors in hypothesis testing. The ubiquity of over-dispersion and complicated correlation structures among multivariate counts calls for more flexible regression models. In this article, we study some generalized linear models that incorporate various correlation structures among the counts. Current literature lacks a treatment of these models, partly due to the fact that they do not belong to the natural exponential family. We study the estimation, testing, and variable selection for these models in a unifying framework. The regression models are compared on both synthetic and real RNA-seq data.

Stability of Mixed-Strategy-Based Iterative Logit Quantal Response Dynamics in Game Theory

Science.gov (United States)

Zhuang, Qian; Di, Zengru; Wu, Jinshan

2014-01-01

Using the Logit quantal response form as the response function in each step, the original definition of static quantal response equilibrium (QRE) is extended into an iterative evolution process. QREs remain as the fixed points of the dynamic process. However, depending on whether such fixed points are the long-term solutions of the dynamic process, they can be classified into stable (SQREs) and unstable (USQREs) equilibriums. This extension resembles the extension from static Nash equilibriums (NEs) to evolutionary stable solutions in the framework of evolutionary game theory. The relation between SQREs and other solution concepts of games, including NEs and QREs, is discussed. Using experimental data from other published papers, we perform a preliminary comparison between SQREs, NEs, QREs and the observed behavioral outcomes of those experiments. For certain games, we determine that SQREs have better predictive power than QREs and NEs. PMID:25157502

Comparison of four mathematical models for the calculation of radioimmunoassay data of LH, FSH and GH

International Nuclear Information System (INIS)

Geier, T.; Rohde, W.

1981-01-01

Weighted linear logit-log regression, point-to-point logit-log interpolation, smoothing spline approximation and the four-parameter logistic function calculated by non-linear regression have been compared. The data for comparison have been obtained from two different pool-sera for each of the LH-, FSH- and GH-RIA and from the basal serum LH values of two populations of children. The Wilcoxon matched pairs signed rank test was used for comparison: For GH there is no significant difference between all methods, for FSH the weighted linear logit-log regression and spline approximation appeared to be equivalent, but for LH no unequivocal assertion can be made. There is no significant difference between the mathematical models for determination of hormone concentration within one assay run of a population as exemplified for LH. In addition, pool sera data were subjected to an analysis of variance and the comparison of the results revealed that the different models did not lead to different statements about assay performance. The point-to-point logit-log interpolation is proposed as most simple curvilinear approximation for assays which cannot be linearized by logit-log transformation. (author)

Discrete choice models for commuting interactions

DEFF Research Database (Denmark)

Rouwendal, Jan; Mulalic, Ismir; Levkovich, Or

An emerging quantitative spatial economics literature models commuting interactions by a gravity equation that is mathematically equivalent to a multinomial logit model. This model is widely viewed as restrictive because of the independence of irrelevant alternatives (IIA) property that links sub...

Intercity Travel Demand Analysis Model

Directory of Open Access Journals (Sweden)

Ming Lu

2014-01-01

Full Text Available It is well known that intercity travel is an important component of travel demand which belongs to short distance corridor travel. The conventional four-step method is no longer suitable for short distance corridor travel demand analysis for the time spent on urban traffic has a great impact on traveler's main mode choice. To solve this problem, the author studied the existing intercity travel demand analysis model, then improved it based on the study, and finally established a combined model of main mode choice and access mode choice. At last, an integrated multilevel nested logit model structure system was built. The model system includes trip generation, destination choice, and mode-route choice based on multinomial logit model, and it achieved linkage and feedback of each part through logsum variable. This model was applied in Shenzhen intercity railway passenger demand forecast in 2010 as a case study. As a result, the forecast results were consistent with the actuality. The model's correctness and feasibility were verified.

Comparison on models for genetic evaluation of non-return rate and success in first insemination of the Danish Holstein cow

DEFF Research Database (Denmark)

Sun, C; Su, G

2010-01-01

The aim of is study was to compare a linear Gaussian model with logit model and probit model for genetic evaluation of non-return rate within 56 d after first-insemination (NRR56) and success in first insemination (SFI). The whole dataset used in the analysis contained 471,742 records from...... the EBV of proven bulls, obtained from the whole dataset and from a reduced dataset which only contains the first-crop daughters of sires; 2) χ2 statistic for the expected and observed frequency in a cross validation. Heritabilities estimated using linear, probit and logit models were 0.011, 0.014 and 0....... Model validation showed that there was no difference between probit model and logit model, but the two models were better than linear model in stability and predictive ability for genetic evaluation of NRR56 and SFI. However, based on the whole dataset, the correlations between EBV estimated using...

Hybrid discrete choice models: Gained insights versus increasing effort

Energy Technology Data Exchange (ETDEWEB)

Mariel, Petr, E-mail: petr.mariel@ehu.es [UPV/EHU, Economía Aplicada III, Avda. Lehendakari Aguire, 83, 48015 Bilbao (Spain); Meyerhoff, Jürgen [Institute for Landscape Architecture and Environmental Planning, Technical University of Berlin, D-10623 Berlin, Germany and The Kiel Institute for the World Economy, Duesternbrooker Weg 120, 24105 Kiel (Germany)

2016-10-15

Hybrid choice models expand the standard models in discrete choice modelling by incorporating psychological factors as latent variables. They could therefore provide further insights into choice processes and underlying taste heterogeneity but the costs of estimating these models often significantly increase. This paper aims at comparing the results from a hybrid choice model and a classical random parameter logit. Point of departure for this analysis is whether researchers and practitioners should add hybrid choice models to their suite of models routinely estimated. Our comparison reveals, in line with the few prior studies, that hybrid models gain in efficiency by the inclusion of additional information. The use of one of the two proposed approaches, however, depends on the objective of the analysis. If disentangling preference heterogeneity is most important, hybrid model seems to be preferable. If the focus is on predictive power, a standard random parameter logit model might be the better choice. Finally, we give recommendations for an adequate use of hybrid choice models based on known principles of elementary scientific inference. - Highlights: • The paper compares performance of a Hybrid Choice Model (HCM) and a classical Random Parameter Logit (RPL) model. • The HCM indeed provides insights regarding preference heterogeneity not gained from the RPL. • The RPL has similar predictive power as the HCM in our data. • The costs of estimating HCM seem to be justified when learning more on taste heterogeneity is a major study objective.

Hybrid discrete choice models: Gained insights versus increasing effort

International Nuclear Information System (INIS)

Mariel, Petr; Meyerhoff, Jürgen

2016-01-01

Hybrid choice models expand the standard models in discrete choice modelling by incorporating psychological factors as latent variables. They could therefore provide further insights into choice processes and underlying taste heterogeneity but the costs of estimating these models often significantly increase. This paper aims at comparing the results from a hybrid choice model and a classical random parameter logit. Point of departure for this analysis is whether researchers and practitioners should add hybrid choice models to their suite of models routinely estimated. Our comparison reveals, in line with the few prior studies, that hybrid models gain in efficiency by the inclusion of additional information. The use of one of the two proposed approaches, however, depends on the objective of the analysis. If disentangling preference heterogeneity is most important, hybrid model seems to be preferable. If the focus is on predictive power, a standard random parameter logit model might be the better choice. Finally, we give recommendations for an adequate use of hybrid choice models based on known principles of elementary scientific inference. - Highlights: • The paper compares performance of a Hybrid Choice Model (HCM) and a classical Random Parameter Logit (RPL) model. • The HCM indeed provides insights regarding preference heterogeneity not gained from the RPL. • The RPL has similar predictive power as the HCM in our data. • The costs of estimating HCM seem to be justified when learning more on taste heterogeneity is a major study objective.

Identification and comparison of predictive models of rectal and bladder toxicity in the case of prostatic irradiation; Identification et comparaison de modeles predictifs de toxicite rectale et vesicale en cas d'irradiation prostatique

Energy Technology Data Exchange (ETDEWEB)

Gnep, K.; Chira, C.; Le Prise, E.; Crevoisier, R. de [Centre Eugene-Marquis, Rennes (France); Zhu, J.; Simon, A.; Ospina Arango, J.D. [Inserm U642, Rennes (France); Messai, T.; Bossi, A. [Institut Gustave-Roussy, Villejuif (France); Beckendorf, V. [Centre Alexis-Vautrin, Nancy (France)

2011-10-15

More than 400 patients have been treated by conformational radiation therapy for a localized prostate adenocarcinoma and some have been selected according to the availability of dose-volume histograms. Predictive models of rectal and bladder toxicity have been compared: LKB, Logit EUD and Poisson EUD for rectal toxicity, LKB, Logit EUD, Poisson EUD and Schultheiss for bladder toxicity. Results suggest that these models could be used during the inverse planning of intensity-modulated radiation therapy in order to decrease toxicity. Short communication

Using continuation-ratio logits to analyze the variation of the age composition of fish catches

DEFF Research Database (Denmark)

Kvist, Trine; Gislason, Henrik; Thyregod, Poul

2000-01-01

Major sources of information for the estimation of the size of the fish stocks and the rate of their exploitation are samples from which the age composition of catches may be determined However, the age composition in the catches often varies as a result of several factors. Stratification...... of the sampling is desirable, because it leads to better estimates of the age composition, and the corresponding variances and covariances. The analysis is impeded by the fact that the response is ordered categorical. This paper introduces an easily applicable method to analyze such data. The method combines...... be applied separately to each level of the logits. The method is illustrated by the analysis of age-composition data collected from the Danish sandeel fishery in the North Sea in 1993. The significance of possible sources of variation is evaluated, and formulae for estimating the proportions of each age...

Staying Power of Churn Prediction Models

NARCIS (Netherlands)

Risselada, Hans; Verhoef, Peter C.; Bijmolt, Tammo H. A.

In this paper, we study the staying power of various churn prediction models. Staying power is defined as the predictive performance of a model in a number of periods after the estimation period. We examine two methods, logit models and classification trees, both with and without applying a bagging

"Logits and Tigers and Bears, Oh My! A Brief Look at the Simple Math of Logistic Regression and How It Can Improve Dissemination of Results"

Directory of Open Access Journals (Sweden)

Jason W. Osborne

2012-06-01

Full Text Available Logistic regression is slowly gaining acceptance in the social sciences, and fills an important niche in the researcher's toolkit: being able to predict important outcomes that are not continuous in nature. While OLS regression is a valuable tool, it cannot routinely be used to predict outcomes that are binary or categorical in nature. These outcomes represent important social science lines of research: retention in, or dropout from school, using illicit drugs, underage alcohol consumption, antisocial behavior, purchasing decisions, voting patterns, risky behavior, and so on. The goal of this paper is to briefly lead the reader through the surprisingly simple mathematics that underpins logistic regression: probabilities, odds, odds ratios, and logits. Anyone with spreadsheet software or a scientific calculator can follow along, and in turn, this knowledge can be used to make much more interesting, clear, and accurate presentations of results (especially to non-technical audiences. In particular, I will share an example of an interaction in logistic regression, how it was originally graphed, and how the graph was made substantially more user-friendly by converting the original metric (logits to a more readily interpretable metric (probability through three simple steps.

Classification rates: non‐parametric verses parametric models using ...

African Journals Online (AJOL)

This research sought to establish if non parametric modeling achieves a higher correct classification ratio than a parametric model. The local likelihood technique was used to model fit the data sets. The same sets of data were modeled using parametric logit and the abilities of the two models to correctly predict the binary ...

Modeling the Joint Choice Decisions on Urban Shopping Destination and Travel-to-Shop Mode: A Comparative Study of Different Structures

Directory of Open Access Journals (Sweden)

Chuan Ding

2014-01-01

Full Text Available The joint choice of shopping destination and travel-to-shop mode in downtown area is described by making use of the cross-nested logit (CNL model structure that allows for potential interalternative correlation along the both choice dimensions. Meanwhile, the traditional multinomial logit (MNL model and nested logit (NL model are also formulated, respectively. This study uses the data collected in the downtown areas of Maryland-Washington, D.C. region, for shopping trips, considering household, individual, land use, and travel related characteristics. The results of the model reveal the significant influencing factors on joint choice travel behavior between shopping destination and travel mode. A comparison of the different models shows that the proposed CNL model structure offers significant improvements in capturing unobserved correlations between alternatives over MNL model and NL model. Moreover, a Monte Carlo simulation for a group of scenarios assuming that there is an increase in parking fees in downtown area is undertaken to examine the impact of a change in car travel cost on the joint choice of shopping destination and travel mode switching. The results are expected to give a better understanding on the shopping travel behavior.

The effects of motivational factors on car use: a multidisciplinary modelling approach

Energy Technology Data Exchange (ETDEWEB)

Steg, L.; Ras, M. [University of Groningen (Netherlands). Centre for Environmental and Traffic Psychology; Geurs, K. [National Institute of Public Health and Environment, Bilthoven (Netherlands)

2001-11-01

Current transport models usually do not take motivational factors into account, and if they do, it is only implicitly. This paper presents a modelling approach aimed at explicitly examining the effects of motivational factors on present and future car use in the Netherlands. A car-use forecasting model for the years 2010 and 2020 was constructed on the basis of (i) a multinominal regression analysis, which revealed the importance of a motivational variable (viz., problem awareness) in explaining current car-use behavior separate from socio-demographic and socio-economic variables, and (ii) a population model constructed to forecast the size and composition of the Dutch population. The results show that car use could be better explained by taking motivational factors explicitly into account, and that the level of car use forecast might change significantly if changes in motivations are assumed. The question on how motivational factors could be incorporated into current (Dutch) national transport models was also addressed. (author)

Modeling patterns in count data using loglinear and related models

International Nuclear Information System (INIS)

Atwood, C.L.

1995-12-01

This report explains the use of loglinear and logit models, for analyzing Poisson and binomial counts in the presence of explanatory variables. The explanatory variables may be unordered categorical variables or numerical variables, or both. The report shows how to construct models to fit data, and how to test whether a model is too simple or too complex. The appropriateness of the methods with small data sets is discussed. Several example analyses, using the SAS computer package, illustrate the methods

UPTRANS: an incremental transport model with feedback for quick-response strategy evaluation

CSIR Research Space (South Africa)

Venter, C

2009-07-01

Full Text Available The paper describes the development of a prototype transport model to be used for high-level evaluation of a potentially large number of alternative land use-transport scenarios. It uses advanced logit modelling to capture travel behaviour change...

How bicycle level of traffic stress correlate with reported cyclist accidents injury severities: A geospatial and mixed logit analysis.

Science.gov (United States)

Chen, Chen; Anderson, Jason C; Wang, Haizhong; Wang, Yinhai; Vogt, Rachel; Hernandez, Salvador

2017-11-01

Transportation agencies need efficient methods to determine how to reduce bicycle accidents while promoting cycling activities and prioritizing safety improvement investments. Many studies have used standalone methods, such as level of traffic stress (LTS) and bicycle level of service (BLOS), to better understand bicycle mode share and network connectivity for a region. However, in most cases, other studies rely on crash severity models to explain what variables contribute to the severity of bicycle related crashes. This research uniquely correlates bicycle LTS with reported bicycle crash locations for four cities in New Hampshire through geospatial mapping. LTS measurements and crash locations are compared visually using a GIS framework. Next, a bicycle injury severity model, that incorporates LTS measurements, is created through a mixed logit modeling framework. Results of the visual analysis show some geospatial correlation between higher LTS roads and "Injury" type bicycle crashes. It was determined, statistically, that LTS has an effect on the severity level of bicycle crashes and high LTS can have varying effects on severity outcome. However, it is recommended that further analyses be conducted to better understand the statistical significance and effect of LTS on injury severity. As such, this research will validate the use of LTS as a proxy for safety risk regardless of the recorded bicycle crash history. This research will help identify the clustering patterns of bicycle crashes on high-risk corridors and, therefore, assist with bicycle route planning and policy making. This paper also suggests low-cost countermeasures or treatments that can be implemented to address high-risk areas. Specifically, with the goal of providing safer routes for cyclists, such countermeasures or treatments have the potential to substantially reduce the number of fatalities and severe injuries. Published by Elsevier Ltd.

Modelling of binary logistic regression for obesity among secondary students in a rural area of Kedah

Science.gov (United States)

Kamaruddin, Ainur Amira; Ali, Zalila; Noor, Norlida Mohd.; Baharum, Adam; Ahmad, Wan Muhamad Amir W.

2014-07-01

Logistic regression analysis examines the influence of various factors on a dichotomous outcome by estimating the probability of the event's occurrence. Logistic regression, also called a logit model, is a statistical procedure used to model dichotomous outcomes. In the logit model the log odds of the dichotomous outcome is modeled as a linear combination of the predictor variables. The log odds ratio in logistic regression provides a description of the probabilistic relationship of the variables and the outcome. In conducting logistic regression, selection procedures are used in selecting important predictor variables, diagnostics are used to check that assumptions are valid which include independence of errors, linearity in the logit for continuous variables, absence of multicollinearity, and lack of strongly influential outliers and a test statistic is calculated to determine the aptness of the model. This study used the binary logistic regression model to investigate overweight and obesity among rural secondary school students on the basis of their demographics profile, medical history, diet and lifestyle. The results indicate that overweight and obesity of students are influenced by obesity in family and the interaction between a student's ethnicity and routine meals intake. The odds of a student being overweight and obese are higher for a student having a family history of obesity and for a non-Malay student who frequently takes routine meals as compared to a Malay student.

Advances in nonmarket valuation econometrics: Spatial heterogeneity in hedonic pricing models and preference heterogeneity in stated preference models

Science.gov (United States)

Yoo, Jin Woo

In my 1st essay, the study explores Pennsylvania residents. willingness to pay for development of renewable energy technologies such as solar power, wind power, biomass electricity, and other renewable energy using a choice experiment method. Principle component analysis identified 3 independent attitude components that affect the variation of preference, a desire for renewable energy and environmental quality and concern over cost. The results show that urban residents have a higher desire for environmental quality and concern less about cost than rural residents and consequently have a higher willingness to pay to increase renewable energy production. The results of sub-sample analysis show that a representative respondent in rural (urban) Pennsylvania is willing to pay 3.8(5.9) and 4.1(5.7)/month for increasing the share of Pennsylvania electricity generated from wind power and other renewable energy by 1 percent point, respectively. Mean WTP for solar and biomass electricity was not significantly different from zero. In my second essay, heterogeneity of individual WTP for various renewable energy technologies is investigated using several different variants of the multinomial logit model: a simple MNL with interaction terms, a latent class choice model, a random parameter mixed logit choice model, and a random parameter-latent class choice model. The results of all models consistently show that respondents. preference for individual renewable technology is heterogeneous, but the degree of heterogeneity differs for different renewable technologies. In general, the random parameter logit model with interactions and a hybrid random parameter logit-latent class model fit better than other models and better capture respondents. heterogeneity of preference for renewable energy. The impact of the land under agricultural conservation easement (ACE) contract on the values of nearby residential properties is investigated using housing sales data in two Pennsylvania

SU-D-204-05: Fitting Four NTCP Models to Treatment Outcome Data of Salivary Glands Recorded Six Months After Radiation Therapy for Head and Neck Tumors

Energy Technology Data Exchange (ETDEWEB)

Mavroidis, P; Price, A; Kostich, M; Green, R; Das, S; Marks, L; Chera, B [University North Carolina, Chapel Hill, NC (United States); Amdur, R; Mendenhall, W [University of Florida, Gainesville, FL (United States); Sheets, N [University of North Carolina, Raleigh, NC (United States)

2016-06-15

Purpose: To estimate the radiobiological parameters of four popular NTCP models that describe the dose-response relations of salivary glands to the severity of patient reported dry mouth 6 months post chemo-radiotherapy. To identify the glands, which best correlate with the manifestation of those clinical endpoints. Finally, to evaluate the goodness-of-fit of the NTCP models. Methods: Forty-three patients were treated on a prospective multiinstitutional phase II study for oropharyngeal squamous cell carcinoma. All the patients received 60 Gy IMRT and they reported symptoms using the novel patient reported outcome version of the CTCAE. We derived the individual patient dosimetric data of the parotid and submandibular glands (SMG) as separate structures as well as combinations. The Lyman-Kutcher-Burman (LKB), Relative Seriality (RS), Logit and Relative Logit (RL) NTCP models were used to fit the patients data. The fitting of the different models was assessed through the area under the receiver operating characteristic curve (AUC) and the Odds Ratio methods. Results: The AUC values were highest for the contralateral parotid for Grade ≥ 2 (0.762 for the LKB, RS, Logit and 0.753 for the RL). For the salivary glands the AUC values were: 0.725 for the LKB, RS, Logit and 0.721 for the RL. For the contralateral SMG the AUC values were: 0.721 for LKB, 0.714 for Logit and 0.712 for RS and RL. The Odds Ratio for the contralateral parotid was 5.8 (1.3–25.5) for all the four NTCP models for the radiobiological dose threshold of 21Gy. Conclusion: It was shown that all the examined NTCP models could fit the clinical data well with very similar accuracy. The contralateral parotid gland appears to correlated best with the clinical endpoints of severe/very severe dry mouth. An EQD2Gy dose of 21Gy appears to be a safe threshold to be used as a constraint in treatment planning.

Access to and Competition Between Airports: A Case Study for the San Francisco Bay Area

NARCIS (Netherlands)

Pels, E.; Nijkamp, P.; Rietveld, P.

2003-01-01

In this paper (nested) logit models that describe the combined access mode-airport-choice are estimated. A three level nested logit model is rejected. A two level nested logit model with the airport choice at the top level and the access mode choice at the lower level is preferred. From the

A dynamic random effects multinomial logit model of household car ownership

DEFF Research Database (Denmark)

Bue Bjørner, Thomas; Leth-Petersen, Søren

2007-01-01

Using a large household panel we estimate demand for car ownership by means of a dynamic multinomial model with correlated random effects. Results suggest that the persistence in car ownership observed in the data should be attributed to both true state dependence and to unobserved heterogeneity...... (random effects). It also appears that random effects related to single and multiple car ownership are correlated, suggesting that the IIA assumption employed in simple multinomial models of car ownership is invalid. Relatively small elasticities with respect to income and car costs are estimated...

Disposición a pagar por reducir el tiempo de viaje en Tunja (Colombia): Comparación entre estudiantes y trabajadores con un modelo Logit mixto

OpenAIRE

Luis Gabriel Márquez Díaz

2013-01-01

Resumen: El estudio analiza la diferencia en la disposición a pagar de estudiantes y trabajadores por reducir el tiempo de viaje, en un contexto de elección de modo de transporte para la ciudad de Tunja (Colombia). Se utilizó un modelo logit mixto, calibrado con datos provenientes de una encuesta de preferencias declaradas. La especificación del modelo supuso la variación aleatoria de los coeficientes del tiempo de acceso, tiempo de espera y tiempo de viaje. Se encontró que la disposición a p...

An integrated logit model for contamination event detection in water distribution systems.

Science.gov (United States)

Housh, Mashor; Ostfeld, Avi

2015-05-15

The problem of contamination event detection in water distribution systems has become one of the most challenging research topics in water distribution systems analysis. Current attempts for event detection utilize a variety of approaches including statistical, heuristics, machine learning, and optimization methods. Several existing event detection systems share a common feature in which alarms are obtained separately for each of the water quality indicators. Unifying those single alarms from different indicators is usually performed by means of simple heuristics. A salient feature of the current developed approach is using a statistically oriented model for discrete choice prediction which is estimated using the maximum likelihood method for integrating the single alarms. The discrete choice model is jointly calibrated with other components of the event detection system framework in a training data set using genetic algorithms. The fusing process of each indicator probabilities, which is left out of focus in many existing event detection system models, is confirmed to be a crucial part of the system which could be modelled by exploiting a discrete choice model for improving its performance. The developed methodology is tested on real water quality data, showing improved performances in decreasing the number of false positive alarms and in its ability to detect events with higher probabilities, compared to previous studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

A day in the city : using conjoint choice experiments to model urban tourists' choice of activity packages

NARCIS (Netherlands)

Dellaert, B.G.C.; Borgers, A.W.J.; Timmermans, H.J.P.

1995-01-01

This paper introduces and tests a conjoint choice experiment approach to modeling urban tourists' choice of activity packages. The joint logit model is introduced as a tool to model choices between combinations of activities and an experimental design approach is proposed that includes attributes

Assessing the value of museums with a combined discrete choice/ count data model

NARCIS (Netherlands)

Rouwendal, J.; Boter, J.

2009-01-01

This article assesses the value of Dutch museums using information about destination choice as well as about the number of trips undertaken by an actor. Destination choice is analysed by means of a mixed logit model, and a count data model is used to explain trip generation. We use a

TAFV Alternative Fuels and Vehicles Choice Model Documentation; TOPICAL

International Nuclear Information System (INIS)

Greene, D.L.

2001-01-01

A model for predicting choice of alternative fuel and among alternative vehicle technologies for light-duty motor vehicles is derived. The nested multinomial logit (NML) mathematical framework is used. Calibration of the model is based on information in the existing literature and deduction based on assuming a small number of key parameters, such as the value of time and discount rates. A spreadsheet model has been developed for calibration and preliminary testing of the model

Choice experiments versus revealed choice models : a before-after study of consumer spatial shopping behavior

NARCIS (Netherlands)

Timmermans, H.J.P.; Borgers, A.W.J.; Waerden, van der P.J.H.J.

1992-01-01

The purpose of this article is to compare a set of multinomial logit models derived from revealed choice data and a decompositional choice model derived from experimental data in terms of predictive success in the context of consumer spatial shopping behavior. Data on consumer shopping choice

Evaluation of Statistical Methods for Modeling Historical Resource Production and Forecasting

Science.gov (United States)

Nanzad, Bolorchimeg

This master's thesis project consists of two parts. Part I of the project compares modeling of historical resource production and forecasting of future production trends using the logit/probit transform advocated by Rutledge (2011) with conventional Hubbert curve fitting, using global coal production as a case study. The conventional Hubbert/Gaussian method fits a curve to historical production data whereas a logit/probit transform uses a linear fit to a subset of transformed production data. Within the errors and limitations inherent in this type of statistical modeling, these methods provide comparable results. That is, despite that apparent goodness-of-fit achievable using the Logit/Probit methodology, neither approach provides a significant advantage over the other in either explaining the observed data or in making future projections. For mature production regions, those that have already substantially passed peak production, results obtained by either method are closely comparable and reasonable, and estimates of ultimately recoverable resources obtained by either method are consistent with geologically estimated reserves. In contrast, for immature regions, estimates of ultimately recoverable resources generated by either of these alternative methods are unstable and thus, need to be used with caution. Although the logit/probit transform generates high quality-of-fit correspondence with historical production data, this approach provides no new information compared to conventional Gaussian or Hubbert-type models and may have the effect of masking the noise and/or instability in the data and the derived fits. In particular, production forecasts for immature or marginally mature production systems based on either method need to be regarded with considerable caution. Part II of the project investigates the utility of a novel alternative method for multicyclic Hubbert modeling tentatively termed "cycle-jumping" wherein overlap of multiple cycles is limited. The

A Smooth Transition Logit Model of the Effects of Deregulation in the Electricity Market

DEFF Research Database (Denmark)

Hurn, A.S.; Silvennoinen, Annastiina; Teräsvirta, Timo

We consider a nonlinear vector model called the logistic vector smooth transition autoregressive model. The bivariate single-transition vector smooth transition regression model of Camacho (2004) is generalised to a multivariate and multitransition one. A modelling strategy consisting of specific......We consider a nonlinear vector model called the logistic vector smooth transition autoregressive model. The bivariate single-transition vector smooth transition regression model of Camacho (2004) is generalised to a multivariate and multitransition one. A modelling strategy consisting...... of specification, including testing linearity, estimation and evaluation of these models is constructed. Nonlinear least squares estimation of the parameters of the model is discussed. Evaluation by misspecification tests is carried out using tests derived in a companion paper. The use of the modelling strategy...

Improving navigability on the Kromme River Estuary: A choice ...

African Journals Online (AJOL)

2013-03-14

Mar 14, 2013 ... logit model, random parameters logit model. INTRODUCTION .... tives, is treated by the RUM as a stochastic, utility-maximising choice (Louviere et ..... comparable to the one estimated for a linear regression model. (the ones ...

A joint model of mode and shipment size choice using the first generation of Commodity Flow Survey Public Use Microdata

Directory of Open Access Journals (Sweden)

Monique Stinson

2017-12-01

Full Text Available A behavior-based supply chain and freight transportation model was developed and implemented for the Maricopa Association of Governments (MAG and Pima Association of Governments (PAG. This innovative, data-driven modeling system simulates commodity flows to, from and within Phoenix and Tucson Megaregion and is used for regional planning purposes. This paper details the logistics choice component of the system and describes the position and functioning of this component in the overall framework. The logistics choice model uses a nested logit formulation to evaluate mode choice and shipment size jointly. Modeling decisions related to integrating this component within the overall framework are discussed. This paper also describes practical insights gained from using the 2012 Commodity Flow Survey Public Use Microdata (released in 2015, which was the principal data source used to estimate the joint shipment size-mode choice nested logit model. Finally, the validation effort and related lessons learned are described.

Random Coefficient Logit Model for Large Datasets

NARCIS (Netherlands)

C. Hernández-Mireles (Carlos); D. Fok (Dennis)

2010-01-01

textabstractWe present an approach for analyzing market shares and products price elasticities based on large datasets containing aggregate sales data for many products, several markets and for relatively long time periods. We consider the recently proposed Bayesian approach of Jiang et al [Jiang,

Loss given default models incorporating macroeconomic variables for credit cards

OpenAIRE

Crook, J.; Bellotti, T.

2012-01-01

Based on UK data for major retail credit cards, we build several models of Loss Given Default based on account level data, including Tobit, a decision tree model, a Beta and fractional logit transformation. We find that Ordinary Least Squares models with macroeconomic variables perform best for forecasting Loss Given Default at the account and portfolio levels on independent hold-out data sets. The inclusion of macroeconomic conditions in the model is important, since it provides a means to m...

A Passenger Travel Demand Model for Copenhagen

DEFF Research Database (Denmark)

Overgård, Christian Hansen; Jovicic, Goran

2003-01-01

The passenger travel model for Copenhagen is a state-of-practice nested logit model in which the sub-models - i.e. generation, distribution and mode choice models - are connected via measure of accessibility. The model includes in its structure a large set of explanatory variables at all three...... aims to provide a detailed description of the model, which can be used as a guide to the future development of similar models. Also, an application of the model in a study of road pricing in denmark is described. This gives the reader an idea of how such a policy measure can be modelled as well...

Area Based Models of New Highway Route Growth

OpenAIRE

David Levinson; Wei Chen

2007-01-01

Empirical data and statistical models are used to answer the question of where new highway routes are most likely to be located. High-quality land-use, population distribution and highway network GIS data for the Twin CitiesMetropolitan Area from 1958 to 1990 are developed for this study. The highway system is classified into three levels, Interstate highways, divided highways, and secondary highways. Binary logit models estimate the new route growth probability of divided highways and second...

Modeling Intercity Mode Choice and Airport Choice in the United States

OpenAIRE

Ashiabor, Senanu Y.

2007-01-01

The aim of this study was to develop a framework to model travel choice behavior in order to estimate intercity travel demand at nation-level in the United States. Nested and mixed logit models were developed to study national-level intercity transportation in the United States. A separate General Aviation airport choice model to estimates General Aviation person-trips and number of aircraft operations though more than 3000 airports was also developed. The combination of the General Aviati...

A smooth transition logit model of the effects of deregulation in the electricity market

DEFF Research Database (Denmark)

Hurn, A. Stan; Silvennoinen, Annastiina; Teräsvirta, Timo

2016-01-01

of the model are derived along with their asymptotic properties, together with a Lagrange multiplier test of the null hypothesis of linearity in the underlying latent index. The development of the STL model is motivated by the desire to assess the impact of deregulation in the Queensland electricity market...... and ascertain whether increased competition has resulted in significant changes in the behaviour of the spot price of electricity, specifically with respect to the occurrence of periodic abnormally high prices. The model allows the timing of any change to be endogenously determined and also market participants...

Analysis of transtheoretical model of health behavioral changes in a nutrition intervention study--a continuous time Markov chain model with Bayesian approach.

Science.gov (United States)

Ma, Junsheng; Chan, Wenyaw; Tsai, Chu-Lin; Xiong, Momiao; Tilley, Barbara C

2015-11-30

Continuous time Markov chain (CTMC) models are often used to study the progression of chronic diseases in medical research but rarely applied to studies of the process of behavioral change. In studies of interventions to modify behaviors, a widely used psychosocial model is based on the transtheoretical model that often has more than three states (representing stages of change) and conceptually permits all possible instantaneous transitions. Very little attention is given to the study of the relationships between a CTMC model and associated covariates under the framework of transtheoretical model. We developed a Bayesian approach to evaluate the covariate effects on a CTMC model through a log-linear regression link. A simulation study of this approach showed that model parameters were accurately and precisely estimated. We analyzed an existing data set on stages of change in dietary intake from the Next Step Trial using the proposed method and the generalized multinomial logit model. We found that the generalized multinomial logit model was not suitable for these data because it ignores the unbalanced data structure and temporal correlation between successive measurements. Our analysis not only confirms that the nutrition intervention was effective but also provides information on how the intervention affected the transitions among the stages of change. We found that, compared with the control group, subjects in the intervention group, on average, spent substantively less time in the precontemplation stage and were more/less likely to move from an unhealthy/healthy state to a healthy/unhealthy state. Copyright © 2015 John Wiley & Sons, Ltd.

A three-parameter langmuir-type model for fitting standard curves of sandwich enzyme immunoassays with special attention to the α-fetoprotein assay

NARCIS (Netherlands)

Kortlandt, W.; Endeman, H.J.; Hoeke, J.O.O.

In a simplified approach to the reaction kinetics of enzyme-linked immunoassays, a Langmuir-type equation y = [ax/(b + x)] + c was derived. This model proved to be superior to logit-log and semilog models in the curve-fitting of standard curves. An assay for α-fetoprotein developed in our laboratory

Modeling individual and collective opinion in online social networks: drivers of choice behavior and effects of marketing interventions

NARCIS (Netherlands)

Koster, S.E.; Langley, D.J.

2013-01-01

We investigate factors influencing choice behavior in online social networks. We use twitter data from a Dutch television talent show. In study one, we implement a nested conditional logit model with latent classes. We find heterogeneous effects. For two latent classes, cognitive factors most

Airport terminal choice model

Directory of Open Access Journals (Sweden)

Claudia Helena Muñoz-Hoyos

2014-01-01

Full Text Available La mayoría de los estudios del modo aéreo han tratado individua lmente los aspectos de tarifas, demoras y demás variables inher entes a este medio de transporte, así como la elección del modo aéreo f rente a otros modos, pero poco se ha hecho por modelar cómo un viajero elige un aeropuerto entre dos opciones disponibles en una gran ciudad. En la actualidad un pasajero que parte de la ciudad de Medellín - Colombia a algunos destinos nacionales, tiene la opción de v iajar por alguno de los dos aeropuertos, el José María Córdova (JMC o el Enriqu e Olaya Herrera (EOH; esta investigación presenta los resultad os de una encuesta de preferencias declaradas en un experimento de elecci ón discreta, y partiendo de esto se obtiene un modelo por desti no; para cada uno de estos se hallaron modelos logit multinomial y logit mixt o; en cada trayecto evaluado se eligió el logit multinomial com o el mejor.

Modeling the Choice of Telecommuting Frequency in California: An Exploratory Analysis

OpenAIRE

Mannering, Jill S.; Mokhtarian, Patricia L.

1995-01-01

This study explores the individual's choice of telecommuting frequency as a function of demographic, travel, work and attitudinal factors. To do this, multinomial logit models are estimated using data collected in a recent survey of employees from three public agencies in California. Separate models are estimated, one for data collected from the Franchise Tax Board in Sacramento, one for data from the Public Utilities Commission in San Francisco, and one for data collected from employees of t...

Examination of heterogeneous societies: Identifying subpopulations by contrasting cultures

DEFF Research Database (Denmark)

Glückstad, Fumiko Kano; Schmidt, Mikkel Nørgaard; Mørup, Morten

2017-01-01

, the infinite relational model (IRM) is a new and disruptive type of unsupervised clustering approach that has been developed recently by cognitive psychologists and computer scientists. In this article, an extended version of the IRM coined the multinominal IRM—or mIRM in short—is applied to a cross......-cultural analysis of survey data available from the World Value Survey organization. Specifically, the present work analyzes response patterns of the Portrait Value Questionnaire (PVQ) representing Schwartz’s 10 basic values of Japanese and Swedes. The applied model exposes heterogeneous structures of the two...

Modeling route choice criteria from home to major streets: A discrete choice approach

Directory of Open Access Journals (Sweden)

Jose Osiris Vidana-Bencomo

2018-03-01

Full Text Available A discrete choice model that consists of three sub-models was developed to investigates the route choice criteria of drivers who travel from their homes in the morning to the access point along the major streets that bound the Traffic Analysis Zones (TAZs. The first sub-model is a Nested Logit Model (NLM that estimates the probability of a driver has or has no multiple routes, and if the driver has multiple routes, the route selection criteria are based on the access point’s intersection control type or other factors. The second sub-model is a Mixed Logit (MXL model. It estimates the probabilities of the type of intersection control preferred by a driver. The third sub-model is a NLM that estimates the probabilities of a driver selecting his/her route for its shortest travel time or to avoid pedestrian, and if the aim is to take the fastest route, the decision criteria is based on the shortest distance or minimum stops and turns. Data gathered in a questionnaire survey were used to estimate the sub-models. The attributes of the utility functions of the sub-models are the driver’s demographic and trip characteristics. The model provides a means for transportation planners to distribute the total number of home-based trips generated within a TAZ to the access points along the major streets that bound the TAZ.

Construction of risk prediction model of type 2 diabetes mellitus based on logistic regression

Directory of Open Access Journals (Sweden)

Li Jian

2017-01-01

Full Text Available Objective: to construct multi factor prediction model for the individual risk of T2DM, and to explore new ideas for early warning, prevention and personalized health services for T2DM. Methods: using logistic regression techniques to screen the risk factors for T2DM and construct the risk prediction model of T2DM. Results: Male’s risk prediction model logistic regression equation: logit(P=BMI × 0.735+ vegetables × (−0.671 + age × 0.838+ diastolic pressure × 0.296+ physical activity× (−2.287 + sleep ×(−0.009 +smoking ×0.214; Female’s risk prediction model logistic regression equation: logit(P=BMI ×1.979+ vegetables× (−0.292 + age × 1.355+ diastolic pressure× 0.522+ physical activity × (−2.287 + sleep × (−0.010.The area under the ROC curve of male was 0.83, the sensitivity was 0.72, the specificity was 0.86, the area under the ROC curve of female was 0.84, the sensitivity was 0.75, the specificity was 0.90. Conclusion: This study model data is from a compared study of nested case, the risk prediction model has been established by using the more mature logistic regression techniques, and the model is higher predictive sensitivity, specificity and stability.

Modelling the spatio-temporal distribution of age-1 bay of biscay anchovy (Engraulis encrasicolus) at spawning time [Distribución espacio-temporal de la edad 1 de anchoa del golfo de Bizkaia (Engraulis Encrasicolus) en el momento de puesta

KAUST Repository

Ibaibarriaga, Leire; Uriarte, André s; Laconcha, Urtzi; Bernal, Miguel C.; Begoñ a Santos, Maria; Chifflet, Marina; Irigoien, Xabier

2013-01-01

during the main spawning period based on adult samples from 15 daily egg production method surveys. The proportion of age-1 individuals was modelled using generalized additive models with a binomial distribution and a logit link in relation

Correlations and Non-Linear Probability Models

DEFF Research Database (Denmark)

Breen, Richard; Holm, Anders; Karlson, Kristian Bernt

2014-01-01

the dependent variable of the latent variable model and its predictor variables. We show how this correlation can be derived from the parameters of non-linear probability models, develop tests for the statistical significance of the derived correlation, and illustrate its usefulness in two applications. Under......Although the parameters of logit and probit and other non-linear probability models are often explained and interpreted in relation to the regression coefficients of an underlying linear latent variable model, we argue that they may also be usefully interpreted in terms of the correlations between...... certain circumstances, which we explain, the derived correlation provides a way of overcoming the problems inherent in cross-sample comparisons of the parameters of non-linear probability models....

Modeling a Multinomial Logit Model of Intercity Travel Mode Choice Behavior for All Trips in Libya

OpenAIRE

Manssour A. Abdulsalam Bin Miskeen; Ahmed Mohamed Alhodairi; Riza Atiq Abdullah Bin O. K. Rahmat

2013-01-01

In the planning point of view, it is essential to have mode choice, due to the massive amount of incurred in transportation systems. The intercity travellers in Libya have distinct features, as against travellers from other countries, which includes cultural and socioeconomic factors. Consequently, the goal of this study is to recognize the behavior of intercity travel using disaggregate models, for projecting the demand of nation-level intercity travel in Libya. Multinom...

ADOPT: A Historically Validated Light Duty Vehicle Consumer Choice Model

Energy Technology Data Exchange (ETDEWEB)

Brooker, A.; Gonder, J.; Lopp, S.; Ward, J.

2015-05-04

The Automotive Deployment Option Projection Tool (ADOPT) is a light-duty vehicle consumer choice and stock model supported by the U.S. Department of Energy’s Vehicle Technologies Office. It estimates technology improvement impacts on U.S. light-duty vehicles sales, petroleum use, and greenhouse gas emissions. ADOPT uses techniques from the multinomial logit method and the mixed logit method estimate sales. Specifically, it estimates sales based on the weighted value of key attributes including vehicle price, fuel cost, acceleration, range and usable volume. The average importance of several attributes changes nonlinearly across its range and changes with income. For several attributes, a distribution of importance around the average value is used to represent consumer heterogeneity. The majority of existing vehicle makes, models, and trims are included to fully represent the market. The Corporate Average Fuel Economy regulations are enforced. The sales feed into the ADOPT stock model. It captures key aspects for summing petroleum use and greenhouse gas emissions This includes capturing the change in vehicle miles traveled by vehicle age, the creation of new model options based on the success of existing vehicles, new vehicle option introduction rate limits, and survival rates by vehicle age. ADOPT has been extensively validated with historical sales data. It matches in key dimensions including sales by fuel economy, acceleration, price, vehicle size class, and powertrain across multiple years. A graphical user interface provides easy and efficient use. It manages the inputs, simulation, and results.

Gaussian Process Regression Model in Spatial Logistic Regression

Science.gov (United States)

Sofro, A.; Oktaviarina, A.

2018-01-01

Spatial analysis has developed very quickly in the last decade. One of the favorite approaches is based on the neighbourhood of the region. Unfortunately, there are some limitations such as difficulty in prediction. Therefore, we offer Gaussian process regression (GPR) to accommodate the issue. In this paper, we will focus on spatial modeling with GPR for binomial data with logit link function. The performance of the model will be investigated. We will discuss the inference of how to estimate the parameters and hyper-parameters and to predict as well. Furthermore, simulation studies will be explained in the last section.

Examining Pedestrian Injury Severity Using Alternative Disaggregate Models

DEFF Research Database (Denmark)

Abay, Kibrom Araya

2013-01-01

This paper investigates the injury severity of pedestrians considering detailed road user characteristics and alternative model specification using a high-quality Danish road accident data. Such detailed and alternative modeling approach helps to assess the sensitivity of empirical inferences...... to the choice of these models. The empirical analysis reveals that detailed road user characteristics such as crime history of drivers and momentary activities of road users at the time of the accident provides an interesting insight in the injury severity analysis. Likewise, the alternative analytical...... specification of the models reveals that some of the conventionally employed fixed parameters injury severity models could underestimate the effect of some important behavioral attributes of the accidents. For instance, the standard ordered logit model underestimated the marginal effects of some...

An integrated model to simulate sown area changes for major crops at a global scale

Institute of Scientific and Technical Information of China (English)

SHIBASAKI; Ryosuke

2008-01-01

Dynamics of land use systems have attracted much attention from scientists around the world due to their ecological and socio-economic implications. An integrated model to dynamically simulate future changes in sown areas of four major crops (rice, maize, wheat and soybean) on a global scale is pre- sented. To do so, a crop choice model was developed on the basis of Multinomial Logit (Logit) model to model land users’ decisions on crop choices among a set of available alternatives with using a crop utility function. A GIS-based Environmental Policy Integrated Climate (EPIC) model was adopted to simulate the crop yields under a given geophysical environment and farming management conditions, while the International Food Policy and Agricultural Simulation (IFPSIM) model was utilized to estimate crop price in the international market. The crop choice model was linked with the GIS-based EPIC model and the IFPSIM model through data exchange. This integrated model was then validated against the FAO statistical data in 2001-2003 and the Moderate Resolution Imaging Spectroradiometer (MODIS) global land cover product in 2001. Both validation approaches indicated reliability of the model for ad- dressing the dynamics in agricultural land use and its capability for long-term scenario analysis. Finally, the model application was designed to run over a time period of 30 a, taking the year 2000 as baseline. The model outcomes can help understand and explain the causes, locations and consequences of land use changes, and provide support for land use planning and policy making.

An integrated model to simulate sown area changes for major crops at a global scale

Institute of Scientific and Technical Information of China (English)

WU WenBin; YANG Peng; MENG ChaoYing; SHIBASAKI Ryosuke; ZHOU QingBo; TANG HuaJun; SHI Yun

2008-01-01

Dynamics of land use systems have attracted much attention from scientists around the world due to their ecological and socio-economic implications. An integrated model to dynamically simulate future changes in sown areas of four major crops (rice, maize, wheat and soybean) on a global scale is presented. To do so, a crop choice model was developed on the basis of Multinomial Logit (Logit) model to model land users' decisions on crop choices among a set of available alternatives with using a crop utility function. A GIS-based Environmental Policy Integrated Climate (EPIC) model was adopted to simulate the crop yields under a given geophysical environment and farming management conditions,while the International Food Policy and Agricultural Simulation (IFPSIM) model was utilized to estimate crop price in the international market. The crop choice model was linked with the GIS-based EPIC model and the IFPSIM model through data exchange. This integrated model was then validated against the FAO statistical data in 2001-2003 and the Moderate Resolution Imaging Spectroradiometer (MODIS)global land cover product in 2001. Both validation approaches indicated reliability of the model for addressing the dynamics in agricultural land use and its capability for long-term scenario analysis. Finally,the model application was designed to run over a time period of 30 a, taking the year 2000 as baseline.The model outcomes can help understand and explain the causes, locations and consequences of land use changes, and provide support for land use planning and policy making.

Cognitive overload? An exploration of the potential impact of cognitive functioning in discrete choice experiments with older people in health care.

Science.gov (United States)

Milte, Rachel; Ratcliffe, Julie; Chen, Gang; Lancsar, Emily; Miller, Michelle; Crotty, Maria

2014-07-01

This exploratory study sought to investigate the effect of cognitive functioning on the consistency of individual responses to a discrete choice experiment (DCE) study conducted exclusively with older people. A DCE to investigate preferences for multidisciplinary rehabilitation was administered to a consenting sample of older patients (aged 65 years and older) after surgery to repair a fractured hip (N = 84). Conditional logit, mixed logit, heteroscedastic conditional logit, and generalized multinomial logit regression models were used to analyze the DCE data and to explore the relationship between the level of cognitive functioning (specifically the absence or presence of mild cognitive impairment as assessed by the Mini-Mental State Examination) and preference and scale heterogeneity. Both the heteroscedastic conditional logit and generalized multinomial logit models indicated that the presence of mild cognitive impairment did not have a significant effect on the consistency of responses to the DCE. This study provides important preliminary evidence relating to the effect of mild cognitive impairment on DCE responses for older people. It is important that further research be conducted in larger samples and more diverse populations to further substantiate the findings from this exploratory study and to assess the practicality and validity of the DCE approach with populations of older people. Copyright © 2014 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Seroprevalence of brucellosis among women with miscarriage at ...

African Journals Online (AJOL)

manufactured by Diagnostic automation, Incorporated, ... This Diagnostic Automation's Brucella. IgM and ... Multi-nominal logistic regression analyses showed that .... Business. 2 (1.7%). 2 (1.7%). Civil service. 2 (1.7%). Housewife. 13 (10.7%).

Centile estimation for a proportion response variable.

Science.gov (United States)

Hossain, Abu; Rigby, Robert; Stasinopoulos, Mikis; Enea, Marco

2016-03-15

This paper introduces two general models for computing centiles when the response variable Y can take values between 0 and 1, inclusive of 0 or 1. The models developed are more flexible alternatives to the beta inflated distribution. The first proposed model employs a flexible four parameter logit skew Student t (logitSST) distribution to model the response variable Y on the unit interval (0, 1), excluding 0 and 1. This model is then extended to the inflated logitSST distribution for Y on the unit interval, including 1. The second model developed in this paper is a generalised Tobit model for Y on the unit interval, including 1. Applying these two models to (1-Y) rather than Y enables modelling of Y on the unit interval including 0 rather than 1. An application of the new models to real data shows that they can provide superior fits. Copyright © 2015 John Wiley & Sons, Ltd.

Three essays on resource economics. Demand systems for energy forecasting: Practical considerations for estimating a generalized logit model, To borrow or not to borrow: A variation on the MacDougal-Kemp theme, and, Valuing reduced risk for households with children or the retired

Science.gov (United States)

Weng, Weifeng

This thesis presents papers on three areas of study within resource and environmental economics. "Demand Systems For Energy Forecasting" provides some practical considerations for estimating a Generalized Logit model. The main reason for using this demand system for energy and other factors is that the derived price elasticities are robust when expenditure shares are small. The primary objective of the paper is to determine the best form of the cross-price weights, and a simple inverse function of the expenditure share is selected. A second objective is to demonstrate that the estimated elasticities are sensitive to the units specified for the prices, and to show how price scales can be estimated as part of the model. "To Borrow or Not to Borrow: A Variation on the MacDougal-Kemp Theme" studies the impact of international capital movements on the conditional convergence of economies differing from each other only in initial wealth. We found that in assets, income, consumption and utility, convergence obtains, with and only with, the absence of international capital movement. When a rich country invests in a poor country, the balance of debt increases forever. Asset ownership is increased in all periods for the lender, and asset ownership of the borrower is deceased. Also, capital investment decreases the lender's utility for early periods, but increases it forever after a cross-over point. In contrast, the borrower's utility increases for early periods, but then decreases forever. "Valuing Reduced Risk for Households with Children or the Retired" presents a theoretical model of how families value risk and then exams family automobile purchases to impute the average Value of a Statistical Life (VSL) for each type of family. Data for fatal accidents are used to estimate survival rates for individuals in different types of accidents, and the probabilities of having accidents for different types of vehicle. These models are used to determine standardized risks for

A dynamic programming approach for quickly estimating large network-based MEV models

DEFF Research Database (Denmark)

Mai, Tien; Frejinger, Emma; Fosgerau, Mogens

2017-01-01

We propose a way to estimate a family of static Multivariate Extreme Value (MEV) models with large choice sets in short computational time. The resulting model is also straightforward and fast to use for prediction. Following Daly and Bierlaire (2006), the correlation structure is defined by a ro...... to converge (4.3 h on an Intel(R) 3.2 GHz machine using a non-parallelized code). We also show that our approach allows to estimate a cross-nested logit model of 111 nests with a real data set of more than 100,000 observations in 14 h....

Modeling the Joint Labor-Commute Engagement Decisions of San Francisco Bay Area Residents

OpenAIRE

Ory, David T.; Mokhtarian, Patricia L.

2005-01-01

Using socio-demographic, personality, and attitudinal data from 1,680 residents of the San Francisco Bay Area, we develop and estimate binary, multinomial, and nested logit models of the choice to work or not, whether or not to work at home, and whether to commute all of the time or some of the time (either by only working part time, or by working a compressed work week, or by telecommuting some of the time). To our knowledge, these are the first models of all these choices simultaneously. Th...

An Evaluation of Parametric and Nonparametric Models of Fish Population Response.

Energy Technology Data Exchange (ETDEWEB)

Haas, Timothy C.; Peterson, James T.; Lee, Danny C.

1999-11-01

Predicting the distribution or status of animal populations at large scales often requires the use of broad-scale information describing landforms, climate, vegetation, etc. These data, however, often consist of mixtures of continuous and categorical covariates and nonmultiplicative interactions among covariates, complicating statistical analyses. Using data from the interior Columbia River Basin, USA, we compared four methods for predicting the distribution of seven salmonid taxa using landscape information. Subwatersheds (mean size, 7800 ha) were characterized using a set of 12 covariates describing physiography, vegetation, and current land-use. The techniques included generalized logit modeling, classification trees, a nearest neighbor technique, and a modular neural network. We evaluated model performance using out-of-sample prediction accuracy via leave-one-out cross-validation and introduce a computer-intensive Monte Carlo hypothesis testing approach for examining the statistical significance of landscape covariates with the non-parametric methods. We found the modular neural network and the nearest-neighbor techniques to be the most accurate, but were difficult to summarize in ways that provided ecological insight. The modular neural network also required the most extensive computer resources for model fitting and hypothesis testing. The generalized logit models were readily interpretable, but were the least accurate, possibly due to nonlinear relationships and nonmultiplicative interactions among covariates. Substantial overlap among the statistically significant (P<0.05) covariates for each method suggested that each is capable of detecting similar relationships between responses and covariates. Consequently, we believe that employing one or more methods may provide greater biological insight without sacrificing prediction accuracy.

Choice Model and Influencing Factor Analysis of Travel Mode for Migrant Workers: Case Study in Xi’an, China

OpenAIRE

Hong Chen; Zuo-xian Gan; Yu-ting He

2015-01-01

Based on the basic theory and methods of disaggregate choice model, the influencing factors in travel mode choice for migrant workers are analyzed, according to 1366 data samples of Xi’an migrant workers. Walking, bus, subway, and taxi are taken as the alternative parts of travel modes for migrant workers, and a multinomial logit (MNL) model of travel mode for migrant workers is set up. The validity of the model is verified by the hit rate, and the hit rates of four travel modes are all great...

Attitudinal travel demand model for non-work trips of homogeneously constrained segments of a population

Energy Technology Data Exchange (ETDEWEB)

Recker, W.W.; Stevens, R.F.

1977-06-01

Market-segmentation techniques are used to capture effects of opportunity and availability constraints on urban residents' choice of mode for trips for major grocery shopping and for visiting friends and acquaintances. Attitudinal multinomial logit choice models are estimated for each market segment. Explanatory variables are individual's beliefs about attributes of four modal alternatives: bus, car, taxi and walking. Factor analysis is employed to identify latent dimensions of perception of the modal alternatives and to eliminate problems of multicollinearity in model estimation.

A Model of Bus Bunching under Reliability-based Passenger Arrival Patterns

OpenAIRE

Fonzone, Achille; Schmöcker, Jan-Dirk; Liu, Ronghui

2015-01-01

If bus service departure times are not completely unknown to the passengers, non-uniform passenger arrival patterns can be expected. We propose that passengers decide their arrival time at stops based on a continuous logit model that considers the risk of missing services. Expected passenger waiting times are derived in a bus system that allows also for overtaking between bus services. We then propose an algorithm to derive the dwell time of subsequent buses serving a stop in order to illustr...

A COUNTY-LEVEL MODEL OF MANUFACTURING PLANT RECRUITMENT WITH IMPROVED INDUSTRIAL SITE QUALITY MEASUREMENT

OpenAIRE

Kriesel, Warren; McNamara, Kevin T.

1991-01-01

Empirical analysis of manufacturing plant location requires the use of a single industrial site quality measure. Under hedonic price theory, the price of industrial sites can be explained by their quality characteristics. The estimated site price is included with ten other location factors in an ordered, categorical logit model of plant attraction to Georgia counties. The results inform public decision-makers of the relative impact of site location factors and how changes in location factors ...

Disposición a pagar por reducir el tiempo de viaje en Tunja (Colombia: Comparación entre estudiantes y trabajadores con un modelo Logit mixto

Directory of Open Access Journals (Sweden)

Luis Gabriel Marquez Diaz

2013-01-01

Full Text Available Resumen: El estudio analiza la diferencia en la disposición a pagar de estudiantes y trabajadores por reducir el tiempo de viaje, en un contexto de elección de modo de transporte para la ciudad de Tunja (Colombia. Se utilizó un modelo logit mixto, calibrado con datos provenientes de una encuesta de preferencias declaradas. La especificación del modelo supuso la variación aleatoria de los coeficientes del tiempo de acceso, tiempo de espera y tiempo de viaje. Se encontró que la disposición a pagar por reducir el tiempo de viaje es de 38.14 $/min para estudiantes, siendo 23% mayor para trabajadores de menor ingreso y 73% mayor para los trabajadores de mayor ingreso. Se determinó que el valor del tiempo de espera es 1.95 veces mayor que el tiempo viaje, en tanto que el tiempo de acceso mantiene una relación de 1 a 2.57 con respecto al tiempo de viaje, la cual se considera válida únicamente para el contexto estudiado.

Road traffic noise: self-reported noise annoyance versus GIS modelled road traffic noise exposure.

Science.gov (United States)

Birk, Matthias; Ivina, Olga; von Klot, Stephanie; Babisch, Wolfgang; Heinrich, Joachim

2011-11-01

self-reported road traffic noise annoyance is commonly used in epidemiological studies for assessment of potential health effects. Alternatively, some studies have used geographic information system (GIS) modelled exposure to road traffic noise as an objective parameter. The aim of this study was to analyse the association between noise exposure due to neighbouring road traffic and the noise annoyance of adults, taking other determinants into consideration. parents of 951 Munich children from the two German birth cohorts GINIplus and LISAplus reported their annoyance due to road traffic noise at home. GIS modelled road traffic noise exposure (L(den), maximum within a 50 m buffer) from the noise map of the city of Munich was available for all families. GIS-based calculated distance to the closest major road (≥10,000 vehicles per day) and questionnaire based-information about family income, parental education and the type of the street of residence were explored for their potential influence. An ordered logit regression model was applied. The noise levels (L(den)) and the reported noise annoyance were compared with an established exposure-response function. the correlation between noise annoyance and noise exposure (L(den)) was fair (Spearman correlation r(s) = 0.37). The distance to a major road and the type of street were strong predictors for the noise annoyance. The annoyance modelled by the established exposure-response function and that estimated by the ordered logit model were moderately associated (Pearson's correlation r(p) = 0.50). road traffic noise annoyance was associated with GIS modelled neighbouring road traffic noise exposure (L(den)). The distance to a major road and the type of street were additional explanatory factors of the noise annoyance appraisal.

Estimation of social value of statistical life using willingness-to-pay method in Nanjing, China.

Science.gov (United States)

Yang, Zhao; Liu, Pan; Xu, Xin

2016-10-01

Rational decision making regarding the safety related investment programs greatly depends on the economic valuation of traffic crashes. The primary objective of this study was to estimate the social value of statistical life in the city of Nanjing in China. A stated preference survey was conducted to investigate travelers' willingness to pay for traffic risk reduction. Face-to-face interviews were conducted at stations, shopping centers, schools, and parks in different districts in the urban area of Nanjing. The respondents were categorized into two groups, including motorists and non-motorists. Both the binary logit model and mixed logit model were developed for the two groups of people. The results revealed that the mixed logit model is superior to the fixed coefficient binary logit model. The factors that significantly affect people's willingness to pay for risk reduction include income, education, gender, age, drive age (for motorists), occupation, whether the charged fees were used to improve private vehicle equipment (for motorists), reduction in fatality rate, and change in travel cost. The Monte Carlo simulation method was used to generate the distribution of value of statistical life (VSL). Based on the mixed logit model, the VSL had a mean value of 3,729,493 RMB ($586,610) with a standard deviation of 2,181,592 RMB ($343,142) for motorists; and a mean of 3,281,283 RMB ($505,318) with a standard deviation of 2,376,975 RMB ($366,054) for non-motorists. Using the tax system to illustrate the contribution of different income groups to social funds, the social value of statistical life was estimated. The average social value of statistical life was found to be 7,184,406 RMB ($1,130,032). Copyright © 2016 Elsevier Ltd. All rights reserved.

A long-distance travel demand model for Europe

DEFF Research Database (Denmark)

Rich, Jeppe; Mabit, Stefan Lindhard

2012-01-01

of different level-of-service variables. The results suggest that the perception of both travel time and cost varies with journey length in a non-linear way. For car drivers and car passengers, elasticities increase with the length of the journey, whereas the opposite is true for rail, bus, and air passengers...... relevant from a political and environmental point of view. The paper presents the first tour-based long-distance travel demand model for passenger trips in and between 42 European countries. The model is part of a new European transport model developed for the European Commission, the TRANSTOOLS II model......, and will serve as an important tool for transport policy analysis at a European level. The model is formulated as a nested logit model and estimated based on travel diary data with segmentation into business, private, and holiday trips. We analyse the estimation results and present elasticities for a number...

Logit Analysis for Profit Maximizing Loan Classification

OpenAIRE

Watt, David L.; Mortensen, Timothy L.; Leistritz, F. Larry

1988-01-01

Lending criteria and loan classification methods are developed. Rating system breaking points are analyzed to present a method to maximize loan revenues. Financial characteristics of farmers are used as determinants of delinquency in a multivariate logistic model. Results indicate that debt-to-asset and operating ration are most indicative of default.

Modelling Gender Differences in the Economic and Social Influences of Obesity in Australian Young People

OpenAIRE

Gulay Avsar; Roger Ham; W. Kathy Tannous

2017-01-01

In Australia, as in many other developed economies, the prevalence of obesity has risen significantly in all age groups and especially in young males and females over the past decade. Using data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey, this paper investigates the influence of economic, personality and social factor demographics on the incidence of obesity in Australian youths. The study uses two random parameters logit models, including one that allows for g...

A real-time crash prediction model for the ramp vicinities of urban expressways

Directory of Open Access Journals (Sweden)

Moinul Hossain

2013-07-01

Full Text Available Ramp vicinities are arguably the known black-spots on urban expressways. There, while maintaining high speed, drivers need to respond to several complex events such as maneuvering, reading road signs, route planning and maintaining safe distance from other maneuvering vehicles simultaneously which demand higher level of cognitive response to ensure safety. Therefore, any additional discomfort caused by traffic dynamics may induce driving error resulting in a crash. This manuscript presents a methodology for identifying these dynamically forming hazardous traffic conditions near the ramp vicinities with high resolution real-time traffic flow data. It separates the ramp vicinities into four zones – upstream and downstream of entrance and exit ramps, and builds four separate real-time crash prediction models. Around two year (December 2007 to October 2009 crash data as well as their matching traffic sensor data from Shibuya 3 and Shinjuku 4 expressways under the jurisdiction of Tokyo Metropolitan Expressway Company Limited have been utilized for this research. Random multinomial logit, a forest of multinomial logit models, has been used to identify the most important variables. Finally, a real-time modeling method, Bayesian belief net (BBN, has been employed to build the four models using ramp flow, flow and congestion index in the upstream and flow and speed in the downstream of the ramp location as variables. The newly proposed models could predict 50%, 42%, 43% and 55% of the future crashes with around 10% false alarm for the downstream of entrance, downstream of exit, upstream of entrance and upstream of exit ramps respectively. The models can be utilized in combination with various traffic smoothing measures such as ramp metering, variable speed limit, warning messages through variable message signs, etc. to enhance safety near the ramp vicinities.

SU-F-T-104: Determining the NTCP Parameters of Pharyngeal Constrictors and Proximal Esophagus for Radiation Induced Swallowing Problems Recorded Six Months After Radiation Therapy for Head and Neck Tumors

Energy Technology Data Exchange (ETDEWEB)

Mavroidis, P; Price, A; Kostich, M; Green, R; Das, S; Marks, L; Chera, B [University North Carolina, Chapel Hill, NC (United States); Amdur, R; Mendenhall, W [University of Florida, Gainesville, FL (United States); Sheets, N [University of North Carolina, Raleigh, NC (United States)

2016-06-15

Purpose: To estimate the radiobiological parameters of four NTCP models that describe the dose-response relations of pharyngeal constrictors and proximal esophagus regarding the severity of patient reported swallowing problems 6 months post chemo-radiotherapy. To identify the section/structure that best correlates with the manifestation of the clinical endpoints. Finally, to compare the goodness-of-fit of those models. Methods: Forty-three patients were treated on a prospective multi-institutional phase II study for oropharyngeal squamous cell carcinoma. All the patients received 60 Gy IMRT and they reported symptoms using the novel patient reported outcome version of the CTCAE. We derived the individual patient dosimetric data of superior, medium and inferior sections of pharyngeal constrictors (SPC, MPC and IPC), superior and inferior sections of esophagus (SES and IES) as separate structures as well as combinations. The Lyman-Kutcher-Burman (LKB), Relative Seriality (RS), Logit and Relative Logit (RL) NTCP models were used to fit the patient data. The fitting of the different models was assessed through the area under the receiver operating characteristic curve (AUC) and the Odds Ratio methods. Results: The AUC values were highest for the SPC for Grade ≥ 2 (0.719 for the RS and RL models, and 0.716 for LKB and Logit). For Grade ≥ 1, the respective values were 0.699 for RS, LKB and Logit and 0.676 for RL. For MPC the AUC values varied between 0.463–0.477, for IPC between 0.396–0.458, for SES between 0.556–0.613 and for IES between 0.410–0.519. The Odds Ratio for the SPC was 15.6 (1.7–146.4) for RS, LKB and Logit for NTCP of 55%. Conclusion: All the examined NTCP models could fit the clinical data with similar accuracy. The SPC appear to correlate best with the clinical endpoints of swallowing problems. A prospective study could establish the use of NTCP values of SPC as a constraint in treatment planning.

[Logistic regression model of noninvasive prediction for portal hypertensive gastropathy in patients with hepatitis B associated cirrhosis].

Science.gov (United States)

Wang, Qingliang; Li, Xiaojie; Hu, Kunpeng; Zhao, Kun; Yang, Peisheng; Liu, Bo

2015-05-12

To explore the risk factors of portal hypertensive gastropathy (PHG) in patients with hepatitis B associated cirrhosis and establish a Logistic regression model of noninvasive prediction. The clinical data of 234 hospitalized patients with hepatitis B associated cirrhosis from March 2012 to March 2014 were analyzed retrospectively. The dependent variable was the occurrence of PHG while the independent variables were screened by binary Logistic analysis. Multivariate Logistic regression was used for further analysis of significant noninvasive independent variables. Logistic regression model was established and odds ratio was calculated for each factor. The accuracy, sensitivity and specificity of model were evaluated by the curve of receiver operating characteristic (ROC). According to univariate Logistic regression, the risk factors included hepatic dysfunction, albumin (ALB), bilirubin (TB), prothrombin time (PT), platelet (PLT), white blood cell (WBC), portal vein diameter, spleen index, splenic vein diameter, diameter ratio, PLT to spleen volume ratio, esophageal varices (EV) and gastric varices (GV). Multivariate analysis showed that hepatic dysfunction (X1), TB (X2), PLT (X3) and splenic vein diameter (X4) were the major occurring factors for PHG. The established regression model was Logit P=-2.667+2.186X1-2.167X2+0.725X3+0.976X4. The accuracy of model for PHG was 79.1% with a sensitivity of 77.2% and a specificity of 80.8%. Hepatic dysfunction, TB, PLT and splenic vein diameter are risk factors for PHG and the noninvasive predicted Logistic regression model was Logit P=-2.667+2.186X1-2.167X2+0.725X3+0.976X4.

Accounting Fraud: an estimation of detection probability

Directory of Open Access Journals (Sweden)

Artur Filipe Ewald Wuerges

2014-12-01

Full Text Available Financial statement fraud (FSF is costly for investors and can damage the credibility of the audit profession. To prevent and detect fraud, it is helpful to know its causes. The binary choice models (e.g. logit and probit commonly used in the extant literature, however, fail to account for undetected cases of fraud and thus present unreliable hypotheses tests. Using a sample of 118 companies accused of fraud by the Securities and Exchange Commission (SEC, we estimated a logit model that corrects the problems arising from undetected frauds in U.S. companies. To avoid multicollinearity problems, we extracted seven factors from 28 variables using the principal factors method. Our results indicate that only 1.43 percent of the instances of FSF were publicized by the SEC. Of the six significant variables included in the traditional, uncorrected logit model, three were found to be actually non-significant in the corrected model. The likelihood of FSF is 5.12 times higher when the firm’s auditor issues an adverse or qualified report.

Bayesian non parametric modelling of Higgs pair production

Directory of Open Access Journals (Sweden)

Scarpa Bruno

2017-01-01

Full Text Available Statistical classification models are commonly used to separate a signal from a background. In this talk we face the problem of isolating the signal of Higgs pair production using the decay channel in which each boson decays into a pair of b-quarks. Typically in this context non parametric methods are used, such as Random Forests or different types of boosting tools. We remain in the same non-parametric framework, but we propose to face the problem following a Bayesian approach. A Dirichlet process is used as prior for the random effects in a logit model which is fitted by leveraging the Polya-Gamma data augmentation. Refinements of the model include the insertion in the simple model of P-splines to relate explanatory variables with the response and the use of Bayesian trees (BART to describe the atoms in the Dirichlet process.

Identifying response styles: A latent-class bilinear multinomial logit model

NARCIS (Netherlands)

van Rosmalen, J.; van Herk, H.; Groenen, P.J.F.

2010-01-01

Respondents can vary strongly in the way they use rating scales. Specifically, respondents can exhibit a variety of response styles, which threatens the validity of the responses. The purpose of this article Is to investigate how response style and content of the items affect rating scale responses.

Nonclassical measurements errors in nonlinear models

DEFF Research Database (Denmark)

Madsen, Edith; Mulalic, Ismir

Discrete choice models and in particular logit type models play an important role in understanding and quantifying individual or household behavior in relation to transport demand. An example is the choice of travel mode for a given trip under the budget and time restrictions that the individuals...... estimates of the income effect it is of interest to investigate the magnitude of the estimation bias and if possible use estimation techniques that take the measurement error problem into account. We use data from the Danish National Travel Survey (NTS) and merge it with administrative register data...... that contains very detailed information about incomes. This gives a unique opportunity to learn about the magnitude and nature of the measurement error in income reported by the respondents in the Danish NTS compared to income from the administrative register (correct measure). We find that the classical...

A dynamic analysis of interfuel substitution for Swedish heating plants

International Nuclear Information System (INIS)

Braennlund, Runar; Lundgren, Tommy

2004-01-01

This paper estimates a dynamic model of interfuel substitution for Swedish heating plants. We use the cost share linear logit model developed by Considine and Mount [Considine, T.J., Mount, T.D., 1984. The use of linear logit models for dynamic input demand systems. Review of Economics and Statistics 66, 434-443]. All estimated own-price elasticities are negative and all cross-price elasticities are positive. The estimated dynamic adjustment rate parameter is small, however, increasing with the size of the plant and time, indicating fast adjustments in the fuel mix when changing relative fuel prices. The estimated model is used to illustrate the effects of two different policy changes

Discrete Choice Model of Food Store Trips Using National Household Food Acquisition and Purchase Survey (FoodAPS)

OpenAIRE

Hillier, Amy; Smith, Tony E.; Whiteman, Eliza D.; Chrisinger, Benjamin W.

2017-01-01

Where households across income levels shop for food is of central concern within a growing body of research focused on where people live relative to where they shop, what they purchase and eat, and how those choices influence the risk of obesity and chronic disease. We analyzed data from the National Household Food Acquisition and Purchase Survey (FoodAPS) using a conditional logit model to determine where participants shop for food to be prepared and eaten at home and how individual and hous...

A multiclass vehicular dynamic traffic flow model for main roads and dedicated lanes/roads of multimodal transport network

Energy Technology Data Exchange (ETDEWEB)

Sossoe, K.S., E-mail: kwami.sossoe@irt-systemx.fr [TECHNOLOGICAL RESEARCH INSTITUTE SYSTEMX (France); Lebacque, J-P., E-mail: jean-patrick.lebacque@ifsttar.fr [UPE/IFSTTAR-COSYS-GRETTIA (France)

2015-03-10

We present in this paper a model of vehicular traffic flow for a multimodal transportation road network. We introduce the notion of class of vehicles to refer to vehicles of different transport modes. Our model describes the traffic on highways (which may contain several lanes) and network transit for pubic transportation. The model is drafted with Eulerian and Lagrangian coordinates and uses a Logit model to describe the traffic assignment of our multiclass vehicular flow description on shared roads. The paper also discusses traffic streams on dedicated lanes for specific class of vehicles with event-based traffic laws. An Euler-Lagrangian-remap scheme is introduced to numerically approximate the model’s flow equations.

Incidence of late rectal bleeding in high-dose conformal radiotherapy of prostate cancer using equivalent uniform dose-based and dose-volume-based normal tissue complication probability models

International Nuclear Information System (INIS)

Soehn, Matthias; Yan Di; Liang Jian; Meldolesi, Elisa; Vargas, Carlos; Alber, Markus

2007-01-01

Purpose: Accurate modeling of rectal complications based on dose-volume histogram (DVH) data are necessary to allow safe dose escalation in radiotherapy of prostate cancer. We applied different equivalent uniform dose (EUD)-based and dose-volume-based normal tissue complication probability (NTCP) models to rectal wall DVHs and follow-up data for 319 prostate cancer patients to identify the dosimetric factors most predictive for Grade ≥ 2 rectal bleeding. Methods and Materials: Data for 319 patients treated at the William Beaumont Hospital with three-dimensional conformal radiotherapy (3D-CRT) under an adaptive radiotherapy protocol were used for this study. The following models were considered: (1) Lyman model and (2) logit-formula with DVH reduced to generalized EUD (3) serial reconstruction unit (RU) model (4) Poisson-EUD model, and (5) mean dose- and (6) cutoff dose-logistic regression model. The parameters and their confidence intervals were determined using maximum likelihood estimation. Results: Of the patients, 51 (16.0%) showed Grade 2 or higher bleeding. As assessed qualitatively and quantitatively, the Lyman- and Logit-EUD, serial RU, and Poisson-EUD model fitted the data very well. Rectal wall mean dose did not correlate to Grade 2 or higher bleeding. For the cutoff dose model, the volume receiving > 73.7 Gy showed most significant correlation to bleeding. However, this model fitted the data more poorly than the EUD-based models. Conclusions: Our study clearly confirms a volume effect for late rectal bleeding. This can be described very well by the EUD-like models, of which the serial RU- and Poisson-EUD model can describe the data with only two parameters. Dose-volume-based cutoff-dose models performed worse

The importance of regret minimization in the choice for renewable energy programmes: Evidence from a discrete choice experiment

International Nuclear Information System (INIS)

Boeri, Marco; Longo, Alberto

2017-01-01

This study provides a methodologically rigorous attempt to disentangle the impact of various factors – unobserved heterogeneity, information and environmental attitudes – on the inclination of individuals to exhibit either a utility maximization or a regret minimization behaviour in a discrete choice experiment for renewable energy programmes described by four attributes: greenhouse gas emissions, power outages, employment in the energy sector, and electricity bill. We explore the ability of different models – multinomial logit, random parameters logit, and hybrid latent class – and of different choice paradigms – utility maximization and regret minimization – in explaining people's choices for renewable energy programmes. The “pure” random regret random parameters logit model explains the choices of our respondents better than other models, indicating that regret is an important choice paradigm, and that choices for renewable energy programmes are mostly driven by regret, rather than by rejoice. In particular, we find that our respondents' choices are driven more by changes in greenhouse gas emissions than by reductions in power outages. Finally, we find that changing the level of information to one attribute has no effect on choices, and that being a member of an environmental organization makes a respondent more likely to be associated with the utility maximization choice framework. - Highlights: • The first paper to use the Random Regret Minimization choice paradigm in energy economics • With a hybrid latent class model, choices conform to either utility or pure random regret. • The pure random regret random parameters logit model outperforms other models. • Reducing greenhouse gas emissions is more important than reducing power outages.

Don’t Work, Work at Home, or Commute? Discrete Choice Models of the Decision for San Francisco Bay Area Residents

OpenAIRE

Ory, D T; Mokhtarian, Patricia L

2005-01-01

Using socio-demographic, personality, and attitudinal data from 1,680 residents of the San Francisco Bay Area, we develop and estimate binary, multinomial, and nested logit models of the choice to work or not, whether or not to work at home, and whether to commute all of the time or some of the time (either by only working part time, or by working a compressed work week, or by telecommuting some of the time). To our knowledge, these are the first models of all these choices simultaneously. Th...

Heterogeneity in the WTP for recreational access

DEFF Research Database (Denmark)

Campbell, Danny; Vedel, Suzanne Elizabeth; Thorsen, Bo Jellesmark

2014-01-01

In this study we have addressed appropriate modelling of heterogeneity in willingness to pay (WTP) for environmental goods, and have demonstrated its importance using a case of forest access in Denmark. We compared WTP distributions for four models: (1) a multinomial logit model, (2) a mixed logit...... model assuming a univariate Normal distribution, (3) or assuming a multivariate Normal distribution allowing for correlation across attributes, and (4) a mixture of two truncated Normal distributions, allowing for correlation among attributes. In the first two models mean WTP for enhanced access...... was negative. However, models accounting for preference heterogeneity found a positive mean WTP, but a large sub-group with negative WTP. Accounting for preference heterogeneity can alter overall conclusions, which highlights the importance of this for policy recommendations....

Sample selection and taste correlation in discrete choice transport modelling

DEFF Research Database (Denmark)

Mabit, Stefan Lindhard

2008-01-01

explain counterintuitive results in value of travel time estimation. However, the results also point at the difficulty of finding suitable instruments for the selection mechanism. Taste heterogeneity is another important aspect of discrete choice modelling. Mixed logit models are designed to capture...... the question for a broader class of models. It is shown that the original result may be somewhat generalised. Another question investigated is whether mode choice operates as a self-selection mechanism in the estimation of the value of travel time. The results show that self-selection can at least partly...... of taste correlation in willingness-to-pay estimation are presented. The first contribution addresses how to incorporate taste correlation in the estimation of the value of travel time for public transport. Given a limited dataset the approach taken is to use theory on the value of travel time as guidance...

Application of rrm as behavior mode choice on modelling transportation

Science.gov (United States)

Surbakti, M. S.; Sadullah, A. F.

2018-03-01

Transportation mode selection, the first step in transportation planning process, is probably one of the most important planning elements. The development of models that can explain the preference of passengers regarding their chosen mode of public transport option will contribute to the improvement and development of existing public transport. Logit models have been widely used to determine the mode choice models in which the alternative are different transport modes. Random Regret Minimization (RRM) theory is a theory developed from the behavior to choose (choice behavior) in a state of uncertainty. During its development, the theory was used in various disciplines, such as marketing, micro economy, psychology, management, and transportation. This article aims to show the use of RRM in various modes of selection, from the results of various studies that have been conducted both in north sumatera and western Java.

Risk Pricing in Emerging Economies: Credit Scoring and Private Banking in Iran

Directory of Open Access Journals (Sweden)

Yiannis Anagnostopoulos

2016-01-01

Full Text Available Iran’s banking industry as a developing country is comparatively very new to risk management practices. An inevitable predictive implication of this rapid growth is the growing concerns with regard to credit risk management which is the motivation of conducting this research. The paper focuses on the credit scoring aspect of credit risk management using both logit and probit regression approaches. Real data on corporate customers are available for conducting this research which is also a contribution to this area for all other developing countries. Our questions focus on how future customers can be classified in terms of credibility, which models and methods are more effective in better capturing risks. Findings suggest that probit approaches are more effective in capturing the significance of variables and goodness-of-fitness tests. Seven variables of the Ohlson O-Score model are used: CL_CA, INTWO, OENEG, TA_TL, SIZE, WCAP_TA, and ROA; two were found to be statistically significant in logit (ROA, TL_TA and three were statistically significant in probit (ROA, TL_TA, SIZE. Also, CL_CA, ROA, and WCAP_TA were the three variables with an unexpected correlation to the probability of default. The prediction power with the cut-off point is set equal to 26% and 56.91% for defaulted customers in both logit and probit models. However, logit achieved 54.85% correct estimation of defaulted assets, 0.37% more than what probit estimated.

The interrelation between premenstrual syndrome and major depression: Results from a population-based sample

Directory of Open Access Journals (Sweden)

Weiss Carine

2011-10-01

Full Text Available Abstract Background Research about the relationship between premenstrual syndrome (PMS and major depression is limited. This study examined the relationship between moderate to severe PMS and major depression in a population-based sample of women of reproductive age. The objectives of the study were to assess the association between premenstrual syndrome and major depression, to analyse how PMS and major depression differ and to characterise the group of women who report both PMS and major depression. Methods Data were obtained from the Swiss Health Survey 2007. Included in the analysis was data from women under the age of 55 without hysterectomy and who answered the questions on PMS symptoms. The population-based sample consisted of 3518 women. Weighted prevalence rates were calculated and relative risk ratios for PMS, major depression and women who reported both PMS and major depression, were calculated with logistic multinominal logit regression. Results The prevalence of major depression was 11.3% in women screening positive for moderate PMS and 24.6% in women screening positive for severe PMS. Compared to women without any of these conditions, women who reported moderate to severe alcohol consumption had a lower risk for PMS. Women reporting use of antidepressants, and use of oral contraceptives had a higher risk for major depression compared to women without any of these conditions. Women reporting work dissatisfaction had a higher risk for PMS. A higher relative risk to report both PMS and major depression compared to women without PMS or major depression was related to factors such as high psychological distress, low mastery, psychotropic drug consumption, and low self-rated health. Conclusions The results suggested that women who suffer from both PMS and major depression are more impaired compared to women with only one disorder. The results further indicated that PMS and major depression are different disorders that can, however, co-occur.

MODELING THE DEMAND FOR E85 IN THE UNITED STATES

Energy Technology Data Exchange (ETDEWEB)

Liu, Changzheng [ORNL; Greene, David L [ORNL

2013-10-01

How demand for E85 might evolve in the future in response to changing economics and policies is an important subject to include in the National Energy Modeling System (NEMS). This report summarizes a study to develop an E85 choice model for NEMS. Using the most recent data from the states of Minnesota, North Dakota, and Iowa, this study estimates a logit model that represents E85 choice as a function of prices of E10 and E85, as well as fuel availability of E85 relative to gasoline. Using more recent data than previous studies allows a better estimation of non-fleet demand and indicates that the price elasticity of E85 choice appears to be higher than previously estimated. Based on the results of the econometric analysis, a model for projecting E85 demand at the regional level is specified. In testing, the model produced plausible predictions of US E85 demand to 2040.

Modeling the coupled return-spread high frequency dynamics of large tick assets

Science.gov (United States)

Curato, Gianbiagio; Lillo, Fabrizio

2015-01-01

Large tick assets, i.e. assets where one tick movement is a significant fraction of the price and bid-ask spread is almost always equal to one tick, display a dynamics in which price changes and spread are strongly coupled. We present an approach based on the hidden Markov model, also known in econometrics as the Markov switching model, for the dynamics of price changes, where the latent Markov process is described by the transitions between spreads. We then use a finite Markov mixture of logit regressions on past squared price changes to describe temporal dependencies in the dynamics of price changes. The model can thus be seen as a double chain Markov model. We show that the model describes the shape of the price change distribution at different time scales, volatility clustering, and the anomalous decrease of kurtosis. We calibrate our models based on Nasdaq stocks and we show that this model reproduces remarkably well the statistical properties of real data.

Working hours and depressive symptoms over 7 years: evidence from a Korean panel study.

Science.gov (United States)

Ahn, Seoyeon

2018-04-01

This study aims to examine how working hours influence depressive symptoms and the association between working hours and depressive symptoms differently across genders. The sample consists of salaried workers aged 25-64 years who participated in two consecutive waves of the seven-wave Korean Welfare Panel Study (2007-2013) (n = 6813 individuals, 27,986 observations) which is a survey of a nationally representative sample of the South Korean population. I apply logit regression and fixed-effects logit regression to examine the causal relation between (intra-)individual changes of working hours and depressive symptoms over a 7-year period. Results from logit model and fixed-effects logit model show that less than 30 h of work per week and more than 60 h of work per week are associated with significantly higher levels of depressive symptoms. Sex-stratified analyses reveal that women who worked over 60 h per week were at increased risk of showing depressive symptoms compared with women who worked 30-40 h per week. No significant increase in depressive symptoms was seen in men who worked more than 60 h per week. However, men working less than 30 h per week are more likely to report higher levels of depressive symptoms. These results suggest that work arrangement affects the mental health of men and women differently.

A Comparison between Discrimination Indices and Item-Response Theory Using the Rasch Model in a Clinical Course Written Examination of a Medical School.

Science.gov (United States)

Park, Jong Cook; Kim, Kwang Sig

2012-03-01

The reliability of test is determined by each items' characteristics. Item analysis is achieved by classical test theory and item response theory. The purpose of the study was to compare the discrimination indices with item response theory using the Rasch model. Thirty-one 4th-year medical school students participated in the clinical course written examination, which included 22 A-type items and 3 R-type items. Point biserial correlation coefficient (C(pbs)) was compared to method of extreme group (D), biserial correlation coefficient (C(bs)), item-total correlation coefficient (C(it)), and corrected item-total correlation coeffcient (C(cit)). Rasch model was applied to estimate item difficulty and examinee's ability and to calculate item fit statistics using joint maximum likelihood. Explanatory power (r2) of Cpbs is decreased in the following order: C(cit) (1.00), C(it) (0.99), C(bs) (0.94), and D (0.45). The ranges of difficulty logit and standard error and ability logit and standard error were -0.82 to 0.80 and 0.37 to 0.76, -3.69 to 3.19 and 0.45 to 1.03, respectively. Item 9 and 23 have outfit > or =1.3. Student 1, 5, 7, 18, 26, 30, and 32 have fit > or =1.3. C(pbs), C(cit), and C(it) are good discrimination parameters. Rasch model can estimate item difficulty parameter and examinee's ability parameter with standard error. The fit statistics can identify bad items and unpredictable examinee's responses.

Substitution between energy, capital and labour within industrial companies: A micro panel data analysis

International Nuclear Information System (INIS)

Arnberg, Soeren; Bjoerner, Thomas Bue

2007-01-01

Based on micro panel data for industrial companies, we estimate factor demand models with electricity, other energy, labour and machine capital as flexible inputs using both the translog and the linear logit specification. As opposed to the few previous micro (cross-section) data studies we find that both electricity and other energy are complements with capital. Substitution between electricity and other energy is limited. The own-price elasticity for electricity is -0.21 in the translog model and -0.19 in the linear logit model. The corresponding own-price elasticities are -0.45 and -0.23 for other energy, -0.08 and -0.05 for labour and -0.45 and -0.34 for capital. (author)

A Study of Commuters’ Decision-Making When Delaying Departure for Work-Home Trips

Science.gov (United States)

Que, Fangjie; Wang, Wei

2017-12-01

Studies on the travel behaviors and patterns of residents are important to the arrangement of urban layouts and urban traffic planning. However, research on the characteristics of the decision-making behavior regarding departure time is not fully expanded yet. In this paper, the research focuses on commuters’ decision-making behavior regarding departure delay. According to the 2013 travel survey data of Suzhou City, a nested logit (NL) model was built to represent the probabilities of individual choices. Parameter calibration was conducted, so that the significant factors influencing the departure delay were obtained. Ultimately, the results of the NL model indicated that it performed better and with higher precision, compared to the traditional multinomial logit (MNL) model.

Statistical aspects of radioimmunoassay

International Nuclear Information System (INIS)

Rodbard, D.; Guardabasso, V.; Munson, P.J.

1987-01-01

The logit-log method, and the closely related four-parameter logistic method, are usually sufficient and optimal for routine RIA data processing. The authors compared the advantages and limitations of these approaches. They also provided a strategy to deal with the relatively rare cases where the logit-log and logistic methods. This requires consideration of the mass action law models, spline methods, some extensions of the logistic, and a new method, combining the virtues of the spline and the logistic families of methods

Spatial Model of Deforestation in Jambi Province for The Periode 1990–2011

Directory of Open Access Journals (Sweden)

Putu Ananta Wijaya

2015-12-01

Full Text Available In the last 2 decades, deforestation had been an international issue due to its effect to climate change. This study describes a spatial modelling for predicting deforestation in Jambi Province. The main study objective was to find out the best spatial model for predicting deforestation by considering the spatial contexts. The main data used for the analysis were multitemporal Landsat TM images acquired in 1990, 2000, and 2011, the existing land cover maps published by the Ministry of Forestry, statistical data and ground truth. Prior to any other analyses, all districts within the study area were classified into 2 typologies, i.e. low-rate and high-rate deforestation districs on the basis of social and economic factors by using clustering approaches. The spatial models of deforestation were developed by using least-square methods. The study found that the spatial model of deforestation for low-rate deforestation area is Logit (Deforestation = -2.7046 – 0.000397*JH90 + 0.000002*JJ – 0.000111*JKBN90 (distance from forest edge (distance from road + 0.000096 *JP90 + 0.044227*PDK90 + 0.148187 *E – (distance from estate crop edge (distance from agricultural crop edge (population density (elevation 0.131178*S(slope; while for the high-speed deforestation area is Logit (Deforestation = 9.1727 – 0.000788*JH90(distance – 0.000065 *JJ – 0.000091*JKBN90 + 0.000005 *JP90 – from forest edge (distance from road (distance from estate crop edge (distance from agricultural crop edge 0.070372*PDK90 + 11.268539*E – 1.495198*S . The low-rate and high-rate deforestation (population density (elevation (slope models had relatively good ROC (Relative Operating Characteristics values of 91.32% and 99.08%, respectively. The study concludes that the deforestation rate was significantly affected by accessibility (distance from forest edge, distance from estate crop edge, edge from agricultural land, biophysical condition (elevation and slope as well as

A comparison of generalized multinomial logit, random parameters logit, wtp-space and latent class models to studying consumers' preferences for animal welfare

OpenAIRE

Kallas, Zein; Borrisser-Pairó,, Francesc; Martínez, Beatriz; Vieira, Ceferina; Panella-Riera, Nuria; Olivar, Maria Angels; Gil Roig, José María

2016-01-01

The European societies are requiring that animals to be raised as closely as possible to their natural conditions. The growing concerns about animal welfare is resulting in continuous modifications of regulations and policies that led to ban of a number of intensive farming methods. The European authorities consider the pig welfare as a priority issue. They are studying to ban surgical pig castration by 2018, which may seriously affect markets and consumers due to boar tainted-meat. This stud...

Modelling Preference Heterogeneity for Theatre Tickets

DEFF Research Database (Denmark)

Baldin, Andrea; Bille, Trine

This paper analyzes the behavioural choice for theatre tickets using a rich dataset for 2010-2013 from the sale system of the Royal Danish National Theatre. A consumer who decides to attend a theater production faces multiple sources of price variation that depends on: socio-economic characterist......This paper analyzes the behavioural choice for theatre tickets using a rich dataset for 2010-2013 from the sale system of the Royal Danish National Theatre. A consumer who decides to attend a theater production faces multiple sources of price variation that depends on: socio......-economic characteristics, quality of the seat, day of the performance and timing of purchase. Except for the first case, factors of price differentiation involves a choice by the consumer among different ticket alternatives. Two modelling approaches, namely multinomial logit (with socio-demographic characteristics......) and latent class are proposed in order to model ticket purchase behaviour. These models allow us explicitly to take into account consumers' preference heterogeneity with respect to the attributes associated to each ticket alternative In addition, the distribution of the willingness-to-pay (WTP) of choice...

Intrafirm planning and mathematical modeling of owner's equity in industrial enterprises

Science.gov (United States)

Ponomareva, S. V.; Zheleznova, I. V.

2018-05-01

The article aims to review the different approaches to intrafirm planning of owner's equity in industrial enterprises. Since charter capital, additional capital and reserve capital do not change in the process of enterprise activity, the main interest lies on the field of share repurchases from shareholders and retained earnings within the owner's equity of the enterprise. In order to study the effect of share repurchases on the activities of the enterprise, let us use such mathematical methods as event study and econometric modeling. This article describes the step-by-step algorithm of carrying out event study and justifies the choice of Logit model in econometric analysis. The article represents basic results of conducted regression analysis on the effect of share repurchases on the key financial indicators in industrial enterprises.

Rigorously testing multialternative decision field theory against random utility models.

Science.gov (United States)

Berkowitsch, Nicolas A J; Scheibehenne, Benjamin; Rieskamp, Jörg

2014-06-01

Cognitive models of decision making aim to explain the process underlying observed choices. Here, we test a sequential sampling model of decision making, multialternative decision field theory (MDFT; Roe, Busemeyer, & Townsend, 2001), on empirical grounds and compare it against 2 established random utility models of choice: the probit and the logit model. Using a within-subject experimental design, participants in 2 studies repeatedly choose among sets of options (consumer products) described on several attributes. The results of Study 1 showed that all models predicted participants' choices equally well. In Study 2, in which the choice sets were explicitly designed to distinguish the models, MDFT had an advantage in predicting the observed choices. Study 2 further revealed the occurrence of multiple context effects within single participants, indicating an interdependent evaluation of choice options and correlations between different context effects. In sum, the results indicate that sequential sampling models can provide relevant insights into the cognitive process underlying preferential choices and thus can lead to better choice predictions. PsycINFO Database Record (c) 2014 APA, all rights reserved.

A Mixed Logit Model of Homeowner Preferences for Wildfire Hazard Reduction

Science.gov (United States)

Thomas P. Holmes; John Loomis; Armando Gonzalez-Caban

2010-01-01

People living in the wildland-urban interface (WUI) are at greater risk of suffering major losses of property and life from wildfires. Over the past several decades the prevailing view has been that wildfire risk in rural areas was exogenous to the activities of homeowners. In response to catastrophic fires in the WUI over the past few years, recent approaches to fire...

Mixed multinomial logit model for out-of-home leisure activity choice

NARCIS (Netherlands)

Grigolon, A.B.; Kemperman, A.D.A.M.; Timmermans, H.J.P.

2013-01-01

This paper documents the design and results of a study on the factors influencing the choice of out-of-home leisure activities. Influencing factors seem related to socio-demographic characteristics, personal preferences, characteristics of the built environment and other aspects of the activities

Identifying Unknown Response Styles: A Latent-Class Bilinear Multinomial Logit Model

NARCIS (Netherlands)

J.M. van Rosmalen (Joost); H. van Herk (Hester); P.J.F. Groenen (Patrick)

2007-01-01

textabstractRespondents can vary significantly in the way they use rating scales. Specifically, respondents can exhibit varying degrees of response style, which threatens the validity of the responses. The purpose of this article is to investigate to what extent rating scale responses show response

On the potential of models for location and scale for genome-wide DNA methylation data.

Science.gov (United States)

Wahl, Simone; Fenske, Nora; Zeilinger, Sonja; Suhre, Karsten; Gieger, Christian; Waldenberger, Melanie; Grallert, Harald; Schmid, Matthias

2014-07-03

With the help of epigenome-wide association studies (EWAS), increasing knowledge on the role of epigenetic mechanisms such as DNA methylation in disease processes is obtained. In addition, EWAS aid the understanding of behavioral and environmental effects on DNA methylation. In terms of statistical analysis, specific challenges arise from the characteristics of methylation data. First, methylation β-values represent proportions with skewed and heteroscedastic distributions. Thus, traditional modeling strategies assuming a normally distributed response might not be appropriate. Second, recent evidence suggests that not only mean differences but also variability in site-specific DNA methylation associates with diseases, including cancer. The purpose of this study was to compare different modeling strategies for methylation data in terms of model performance and performance of downstream hypothesis tests. Specifically, we used the generalized additive models for location, scale and shape (GAMLSS) framework to compare beta regression with Gaussian regression on raw, binary logit and arcsine square root transformed methylation data, with and without modeling a covariate effect on the scale parameter. Using simulated and real data from a large population-based study and an independent sample of cancer patients and healthy controls, we show that beta regression does not outperform competing strategies in terms of model performance. In addition, Gaussian models for location and scale showed an improved performance as compared to models for location only. The best performance was observed for the Gaussian model on binary logit transformed β-values, referred to as M-values. Our results further suggest that models for location and scale are specifically sensitive towards violations of the distribution assumption and towards outliers in the methylation data. Therefore, a resampling procedure is proposed as a mode of inference and shown to diminish type I error rate in

The effects of improved maize technology on household welfare in Buruku, Benue State, Nigeria

Directory of Open Access Journals (Sweden)

Victoria I. Audu

2014-12-01

Full Text Available This study was carried out to determine the welfare effects of improved maize technology in Buruku Local Government Area of Benue State, Nigeria. The study also examined the determinants of the adoption of improved maize technology. Structured questionnaires were used in collecting the primary data for the study. A multi-stage random technique was used in selecting 125 farm households for the study. The Logit and ordinary least square (OLS models were used in analyzing the data. The OLS results show that adoption of improved maize varieties is positively and significantly related to household welfare and thus has contributed to moving farm households out of poverty. Other variables found to be statistically significant in explaining household welfare are education, household size, and landholding. The Logit results show that age, household size, off-farm income, and education were found to be significant in influencing farmers’ adoption decisions. Some robustness checks were performed with different specifications of the Logit and OLS models as well as re-estimation with propensity matching score approach. Overall, the results are robust to different specifications.

Performance of various mathematical methods for calculation of radioimmunoassay results

International Nuclear Information System (INIS)

Sandel, P.; Vogt, W.

1977-01-01

Interpolation and regression methods are available for computer aided determination of radioimmunological end results. We compared the performance of eight algorithms (weighted and unweighted linear logit-log regression, quadratic logit-log regression, Rodbards logistic model in the weighted and unweighted form, smoothing spline interpolation with a large and small smoothing factor and polygonal interpolation) on the basis of three radioimmunoassays with different reference curve characteristics (digoxin, estriol, human chorionic somatomammotropin = HCS). Great store was set by the accuracy of the approximation at the intermediate points on the curve, ie. those points that lie midway between two standard concentrations. These concentrations were obtained by weighing and inserted as unknown samples. In the case of digoxin and estriol the polygonal interpolation provided the best results while the weighted logit-log regression proved superior in the case of HCS. (orig.) [de

A Monte Carlo experiment to analyze the curse of dimensionality in estimating random coefficients models with a full variance–covariance matrix

DEFF Research Database (Denmark)

Cherchi, Elisabetta; Guevara, Cristian Angelo

2012-01-01

of parameters increases is usually known as the “curse of dimensionality” in the simulation methods. We investigate this problem in the case of the random coefficients Logit model. We compare the traditional Maximum Simulated Likelihood (MSL) method with two alternative estimation methods: the Expectation......–Maximization (EM) and the Laplace Approximation (HH) methods that do not require simulation. We use Monte Carlo experimentation to investigate systematically the performance of the methods under different circumstances, including different numbers of variables, sample sizes and structures of the variance...

Modeling detour behavior of pedestrian dynamics under different conditions

Science.gov (United States)

Qu, Yunchao; Xiao, Yao; Wu, Jianjun; Tang, Tao; Gao, Ziyou

2018-02-01

Pedestrian simulation approach has been widely used to reveal the human behavior and evaluate the performance of crowd evacuation. In the existing pedestrian simulation models, the social force model is capable of predicting many collective phenomena. Detour behavior occurs in many cases, and the important behavior is a dominate factor of the crowd evacuation efficiency. However, limited attention has been attracted for analyzing and modeling the characteristics of detour behavior. In this paper, a modified social force model integrated by Voronoi diagram is proposed to calculate the detour direction and preferred velocity. Besides, with the consideration of locations and velocities of neighbor pedestrians, a Logit-based choice model is built to describe the detour direction choice. The proposed model is applied to analyze pedestrian dynamics in a corridor scenario with either unidirectional or bidirectional flow, and a building scenario in real-world. Simulation results show that the modified social force model including detour behavior could reduce the frequency of collision and deadlock, increase the average speed of the crowd, and predict more practical crowd dynamics with detour behavior. This model can also be potentially applied to understand the pedestrian dynamics and design emergent management strategies for crowd evacuations.

DETERMININGS OF FARM WORK ALLOCATION IN BRAZILIAN REGIONS

Directory of Open Access Journals (Sweden)

Filipe de Morais Cangussu Pessoa

2013-03-01

Full Text Available The aim of this paper was to analyze the determinings of farm work allocation in Brazilian regions, based on micro data of National Household Sample Survey 2009. For that, the empirical procedure consisted in the use of two models: Confirmatory Factor Analysis and the Logit Model. The model Confirmatory Factor Analysis showed good fit and defined two latent variables: qualification and income. As to the Logit Model, the results showed that the fact of a man living in rural areas increases the likelihood of being allocated in farm work, however if he is white this probability decrease. Besides, the variables qualification and income have a negative relation with farm work allocation, being the Midwest region that contributed most for people being allocated in farm work.

Bayesian informative dropout model for longitudinal binary data with random effects using conditional and joint modeling approaches.

Science.gov (United States)

Chan, Jennifer S K

2016-05-01

Dropouts are common in longitudinal study. If the dropout probability depends on the missing observations at or after dropout, this type of dropout is called informative (or nonignorable) dropout (ID). Failure to accommodate such dropout mechanism into the model will bias the parameter estimates. We propose a conditional autoregressive model for longitudinal binary data with an ID model such that the probabilities of positive outcomes as well as the drop-out indicator in each occasion are logit linear in some covariates and outcomes. This model adopting a marginal model for outcomes and a conditional model for dropouts is called a selection model. To allow for the heterogeneity and clustering effects, the outcome model is extended to incorporate mixture and random effects. Lastly, the model is further extended to a novel model that models the outcome and dropout jointly such that their dependency is formulated through an odds ratio function. Parameters are estimated by a Bayesian approach implemented using the user-friendly Bayesian software WinBUGS. A methadone clinic dataset is analyzed to illustrate the proposed models. Result shows that the treatment time effect is still significant but weaker after allowing for an ID process in the data. Finally the effect of drop-out on parameter estimates is evaluated through simulation studies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modelling Gender Differences in the Economic and Social Influences of Obesity in Australian Young People.

Science.gov (United States)

Avsar, Gulay; Ham, Roger; Tannous, W Kathy

2017-03-03

In Australia, as in many other developed economies, the prevalence of obesity has risen significantly in all age groups and especially in young males and females over the past decade. Using data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey, this paper investigates the influence of economic, personality and social factor demographics on the incidence of obesity in Australian youths. The study uses two random parameters logit models, including one that allows for gender-specific differences in the conditioning variables. The models reveal notable differences between the most important variables affecting the incidence of obesity amongst females compared to males. These differences are notable to consider for policy and intervention programs aimed at reducing the problem of obesity.

Modelling Gender Differences in the Economic and Social Influences of Obesity in Australian Young People

Directory of Open Access Journals (Sweden)

Gulay Avsar

2017-03-01

Full Text Available In Australia, as in many other developed economies, the prevalence of obesity has risen significantly in all age groups and especially in young males and females over the past decade. Using data from the Household, Income and Labour Dynamics in Australia (HILDA Survey, this paper investigates the influence of economic, personality and social factor demographics on the incidence of obesity in Australian youths. The study uses two random parameters logit models, including one that allows for gender-specific differences in the conditioning variables. The models reveal notable differences between the most important variables affecting the incidence of obesity amongst females compared to males. These differences are notable to consider for policy and intervention programs aimed at reducing the problem of obesity.

Item selection via Bayesian IRT models.

Science.gov (United States)

Arima, Serena

2015-02-10

With reference to a questionnaire that aimed to assess the quality of life for dysarthric speakers, we investigate the usefulness of a model-based procedure for reducing the number of items. We propose a mixed cumulative logit model, which is known in the psychometrics literature as the graded response model: responses to different items are modelled as a function of individual latent traits and as a function of item characteristics, such as their difficulty and their discrimination power. We jointly model the discrimination and the difficulty parameters by using a k-component mixture of normal distributions. Mixture components correspond to disjoint groups of items. Items that belong to the same groups can be considered equivalent in terms of both difficulty and discrimination power. According to decision criteria, we select a subset of items such that the reduced questionnaire is able to provide the same information that the complete questionnaire provides. The model is estimated by using a Bayesian approach, and the choice of the number of mixture components is justified according to information criteria. We illustrate the proposed approach on the basis of data that are collected for 104 dysarthric patients by local health authorities in Lecce and in Milan. Copyright © 2014 John Wiley & Sons, Ltd.

The choice of forest site for recreation

DEFF Research Database (Denmark)

Agimass, Fitalew; Lundhede, Thomas; Panduro, Toke Emil

2018-01-01

logit as well as a random parameter logit model. The variables that are found to affect the choice of forest site to a visit for recreation include: forest area, tree species composition, forest density, availability of historical sites, terrain difference, state ownership, and distance. Regarding......In this paper, we investigate the factors that can influence the site choice of forest recreation. Relevant attributes are identified by using spatial data analysis from a questionnaire asking people to indicate their most recent forest visits by pinpointing on a map. The main objectives...

The relationship between venture capital investment and macro economic variables via statistical computation method

Science.gov (United States)

Aygunes, Gunes

2017-07-01

The objective of this paper is to survey and determine the macroeconomic factors affecting the level of venture capital (VC) investments in a country. The literary depends on venture capitalists' quality and countries' venture capital investments. The aim of this paper is to give relationship between venture capital investment and macro economic variables via statistical computation method. We investigate the countries and macro economic variables. By using statistical computation method, we derive correlation between venture capital investments and macro economic variables. According to method of logistic regression model (logit regression or logit model), macro economic variables are correlated with each other in three group. Venture capitalists regard correlations as a indicator. Finally, we give correlation matrix of our results.

MEASURING CAR DRIVERS’ WILLINGNESS TO PAY FOR IMPROVED INTERCITY TRANSPORTATION SERVICE: A CASE STUDY IN LIBYA

Directory of Open Access Journals (Sweden)

MANSSOUR A. ABDULASALM MISKEEN

2016-08-01

Full Text Available The current study investigates solutions to optimize the intercity highway network and to facilitate the understanding of the transport mode of Libyans, according to the proposed transport policies, in terms of reducing car usage for intercity trips. In this study, different models namely the logit and spike models are applied to estimate the mean of the willingness to pay (WTP value for some proposed policies in order to be able to compare the results from each policy and analyses to what extent that each was regarded as suitable for our data characteristics. A large number of respondents were unwilling to pay any money for the different proposed policies on transportation. Therefore, the Spike model was used to avoid errors in estimation and create a WTP pricing model for the different proposed policies on transportation. The overall results indicate that the spike model outperforms the logit model significantly.

Labour market transitions and job satisfaction

NARCIS (Netherlands)

G.E. Bijwaard (Govert); A. van Dijk (Bram); J. de Koning (Jaap)

2003-01-01

textabstractThe paper investigates the relationship between job satisfaction and labour market transitions. Using a multinomial logit model, a model is estimated on the basis of individual data in which transitions are explained from individual characteristics, job characteristics, dissatisfaction

Combining ungrouped and grouped wildfire data to estimate fire risk

KAUST Repository

Hernandez-Magallanes, I.

2013-01-01

particular year. The probability model is based on the wildfire point process. Assuming a smooth intensity function, a locally weighted likelihood fit is used, which incorporates the group effect. A logit model is used under the assumption of the existence

A dynamic analysis of motorcycle ownership and usage: a panel data modeling approach.

Science.gov (United States)

Wen, Chieh-Hua; Chiou, Yu-Chiun; Huang, Wan-Ling

2012-11-01

This study aims to develop motorcycle ownership and usage models with consideration of the state dependence and heterogeneity effects based on a large-scale questionnaire panel survey on vehicle owners. To account for the independence among alternatives and heterogeneity among individuals, the modeling structure of motorcycle ownership adopts disaggregate choice models considering the multinomial, nested, and mixed logit formulations. Three types of panel data regression models--ordinary, fixed, and random effects--are developed and compared for motorcycle usage. The estimation results show that motorcycle ownership in the previous year does exercise a significantly positive effect on the number of motorcycles owned by households in the current year, suggesting that the state dependence effect does exist in motorcycle ownership decisions. In addition, the fixed effects model is the preferred specification for modeling motorcycle usage, indicating strong evidence for existence of heterogeneity. Among various management strategies evaluated under different scenarios, increasing gas prices and parking fees will lead to larger reductions in total kilometers traveled. Copyright © 2011 Elsevier Ltd. All rights reserved.

Exclusive queueing model including the choice of service windows

Science.gov (United States)

Tanaka, Masahiro; Yanagisawa, Daichi; Nishinari, Katsuhiro

2018-01-01

In a queueing system involving multiple service windows, choice behavior is a significant concern. This paper incorporates the choice of service windows into a queueing model with a floor represented by discrete cells. We contrived a logit-based choice algorithm for agents considering the numbers of agents and the distances to all service windows. Simulations were conducted with various parameters of agent choice preference for these two elements and for different floor configurations, including the floor length and the number of service windows. We investigated the model from the viewpoint of transit times and entrance block rates. The influences of the parameters on these factors were surveyed in detail and we determined that there are optimum floor lengths that minimize the transit times. In addition, we observed that the transit times were determined almost entirely by the entrance block rates. The results of the presented model are relevant to understanding queueing systems including the choice of service windows and can be employed to optimize facility design and floor management.

Patterns and correlates of solid waste disposal practices in Dar es ...

African Journals Online (AJOL)

USER

collection. Key words: Solid waste, garbage, waste disposal, waste management, Multinomial Logit model. INTRODUCTION. Urbanization introduces society to a new, modern way of ..... Multinomial logistic estimation. .... The trend of using.

Longitudinal analysis of categorical epidemiological data: a study of Three Mile Island.

Science.gov (United States)

Fienberg, S E; Bromet, E J; Follmann, D; Lambert, D; May, S M

1985-11-01

The accident at the Three Mile Island nuclear power plant in 1979 led to an unprecedented set of events with potentially life threatening implications. This paper focusses on the analysis of a longitudinal study of the psychological well-being of the mothers of young children living within 10 miles of the plant. The initial analyses of the data utilize loglinear/logit model techniques from the contingency table literature, and involve the fitting of a sequence of logit models. The inadequancies of these analyses are noted, and a new class of mixture models for logistic response structures is introduced to overcome the noted shortcomings. The paper includes a brief outline of the methodology relevant for the fitting of these models using the method of maximum likelihood, and then the model is applied to the TMI data. The paper concludes with a discussion of some of the substantive implications of the mixture model analysis.

Testing Benefits Transfer of Forest Recreation Values over a 20-year time Horizon

DEFF Research Database (Denmark)

Zandersen, Marianne; Termansen, Mette; Jensen, F.S.

2007-01-01

We conduct a functional benefit transfer over 20 years of total willingness to pay based on car-borne forest recreation in 52 forests, using a mixed logit specification of a random utility model and geographic information systems to allow heterogeneous preferences across the population and for he......We conduct a functional benefit transfer over 20 years of total willingness to pay based on car-borne forest recreation in 52 forests, using a mixed logit specification of a random utility model and geographic information systems to allow heterogeneous preferences across the population...... and for heterogeneity over space. Results show that preferences for some forest attributes, such as species diversity and age, as well as transport mode have changed significantly over the period. Updating the transfer model with present total demand for recreation improves the error margins by an average of 282......%. Average errors of the best transfer model remain 25%....

Collaboration and partnership in forest conservation: The role of ...

African Journals Online (AJOL)

Collaboration and partnership in forest conservation: The role of ... The results of a logit estimation model indicates that six factors (gender, ... Surprisingly, perceptions of economic and environmental benefits emerged as negatively significant.

Networks and Selection in International Migration to Spain

DEFF Research Database (Denmark)

Neubecker, Nina; Smolka, Marcel; Steinbacher, Anne

This paper provides new evidence on migrant networks as determinants of the scale and skill structure of migration, using aggregate data from a recent migration boom to Spain. We develop a three-level nested multinomial logit migration model. Our model accommodates varying degrees of similarity...

630 understanding farmers' response to climate variability in nigeria

African Journals Online (AJOL)

Osondu

Data were analyzed using descriptive statistics, and multinomial logit models. Farmers used multiple adaptation strategies; Crop Diversification (CD), Soil ... Increases in temperature, cloud ... and the effect of climate elements and their extreme ...

Analysis of the USMC FITREP: Contemporary or Inflexible?

National Research Council Canada - National Science Library

Jobst, Mark; Palmer, Jeffrey

2005-01-01

.... Using data from the USMC Officer Accession Career file (MCCOAC), a logit model is used to estimate the effects of TBS preference and other officer characteristics on retention to the seven year mark...

Explaining food insecurity among indigenous households of the Sierra Tarahumara in the Mexican state of Chihuahua

International Nuclear Information System (INIS)

Cordero-Ahiman, O.V.; Santellano-Estrada, E.; Garrido, A.

2017-01-01

Numerous studies have analyzed the factors that determine food security and explored the problem from regional or national points of view. However, there has been less research targeting an understanding of the food security problem at the household level in specific rural locations like indigenous communities. Indigenous groups are recognized as priority groups in Mexico, because they live in a situation of poverty. For this reason, the objective of this research was to investigate the determinants of food insecurity among the indigenous communities of the Sierra Tarahumara in Mexico. We used the Latin American and Caribbean Household Food Security Measurement Scale (ELCSA). This scale is useful for measuring food insecurity levels in households. A questionnaire was administered to 123 households. We employed the method based on Cronbach's alpha to measure internal consistency, which was 0.96. In addition, we estimated the main determinants of household food insecurity using both ordered logit model and binomial logit model. We found that approximately 59.35% of households were living in a situation of severe food insecurity. The two predictive models applied suggest that: i) income is the most important determinant of access to food; ii) increased maize production improves food security; iii) farmers consume their seed stocks in times of food scarcity, and iv) households are food insecure when the householders are in casual employment. Akaike's information criterion and the Bayesian information criterion suggest that the goodness of fit to the data was better for the ordered logit model.

Combining RP and SP data while accounting for large choice sets and travel mode

DEFF Research Database (Denmark)

Abildtrup, Jens; Olsen, Søren Bøye; Stenger, Anne

2015-01-01

set used for site selection modelling when the actual choice set considered is potentially large and unknown to the analyst. Easy access to forests also implies that around half of the visitors walk or bike to the forest. We apply an error-component mixed-logit model to simultaneously model the travel...

Joint Residence-Workplace Location Choice Model Based on Household Decision Behavior

Directory of Open Access Journals (Sweden)

Pengpeng Jiao

2015-01-01

Full Text Available Residence location and workplace are the two most important urban land-use types, and there exist strong interdependences between them. Existing researches often assume that one choice dimension is correlated to the other. Using the mixed logit framework, three groups of choice models are developed to illustrate such choice dependencies. First, for all households, this paper presents a basic methodology of the residence location and workplace choice without decision sequence based on the assumption that the two choice behaviors are independent of each other. Second, the paper clusters all households into two groups, choosing residence or workplace first, and formulates the residence location and workplace choice models under the constraint of decision sequence. Third, this paper combines the residence location and workplace together as the choice alternative and puts forward the joint choice model. A questionnaire survey is implemented in Beijing city to collect the data of 1994 households. Estimation results indicate that the joint choice model fits the data significantly better, and the elasticity effects analyses show that the joint choice model reflects the influences of relevant factors to the choice probability well and leads to the job-housing balance.

Original Research Original Research

African Journals Online (AJOL)

User

2013-06-23

Jun 23, 2013 ... conomics, College of Business and Economics, Wollega University, ost Box No: ... The Logit model is used to investigate .... providing subsidies, relief, and reducing taxes. The ... the minimum calorie requirement for survival.

An assessment of econometric models applied to fossil fuel power generation

International Nuclear Information System (INIS)

Gracceva, F.; Quercioli, R.

2001-01-01

The main purpose of this report is to provide a general view of those studies, in which the econometric approach is applied to the selection of fuel in fossil fired power generation, focusing the attention to the key role played by the fuel prices. The report consists of a methodological analysis and a survey of the studies available in literature. The methodological analysis allows to assess the adequateness of the econometric approach, in the electrical power utilities policy. With this purpose, the fundamentals of microeconomics, which are the basis of the econometric models, are pointed out and discussed, and then the hypotheses, which are needed to be assumed for complying the economic theory, are verified in their actual implementation in the power generation sector. The survey of the available studies provides a detailed description of the Translog and Logit models, and the results achieved with their application. From these results, the estimated models show to fit the data with good approximation, a certain degree of interfuel substitution and a meaningful reaction to prices on demand side [it

Propensity for Voluntary Travel Behavior Changes: An Experimental Analysis

DEFF Research Database (Denmark)

Meloni, Italo; Sanjust, Benedetta; Sottile, Eleonora

2013-01-01

In this paper we analyze individual propensity to voluntary travel behavior change combining concepts from theory of change with the methodologies deriving from behavioral models. In particular, following the theory of voluntary changes, we set up a two-week panel survey including soft measure...... implementation, which consisted of providing car users with a personalized travel plan after the first week of observation (before) and using the second week to monitoring the post-behavior (after). These data have then been used to estimate a Mixed Logit for the choice to use a personal vehicle or a light metro......; and a Multinomial Logit for the decision to change behavior. Results from both models show the relevance of providing information about available alternatives to individuals while promoting voluntary travel behavioral change....

Determinants of adoption and productivity of improved rice varieties ...

African Journals Online (AJOL)

The study employed adoption index, logit model and stochastic frontier model to assess the adoption status, its determinants and impact on farmers' productivity respectively. The results show that farmers have responded appreciably to intervention programme that promote the use of improved rice varieties with an adoption ...

Easy and flexible mixture distributions

DEFF Research Database (Denmark)

Fosgerau, Mogens; Mabit, Stefan L.

2013-01-01

We propose a method to generate flexible mixture distributions that are useful for estimating models such as the mixed logit model using simulation. The method is easy to implement, yet it can approximate essentially any mixture distribution. We test it with good results in a simulation study...

An optimal hierarchical decision model for a regional logistics network with environmental impact consideration.

Science.gov (United States)

Zhang, Dezhi; Li, Shuangyan; Qin, Jin

2014-01-01

This paper proposes a new model of simultaneous optimization of three-level logistics decisions, for logistics authorities, logistics operators, and logistics users, for regional logistics network with environmental impact consideration. The proposed model addresses the interaction among the three logistics players in a complete competitive logistics service market with CO2 emission charges. We also explicitly incorporate the impacts of the scale economics of the logistics park and the logistics users' demand elasticity into the model. The logistics authorities aim to maximize the total social welfare of the system, considering the demand of green logistics development by two different methods: optimal location of logistics nodes and charging a CO2 emission tax. Logistics operators are assumed to compete with logistics service fare and frequency, while logistics users minimize their own perceived logistics disutility given logistics operators' service fare and frequency. A heuristic algorithm based on the multinomial logit model is presented for the three-level decision model, and a numerical example is given to illustrate the above optimal model and its algorithm. The proposed model provides a useful tool for modeling competitive logistics services and evaluating logistics policies at the strategic level.

An Optimal Hierarchical Decision Model for a Regional Logistics Network with Environmental Impact Consideration

Directory of Open Access Journals (Sweden)

Dezhi Zhang

2014-01-01

Full Text Available This paper proposes a new model of simultaneous optimization of three-level logistics decisions, for logistics authorities, logistics operators, and logistics users, for regional logistics network with environmental impact consideration. The proposed model addresses the interaction among the three logistics players in a complete competitive logistics service market with CO2 emission charges. We also explicitly incorporate the impacts of the scale economics of the logistics park and the logistics users’ demand elasticity into the model. The logistics authorities aim to maximize the total social welfare of the system, considering the demand of green logistics development by two different methods: optimal location of logistics nodes and charging a CO2 emission tax. Logistics operators are assumed to compete with logistics service fare and frequency, while logistics users minimize their own perceived logistics disutility given logistics operators’ service fare and frequency. A heuristic algorithm based on the multinomial logit model is presented for the three-level decision model, and a numerical example is given to illustrate the above optimal model and its algorithm. The proposed model provides a useful tool for modeling competitive logistics services and evaluating logistics policies at the strategic level.

An Optimal Hierarchical Decision Model for a Regional Logistics Network with Environmental Impact Consideration

Science.gov (United States)

Zhang, Dezhi; Li, Shuangyan

2014-01-01

This paper proposes a new model of simultaneous optimization of three-level logistics decisions, for logistics authorities, logistics operators, and logistics users, for regional logistics network with environmental impact consideration. The proposed model addresses the interaction among the three logistics players in a complete competitive logistics service market with CO2 emission charges. We also explicitly incorporate the impacts of the scale economics of the logistics park and the logistics users' demand elasticity into the model. The logistics authorities aim to maximize the total social welfare of the system, considering the demand of green logistics development by two different methods: optimal location of logistics nodes and charging a CO2 emission tax. Logistics operators are assumed to compete with logistics service fare and frequency, while logistics users minimize their own perceived logistics disutility given logistics operators' service fare and frequency. A heuristic algorithm based on the multinomial logit model is presented for the three-level decision model, and a numerical example is given to illustrate the above optimal model and its algorithm. The proposed model provides a useful tool for modeling competitive logistics services and evaluating logistics policies at the strategic level. PMID:24977209

Determinants of Informal Employment: A Case of Tanzania's ...

African Journals Online (AJOL)

industry. A Logit regression model is employed in estimating factors that influence the choice ... International Labour Organization (ILO) (2013), the informal economy ... This study uses primary data which was collected in six most vibrant urban.

The Incidence of Unemployment: Identifying Quits and Layoffs

DEFF Research Database (Denmark)

Nielsen, Helena Skyt; Rosholm, Michael

1997-01-01

We analyse what determines the incidence of unemployment among Danish employees by estimation of a logit model for becoming unemployed. Our data is incomplete in the sense that we do not observe whether a transition was caused by the person quitting or being laid off, so we apply the EM-algorithm......We analyse what determines the incidence of unemployment among Danish employees by estimation of a logit model for becoming unemployed. Our data is incomplete in the sense that we do not observe whether a transition was caused by the person quitting or being laid off, so we apply the EM......-algorithm to this problem. The models are extended to account for the panel data structure of the data set by including random effects. We use exclusion restrictions to identify quits and lay offs. We find many quitters among young and old women but only few among men....

Getting the right balance? A mixed logit analysis of the relationship between UK training doctors' characteristics and their specialties using the 2013 National Training Survey.

Science.gov (United States)

Rodriguez Santana, Idaira; Chalkley, Martin

2017-08-11

To analyse how training doctors' demographic and socioeconomic characteristics vary according to the specialty that they are training for. Descriptive statistics and mixed logistic regression analysis of cross-sectional survey data to quantify evidence of systematic relationships between doctors' characteristics and their specialty. Doctors in training in the United Kingdom in 2013. 27 530 doctors in training but not in their foundation year who responded to the National Training Survey 2013. Mixed logit regression estimates and the corresponding odds ratios (calculated separately for all doctors in training and a subsample comprising those educated in the UK), relating gender, age, ethnicity, place of studies, socioeconomic background and parental education to the probability of training for a particular specialty. Being female and being white British increase the chances of being in general practice with respect to any other specialty, while coming from a better-off socioeconomic background and having parents with tertiary education have the opposite effect. Mixed results are found for age and place of studies. For example, the difference between men and women is greatest for surgical specialties for which a man is 12.121 times more likely to be training to a surgical specialty (relative to general practice) than a woman (p-valuevalue<0.01). There are systematic and substantial differences between specialties in respect of training doctors' gender, ethnicity, age and socioeconomic background. The persistent underrepresentation in some specialties of women, minority ethnic groups and of those coming from disadvantaged backgrounds will impact on the representativeness of the profession into the future. Further research is needed to understand how the processes of selection and the self-selection of applicants into specialties gives rise to these observed differences. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article

A Joint Modeling Analysis of Passengers’ Intercity Travel Destination and Mode Choices in Yangtze River Delta Megaregion of China

Directory of Open Access Journals (Sweden)

Yanli Wang

2016-01-01

Full Text Available Joint destination-mode travel choice models are developed for intercity long-distance travel among sixteen cities in Yangtze River Delta Megaregion of China. The model is developed for all the trips in the sample and also by two different trip purposes, work-related business and personal business trips, to accommodate different time values and attraction factors. A nested logit modeling framework is applied to model trip destination and mode choices in two different levels, where the lower level is a mode choice model and the upper level is a destination choice model. The utility values from various travel modes in the lower level are summarized into a composite utility, which is then specified into the destination choice model as an intercity impedance factor. The model is then applied to predict the change in passenger number from Shanghai to Yangzhou between scenarios with and without high-speed rail service to demonstrate the applicability. It is helpful for understanding and modeling megaregional travel destination and mode choice behaviors in the context of developing country.

A fashion model with social interaction

Science.gov (United States)

Nakayama, Shoichiro; Nakamura, Yasuyuki

2004-06-01

In general, it is difficult to investigate social phenomena mathematically or quantitatively due to non-linear interactions. Statistical physics can provide powerful methods for studying social phenomena with interactions, and could be very useful for them. In this study, we take a focus on fashion as a social phenomenon with interaction. The social interaction considered here are “bandwagon effect” and “snob effect.” In the bandwagon effect, the correlation between one's behavior and others is positive. People feel fashion weary or boring when it is overly popular. This is the snob effect. It is assumed that the fashion phenomenon is formed by the aggregation of individual's binary choice, that is, the fashion is adopted or not. We formulate the fashion phenomenon as the logit model, which is based on the random utility theory in social science, especially economics. The model derived here basically has the similarity with the pioneering model by Weidlich (Phys. Rep. 204 (1991) 1), which was derived from the master equation, the Langevin equation, or the Fokker-Planck equation. This study seems to give the behavioral or behaviormetrical foundation to his model. As a result of dynamical analysis, it is found that in the case that both the bandwagon effect and the snob effect work, periodic or chaotic behavior of fashion occurs under certain conditions.

Determinants of agricultural micro-credit repayment-evidence from ...

African Journals Online (AJOL)

Agro-Science ... for the study while descriptive statistics and multinomial binary logit model were employed for data analyses. ... on long term funds (without prejudice to the existing revolving loan mechanism) such as the pension contributions, ...

The Global Financial Crisis and currency crises in Latin America

NARCIS (Netherlands)

Boonman, Tjeerd M.; Jacobs, Jan P.A.M.; Kuper, Gerard H.

2012-01-01

The Global Financial Crisis (GFC) has aected many regions including Latin America. This paper focuses on currency crises in Argentina, Brazil and Mexico. We estimate an Early Warning System, consisting of a dynamic factor model and an ordered logit model, with monthly data for 1990-2007. Ex ante

Exploring residential energy consumers' willingness to accept and pay to offset their CO2-emission

DEFF Research Database (Denmark)

Yang, Yingkui; Solgaard, Hans Stubbe

2015-01-01

to pay for carbon offset. Finally, the ordered logit model is used in modelling willing to pay for carbon offset. Findings The results show that there is significant support from residential energy consumer to offset their CO2 emission from electricity consumption. The WTP is motivated by consumers...

Multi-agent fare optimization model of two modes problem and its analysis based on edge of chaos

Science.gov (United States)

Li, Xue-yan; Li, Xue-mei; Li, Xue-wei; Qiu, He-ting

2017-03-01

This paper proposes a new framework of fare optimization & game model for studying the competition between two travel modes (high speed railway and civil aviation) in which passengers' group behavior is taken into consideration. The small-world network is introduced to construct the multi-agent model of passengers' travel mode choice. The cumulative prospect theory is adopted to depict passengers' bounded rationality, the heterogeneity of passengers' reference point is depicted using the idea of group emotion computing. The conceptions of "Langton parameter" and "evolution entropy" in the theory of "edge of chaos" are introduced to create passengers' "decision coefficient" and "evolution entropy of travel mode choice" which are used to quantify passengers' group behavior. The numerical simulation and the analysis of passengers' behavior show that (1) the new model inherits the features of traditional model well and the idea of self-organizing traffic flow evolution fully embodies passengers' bounded rationality, (2) compared with the traditional model (logit model), when passengers are in the "edge of chaos" state, the total profit of the transportation system is higher.

Metro passengers’ route choice model and its application considering perceived transfer threshold

Science.gov (United States)

Jin, Fanglei; Zhang, Yongsheng; Liu, Shasha

2017-01-01

With the rapid development of the Metro network in China, the greatly increased route alternatives make passengers’ route choice behavior and passenger flow assignment more complicated, which presents challenges to the operation management. In this paper, a path sized logit model is adopted to analyze passengers’ route choice preferences considering such parameters as in-vehicle time, number of transfers, and transfer time. Moreover, the “perceived transfer threshold” is defined and included in the utility function to reflect the penalty difference caused by transfer time on passengers’ perceived utility under various numbers of transfers. Next, based on the revealed preference data collected in the Guangzhou Metro, the proposed model is calibrated. The appropriate perceived transfer threshold value and the route choice preferences are analyzed. Finally, the model is applied to a personalized route planning case to demonstrate the engineering practicability of route choice behavior analysis. The results show that the introduction of the perceived transfer threshold is helpful to improve the model’s explanatory abilities. In addition, personalized route planning based on route choice preferences can meet passengers’ diversified travel demands. PMID:28957376

A biclustering algorithm for binary matrices based on penalized Bernoulli likelihood

KAUST Repository

Lee, Seokho; Huang, Jianhua Z.

2013-01-01

We propose a new biclustering method for binary data matrices using the maximum penalized Bernoulli likelihood estimation. Our method applies a multi-layer model defined on the logits of the success probabilities, where each layer represents a

Modelling parking behaviour considering heterogeneity

Energy Technology Data Exchange (ETDEWEB)

San Martin, G.A.; Ibeas Portilla, A.; Alonso Oreña, B.; Olio, L. del

2016-07-01

Most of motorized trips in cities of middle and small size are made in public transport and mainly in private vehicle, this has caused a saturation in parking systems of the cities, causing important problems to society, one of the most important problems is high occupancy of public space by parking systems. Thus, is required the estimation of models that reproduce users’ behaviour when they are choosing for parking in cities, to carry out transport policies to improve transport efficiency and parking systems in the cities. The aim of this paper is the specification and estimation of models that simulate users’ behaviour when they are choosing among alternatives of parking that there are in the city: free on street parking, paid on street parking, paid on underground parking and Park and Ride (now there isn´t). For this purpose, is proposed a multinomial logit model that consider systematic and random variations in tastes. Data of users’ behaviour from the different alternatives of parking have been obtained with a stated preference surveys campaign which have been done in May 2015 in the principal parking zones of the city of Santander. In this paper, we provide a number of improvements to previously developed methodologies because of we consider much more realism to create the scenarios stated preference survey, obtaining better adjustments. (Author)

Winter weather demand considerations.

Science.gov (United States)

2015-04-01

Winter weather has varied effects on travel behavior. Using 418 survey responses from the Northern Virginia : commuting area of Washington, D.C. and binary logit models, this study examines travel related changes under : different types of winter wea...

A metric for cross-sample comparisons using logit and probit

DEFF Research Database (Denmark)

Karlson, Kristian Bernt

relative to an arbitrary scale, which makes the coefficients difficult both to interpret and to compare across groups or samples. Do differences in coefficients reflect true differences or differences in scales? This cross-sample comparison problem raises concerns for comparative research. However, we......* across groups or samples, making it suitable for situations met in real applications in comparative research. Our derivations also extend to the probit and to ordered and multinomial models. The new metric is implemented in the Stata command nlcorr....

Explaining food insecurity among indigenous households of the Sierra Tarahumara in the Mexican state of Chihuahua

Energy Technology Data Exchange (ETDEWEB)

Cordero-Ahiman, O.V.; Santellano-Estrada, E.; Garrido, A.

2017-09-01

Numerous studies have analyzed the factors that determine food security and explored the problem from regional or national points of view. However, there has been less research targeting an understanding of the food security problem at the household level in specific rural locations like indigenous communities. Indigenous groups are recognized as priority groups in Mexico, because they live in a situation of poverty. For this reason, the objective of this research was to investigate the determinants of food insecurity among the indigenous communities of the Sierra Tarahumara in Mexico. We used the Latin American and Caribbean Household Food Security Measurement Scale (ELCSA). This scale is useful for measuring food insecurity levels in households. A questionnaire was administered to 123 households. We employed the method based on Cronbach's alpha to measure internal consistency, which was 0.96. In addition, we estimated the main determinants of household food insecurity using both ordered logit model and binomial logit model. We found that approximately 59.35% of households were living in a situation of severe food insecurity. The two predictive models applied suggest that: i) income is the most important determinant of access to food; ii) increased maize production improves food security; iii) farmers consume their seed stocks in times of food scarcity, and iv) households are food insecure when the householders are in casual employment. Akaike's information criterion and the Bayesian information criterion suggest that the goodness of fit to the data was better for the ordered logit model.

People's Risk Recognition Preceding Evacuation and Its Role in Demand Modeling and Planning.

Science.gov (United States)

Urata, Junji; Pel, Adam J

2018-05-01

Evacuation planning and management involves estimating the travel demand in the event that such action is required. This is usually done as a function of people's decision to evacuate, which we show is strongly linked to their risk awareness. We use an empirical data set, which shows tsunami evacuation behavior, to demonstrate that risk recognition is not synonymous with objective risk, but is instead determined by a combination of factors including risk education, information, and sociodemographics, and that it changes dynamically over time. Based on these findings, we formulate an ordered logit model to describe risk recognition combined with a latent class model to describe evacuation choices. Our proposed evacuation choice model along with a risk recognition class can evaluate quantitatively the influence of disaster mitigation measures, risk education, and risk information. The results obtained from the risk recognition model show that risk information has a greater impact in the sense that people recognize their high risk. The results of the evacuation choice model show that people who are unaware of their risk take a longer time to evacuate. © 2017 Society for Risk Analysis.

Reconsidering the use of rankings in the valuation of health states: a model for estimating cardinal values from ordinal data

Directory of Open Access Journals (Sweden)

Salomon Joshua A

2003-12-01

Full Text Available Abstract Background In survey studies on health-state valuations, ordinal ranking exercises often are used as precursors to other elicitation methods such as the time trade-off (TTO or standard gamble, but the ranking data have not been used in deriving cardinal valuations. This study reconsiders the role of ordinal ranks in valuing health and introduces a new approach to estimate interval-scaled valuations based on aggregate ranking data. Methods Analyses were undertaken on data from a previously published general population survey study in the United Kingdom that included rankings and TTO values for hypothetical states described using the EQ-5D classification system. The EQ-5D includes five domains (mobility, self-care, usual activities, pain/discomfort and anxiety/depression with three possible levels on each. Rank data were analysed using a random utility model, operationalized through conditional logit regression. In the statistical model, probabilities of observed rankings were related to the latent utilities of different health states, modeled as a linear function of EQ-5D domain scores, as in previously reported EQ-5D valuation functions. Predicted valuations based on the conditional logit model were compared to observed TTO values for the 42 states in the study and to predictions based on a model estimated directly from the TTO values. Models were evaluated using the intraclass correlation coefficient (ICC between predictions and mean observations, and the root mean squared error of predictions at the individual level. Results Agreement between predicted valuations from the rank model and observed TTO values was very high, with an ICC of 0.97, only marginally lower than for predictions based on the model estimated directly from TTO values (ICC = 0.99. Individual-level errors were also comparable in the two models, with root mean squared errors of 0.503 and 0.496 for the rank-based and TTO-based predictions, respectively. Conclusions

Valuing energy-saving measures in residential buildings. A choice experiment study

Energy Technology Data Exchange (ETDEWEB)

Kwak, So-Yoon; Kwak, Seung-Jun [Department of Economics, Korea University, 5-1 Anam-Dong, Seoul 136-701 (Korea); Yoo, Seung-Hoon [Department of International Area Studies, Hoseo University, 268 Anseo-Dong, Cheonan, Chungnam 330-713 (Korea)

2010-01-15

Air-conditioning and heating energy-saving measures can cut back the usage of energy. This paper attempts to apply a choice experiment in evaluating the consumer's willingness to pay (WTP) for air-conditioning and heating energy-saving measures in Korea's residential buildings. We consider the trade-offs between price and three attributes of energy-saving (window, facade, and ventilation) for selecting a preferred alternative and derive the marginal WTP (MWTP) estimate for each attribute. We also try to test irrelevant alternatives property for the estimation model holds and compare the estimation results of the multinomial logit (MNL) and the nested logit (NL) models. The NL model outperforms the MNL model. The NL model show that MWTPs for increasing the number of glasses and their variety, for increasing the thickness of facade for 1 mm, and for establishing a ventilation system are KRW 17,392 (USD 18.2), 1,112 (1.2), and 11,827 (12.4), respectively. Overall, the potential consumers have significant amount of WTP. (author)

Energy consumption and economic growth—New evidence from meta analysis

International Nuclear Information System (INIS)

Chen, Ping-Yu; Chen, Sheng-Tung; Chen, Chi-Chung

2012-01-01

The causal relationships between energy consumption and economic growth have given rise to much discussion but remain controversial. Alternative data sets based on different time spans, countries, energy policies and econometric approaches result in diverse outcomes. A meta analysis using a multinomial logit model with 174 samples governing the relationships between GDP and energy consumption is applied here to investigate the major factors that affect these controversial outcomes. The empirical results have demonstrated how the time spans, subject selections including GDP and energy consumption, econometric models, and tools for greenhouse gases emission reduction characteristics significantly affect these controversial outcomes. - Highlights: ► The controversial casual relationships between energy consumption and GDP are investigated. ► A meta analysis using a multinomial logit model is adopted. ► 74 studies governing the relationships between GDP and energy consumption was collected. ► The empirical results show how the probability of major factors affects such relationships.

Evaluating the market splitting determinants: evidence from the Iberian spot electricity prices

International Nuclear Information System (INIS)

Figueiredo, Nuno Carvalho; Silva, Patrícia Pereira da; Cerqueira, Pedro A.

2015-01-01

This paper aims to assess the main determinants on the market splitting behaviour of the Iberian electricity spot markets. Iberia stands as an ideal case-study, where the high level deployment of wind power is observed, together with the implementation of the market splitting arrangement between the Portuguese and the Spanish spot electricity markets. Logit and non-parametric models are used to express the probability response for market splitting of day-ahead spot electricity prices as a function of the explanatory variables representing the main technologies in the generation mix: wind, hydro, thermal and nuclear power, together with the available transfer capacity and electricity demand. Logit models give preliminary indications about market splitting behaviour, and then, notwithstanding the demanding computational challenge, a non-parametric model is applied in order to overcome the limitations of the former models. Results show an increase of market splitting probability with higher wind power generation or, more generally, with higher availability of low marginal cost electricity such as nuclear power generation. The European interconnection capacity target of 10% of the peak demand of the smallest interconnected market might be insufficient to maintain electricity market integration. Therefore, pro-active coordination policies, governing both interconnections and renewables deployment, should be further developed. -- Highlights: •Assess determinants on market splitting behaviour of Iberian electricity markets. •Logit and non-parametric models to express market splitting probability response. •Explanatory variables: wind, hydro, thermal and nuclear power; ATC and demand. •Results: increase of market splitting probability with higher availability of low marginal cost electricity. •Coordination policies governing both interconnections and renewables deployment

Facet-based analysis of vacation planning process : a binary mixed logit panel model

NARCIS (Netherlands)

Grigolon, A.B.; Kemperman, A.D.A.M.; Timmermans, H.J.P.

2013-01-01

This article documents the design and results of a study on vacation planning processes with a particular focus on aggregate relationships between the probability that a certain facet of the vacation decision has been decided at a particular point in time, as a function of lead time to the actual

Facet-based analysis of vacation planning processes : a binary mixed logit panel model

NARCIS (Netherlands)

Grigolon, Anna; Kemperman, Astrid; Timmermans, Harry

2012-01-01

This article documents the design and results of a study on vacation planning processes with a particular focus on aggregate relationships between the probability that a certain facet of the vacation decision has been decided at a particular point in time, as a function of lead time to the actual

Reasons for not buying a car : a probit-selection multinomial logit choice model

NARCIS (Netherlands)

Gao, Y.; Rasouli, S.; Timmermans, H.J.P.

2014-01-01

Generating and maintaining gradients of cell density and extracellular matrix (ECM) components is a prerequisite for the development of functionality of healthy tissue. Therefore, gaining insights into the drivers of spatial organization of cells and the role of ECM during tissue morphogenesis is

Physics and financial economics (1776-2014): puzzles, Ising and agent-based models

Science.gov (United States)

Sornette, Didier

2014-06-01

This short review presents a selected history of the mutual fertilization between physics and economics—from Isaac Newton and Adam Smith to the present. The fundamentally different perspectives embraced in theories developed in financial economics compared with physics are dissected with the examples of the volatility smile and of the excess volatility puzzle. The role of the Ising model of phase transitions to model social and financial systems is reviewed, with the concepts of random utilities and the logit model as the analog of the Boltzmann factor in statistical physics. Recent extensions in terms of quantum decision theory are also covered. A wealth of models are discussed briefly that build on the Ising model and generalize it to account for the many stylized facts of financial markets. A summary of the relevance of the Ising model and its extensions is provided to account for financial bubbles and crashes. The review would be incomplete if it did not cover the dynamical field of agent-based models (ABMs), also known as computational economic models, of which the Ising-type models are just special ABM implementations. We formulate the ‘Emerging Intelligence Market Hypothesis’ to reconcile the pervasive presence of ‘noise traders’ with the near efficiency of financial markets. Finally, we note that evolutionary biology, more than physics, is now playing a growing role to inspire models of financial markets.

Physics and financial economics (1776-2014): puzzles, Ising and agent-based models.

Science.gov (United States)

Sornette, Didier

2014-06-01

This short review presents a selected history of the mutual fertilization between physics and economics--from Isaac Newton and Adam Smith to the present. The fundamentally different perspectives embraced in theories developed in financial economics compared with physics are dissected with the examples of the volatility smile and of the excess volatility puzzle. The role of the Ising model of phase transitions to model social and financial systems is reviewed, with the concepts of random utilities and the logit model as the analog of the Boltzmann factor in statistical physics. Recent extensions in terms of quantum decision theory are also covered. A wealth of models are discussed briefly that build on the Ising model and generalize it to account for the many stylized facts of financial markets. A summary of the relevance of the Ising model and its extensions is provided to account for financial bubbles and crashes. The review would be incomplete if it did not cover the dynamical field of agent-based models (ABMs), also known as computational economic models, of which the Ising-type models are just special ABM implementations. We formulate the 'Emerging Intelligence Market Hypothesis' to reconcile the pervasive presence of 'noise traders' with the near efficiency of financial markets. Finally, we note that evolutionary biology, more than physics, is now playing a growing role to inspire models of financial markets.

Modelling modal shift due to the enhanced level of bus service

Directory of Open Access Journals (Sweden)

P. Vedagiri

2009-06-01

Full Text Available This study is concerned with the estimation of the probable shift of auto-rickshaw (three wheeled motorized para-transit vehicle users to the bus due to an increase in its level of service after providing exclusive bus lanes on Indian city roads carrying heterogeneous traffic. The quantum of an increase in the level of bus service due to the introduction of an exclusive bus lane was determined using a recently developed simulation model of heterogeneous traffic flow. The data on other factors (variables that might cause modal shift from the auto-rickshaw to the bus was collected conducting a home-interview survey based on the stated preference approach. A binary logit model of mode-choice was then calibrated using the collected data and the model was also validated using a holdout sample. A mode-choice probability curve to depict the possible shift of auto-rickshaw users to the bus is developed taking difference in the travel times of two-modes as the basis to serve as a user friendly tool to analyze the possible modal shift for a wide range of the values of the involved variables.

A Multinomial Logit Approach to Estimating Regional Inventories by Product Class

Science.gov (United States)

Lawrence Teeter; Xiaoping Zhou

1998-01-01

Current timber inventory projections generally lack information on inventory by product classes. Most models available for inventory projection and linked to supply analyses are limited to projecting aggregate softwood and hardwood. The objective of this research is to develop a methodology to distribute the volume on each FIA survey plot to product classes and...

Dutch Consumers’ Willingness to Pay for Broiler Welfare

NARCIS (Netherlands)

Mulder, Machiel; Zomer, Sigourney

2017-01-01

This article analyzes Dutch consumers’ willingness to pay (WTP) for the welfare of broiler chickens and the consequences for nonhuman animal welfare policies. Using data from a discrete-choice experiment and a random parameter logit model, this study showed that consumers particularly value

Users evaluation of transport mode characteristics with special attention to public transport

NARCIS (Netherlands)

Waerden, van der P.J.H.J.; Borgers, A.W.J.; Timmermans, H.J.P.; Berenos, M.

2007-01-01

The paper focuses on the influence of public transport use on the evaluation of transport mode characteristics. Based on stated choice data, several multinomial logit models that include parameters representing differences between users and non-users of public transport are estimated. The estimation

Single toxin dose-response models revisited

Energy Technology Data Exchange (ETDEWEB)

Demidenko, Eugene, E-mail: eugened@dartmouth.edu [Department of Biomedical Data Science, Geisel School of Medicine at Dartmouth, Hanover, NH03756 (United States); Glaholt, SP, E-mail: sglaholt@indiana.edu [Indiana University, School of Public & Environmental Affairs, Bloomington, IN47405 (United States); Department of Biological Sciences, Dartmouth College, Hanover, NH03755 (United States); Kyker-Snowman, E, E-mail: ek2002@wildcats.unh.edu [Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH03824 (United States); Shaw, JR, E-mail: joeshaw@indiana.edu [Indiana University, School of Public & Environmental Affairs, Bloomington, IN47405 (United States); Chen, CY, E-mail: Celia.Y.Chen@dartmouth.edu [Department of Biological Sciences, Dartmouth College, Hanover, NH03755 (United States)

2017-01-01

The goal of this paper is to offer a rigorous analysis of the sigmoid shape single toxin dose-response relationship. The toxin efficacy function is introduced and four special points, including maximum toxin efficacy and inflection points, on the dose-response curve are defined. The special points define three phases of the toxin effect on mortality: (1) toxin concentrations smaller than the first inflection point or (2) larger then the second inflection point imply low mortality rate, and (3) concentrations between the first and the second inflection points imply high mortality rate. Probabilistic interpretation and mathematical analysis for each of the four models, Hill, logit, probit, and Weibull is provided. Two general model extensions are introduced: (1) the multi-target hit model that accounts for the existence of several vital receptors affected by the toxin, and (2) model with a nonzero mortality at zero concentration to account for natural mortality. Special attention is given to statistical estimation in the framework of the generalized linear model with the binomial dependent variable as the mortality count in each experiment, contrary to the widespread nonlinear regression treating the mortality rate as continuous variable. The models are illustrated using standard EPA Daphnia acute (48 h) toxicity tests with mortality as a function of NiCl or CuSO{sub 4} toxin. - Highlights: • The paper offers a rigorous study of a sigmoid dose-response relationship. • The concentration with highest mortality rate is rigorously defined. • A table with four special points for five morality curves is presented. • Two new sigmoid dose-response models have been introduced. • The generalized linear model is advocated for estimation of sigmoid dose-response relationship.

A Comparison of Alternative Specifications of the College Attendance Equation with an Extension to two-stage Selectivity-Correction Models.

Science.gov (United States)

Hilmer, Michael J.

2001-01-01

Estimates a college-attendance equation for a common set of students (from the High School and Beyond Survey) using three popular econometric specifications: the multinomial logit, the ordered probit, and the bivariate probit. Estimated marginal effects do not differ significantly across the three specifications. Choice of specification may not…

Physics and financial economics (1776–2014): puzzles, Ising and agent-based models

International Nuclear Information System (INIS)

Sornette, Didier

2014-01-01

This short review presents a selected history of the mutual fertilization between physics and economics—from Isaac Newton and Adam Smith to the present. The fundamentally different perspectives embraced in theories developed in financial economics compared with physics are dissected with the examples of the volatility smile and of the excess volatility puzzle. The role of the Ising model of phase transitions to model social and financial systems is reviewed, with the concepts of random utilities and the logit model as the analog of the Boltzmann factor in statistical physics. Recent extensions in terms of quantum decision theory are also covered. A wealth of models are discussed briefly that build on the Ising model and generalize it to account for the many stylized facts of financial markets. A summary of the relevance of the Ising model and its extensions is provided to account for financial bubbles and crashes. The review would be incomplete if it did not cover the dynamical field of agent-based models (ABMs), also known as computational economic models, of which the Ising-type models are just special ABM implementations. We formulate the ‘Emerging Intelligence Market Hypothesis’ to reconcile the pervasive presence of ‘noise traders’ with the near efficiency of financial markets. Finally, we note that evolutionary biology, more than physics, is now playing a growing role to inspire models of financial markets. (key issues reviews)

Forest resources, government policy, and investment location decisions of the forest products industry in the southern United States

Science.gov (United States)

Changyou Sun; Daowei Zhang

2010-01-01

In this article, the results of an initial attempt to estimate the effects of state attributes on plant location and investment expenditure were presented for the forest products industry in the southern United States. A conditional logit model was used to analyze new plant births, and a time-series cross-section model to assess the total capital expenditure....

Ordering the preference hierarchies for internal finance, bank laons, bond and share issue: evidence from Dutch firms

NARCIS (Netherlands)

de Haan, L.; Hinloopen, J.

2003-01-01

We estimate the incremental financing decision for a sample of some 150 Dutch companies for the years 1984 through 1997, thereby distinguishing internal finance and three types of external finance: bank borrowing, bond issues, and share issues. First, we estimate a multinomial logit model, which

The joint choice of tenure, dwelling type, size and location: the effect of home-oriented versus culture-oriented lifestyle

DEFF Research Database (Denmark)

Frenkel, Amnon; Kaplan, Sigal

2014-01-01

This study investigates knowledge-workers’ housing preferences in terms of tenure, dwelling type, location and size. The analysis is conducted by applying a joint multinomial-logit ordered-response model to the housing choices of knowledgeworkers residing in the Tel-Aviv metropolitan region and w...

Patterns and correlates of solid waste disposal practices in Dar es ...

African Journals Online (AJOL)

This study examines the patterns and correlations of solid waste disposal practices among households in urbanized and populated Dar es Salaam city in Tanzania. The Tanzanian Household Budget Survey (HBS) data covering many households' characteristics was used. Multinomial Logit (MNL) model was applied to ...

Assessing farmer involvement in collective action for enhancing the ...

African Journals Online (AJOL)

Assessing farmer involvement in collective action for enhancing the sorghum value chain in Soroti, Uganda. ... in six sub-counties of Soroti, Uganda, where associations are established. A binomial logit regression model was employed to ascertain socio-economic factors that influenced membership to farmer associations.

Spatial occupancy models for large data sets

Science.gov (United States)

Johnson, Devin S.; Conn, Paul B.; Hooten, Mevin B.; Ray, Justina C.; Pond, Bruce A.

2013-01-01

Since its development, occupancy modeling has become a popular and useful tool for ecologists wishing to learn about the dynamics of species occurrence over time and space. Such models require presence–absence data to be collected at spatially indexed survey units. However, only recently have researchers recognized the need to correct for spatially induced overdisperison by explicitly accounting for spatial autocorrelation in occupancy probability. Previous efforts to incorporate such autocorrelation have largely focused on logit-normal formulations for occupancy, with spatial autocorrelation induced by a random effect within a hierarchical modeling framework. Although useful, computational time generally limits such an approach to relatively small data sets, and there are often problems with algorithm instability, yielding unsatisfactory results. Further, recent research has revealed a hidden form of multicollinearity in such applications, which may lead to parameter bias if not explicitly addressed. Combining several techniques, we present a unifying hierarchical spatial occupancy model specification that is particularly effective over large spatial extents. This approach employs a probit mixture framework for occupancy and can easily accommodate a reduced-dimensional spatial process to resolve issues with multicollinearity and spatial confounding while improving algorithm convergence. Using open-source software, we demonstrate this new model specification using a case study involving occupancy of caribou (Rangifer tarandus) over a set of 1080 survey units spanning a large contiguous region (108 000 km2) in northern Ontario, Canada. Overall, the combination of a more efficient specification and open-source software allows for a facile and stable implementation of spatial occupancy models for large data sets.

SEARCHING THE FACTORS HAVING CREDIT CARD: A SURVEY STUDY IN ERZURUM

Directory of Open Access Journals (Sweden)

ERKAN OKTAY

2013-06-01

Full Text Available In this study, the factors related with having credit card in Erzurum have been searched by a logit model. There are demographic, social, cultural, and economic variables in the model. The final model is statistically significant. According to the model, job, average household income per month, payment method at shopping, usefulness of credit card and increasing the shopping tendency are statistically significant on having credit card.

The Formation of Model Assembly on the Basis of Specialization of Experts for Classification of Borrowers – Natural Entities

Directory of Open Access Journals (Sweden)

Ben Vladyslav P.

2018-01-01

Full Text Available The article is aimed at researching the efficiency of the use of assembly technologies to solve the task of classifying borrowers – natural entities in relation to the level of credit risk. Features of information support of the process of solving the task of classifying borrowers – natural entities were analyzed. The necessity of application of model assemblies as one of contemporary directions of processing of big data has been substantiated. The author’s own variant of algorithm of creation of an assembly on the basis of specialization of separate models-experts has been provided. The proposed approach is implemented in two versions according to the types of models used as experts. In the first variant the assembly consists of logit-regressions, in the second variant – of neural networks. An analysis of the obtained results has proved that the described assembly structure gives an opportunity to increase the accuracy of assessment of the credit risks of borrowers, and it is expedient to use neural networks as separate models-experts.

Modeling the Perceptions and Preferences of Pedestrians on Crossing Facilities

Directory of Open Access Journals (Sweden)

Hongwei Guo

2014-01-01

Full Text Available Pedestrian’s street-crossing behaviour has a significant effect on traffic performance and safety. The crossing behaviour is determined by human factors and environmental factors. Aiming at examining the pedestrian perceptions toward crossing facilities and preferences for crossing locations, an observational study of pedestrian crossing behaviour at urban street is conducted. The perceptions and preferences of pedestrians are collected using stated preference technique. A specific questionnaire is designed to conduct the stated preference survey. A multinomial logit model is proposed to describe the perceptions and preferences of pedestrians on crossing facilities and locations. The sensitivity analysis is performed to discuss the influence of various factors on crossing behaviour. Then the relationship between crossing locations and crossing distances is analyzed by a new proposed method. With the theoretical analysis, the engineering solutions considering pedestrian behaviour are suggested. The results are helpful to design human-centered crossing facilities in urban traffic.

Animal welfare and eggs - cheap talk or money on the counter?

DEFF Research Database (Denmark)

Andersen, Laura Mørch

2011-01-01

Our estimate revealed willingness to pay for animal welfare using a panel mixed logit model. We utilise a unique household level panel, combining real purchases with survey data on perceived public and private good attributes of different types of eggs. We estimate willingness to pay for organic...

Multidimensional Computerized Adaptive Testing for Indonesia Junior High School Biology

Science.gov (United States)

Kuo, Bor-Chen; Daud, Muslem; Yang, Chih-Wei

2015-01-01

This paper describes a curriculum-based multidimensional computerized adaptive test that was developed for Indonesia junior high school Biology. In adherence to the Indonesian curriculum of different Biology dimensions, 300 items was constructed, and then tested to 2238 students. A multidimensional random coefficients multinomial logit model was…

Experimental investigation of consumer price evaluations

NARCIS (Netherlands)

Z. Sándor (Zsolt); Ph.H.B.F. Franses (Philip Hans)

2004-01-01

textabstractWe develop a procedure to collect experimental choice data for estimating consumer preferences with a special focus on consumer price evaluations. For this purpose we employ a heteroskedastic mixed logit model that measures the effect of the way prices are specified on the variance of

Relating cost-benefit analysis results with transport project decisions in the Netherlands

NARCIS (Netherlands)

Annema, Jan Anne; Frenken, Koen|info:eu-repo/dai/nl/207145253; Koopmans, Carl; Kroesen, Maarten

2017-01-01

This paper relates the cost-benefit analysis (CBA) results of transportation policy proposals in the Netherlands with the decision to implement or abandon the proposal. The aim of this study is to explore the relation between the CBA results and decision-making. Multinomial logit regression models

The determinants of the location of foreign direct investment in UK regions

NARCIS (Netherlands)

Dimitropoulou, Dimitra; McCann, Philip; Burke, Simon P.

2013-01-01

This article employs a database of over 2000 observations of Foreign Direct Investment (FDI) projects in UK regions. We analyse this data by means of various multinomial and conditional logit models in order to identify the major determinants of the location choices of these inward investments.

Entrepreneurial engagement levels in the European Union

NARCIS (Netherlands)

I. Grilo (Isabel); A.R. Thurik (Roy)

2005-01-01

textabstractA multinomial logit model and survey data from the 25 EU member states and the US are used to establish the effect of demographic and other variables on various entrepreneurial engagement levels. These engagement levels range from never thought about starting a business to thinking

[A photographic scale for evaluating facial pores and analysis of factors associated with pore widening in Chengdu].

Science.gov (United States)

Wang, Qing; Zhou, Cheng-xia; Meng, Hui-min; Wang, Xi; Li, Li

2010-09-01

To develop a photographic scale for grading widening of pores, and to identify the factors associated with pore widening. People with widened pores were recruited, with photographs taken on their nasal tips, nasal alas and cheeks. A questionnaire survey was undertaken by dermatologists to assess the severity of pore widening. A Cumulative Logit Model was established to identify factors that were associated with pore widening. A total of 115 people participated in the study and 562 photographs were taken. The photographic scale was highly consistent with the clinical judgment. Another 1011 residents aged from 18 to 70 years old in Chengdu were surveyed. The logit model revealed that facial pore widening were associated with gender, age, oily skin, sun protection and anti-aging cosmetic. The photographic scale is reliable and easy to use. Gender, age and oily skin are risk factors, and sun protection and anti-aging cosmetic are protective factors with related to pore widening.

Strategies of Market Development of for Healthy Food Products in Hamadan

Directory of Open Access Journals (Sweden)

vahid Azizi

2014-03-01

Full Text Available This study was conducted at the aim of determining development strategies for marketing healthy food products. The study data was collected by conducting field survey and compeleting a questionnaire. Using simple random sampling, about 400 Hamedan citizens were selected in 2013. The data analysis was conducted by ordinal Logit model with method of maximum Likelihood. According to the results, 32 percent of people do not tend to shopping healthy food products, 34.3 percent of people ignored shopping of healthy food products, 33.8 percent of them tend to shopping of healthy food products. The results of estimating the ordinal Logit model presented that strategies such as cognition indicators, environment lover, Advertising and Information, Education, Supportive and monitoring facilities, structural and Service facilities and economic indicator should be considered as marketing strategies to develop healthy food products. In order to develop the healthy food market, the long term programs in the three sectors of products, consumption and marketing should be considered from specific purposes.

Human capital accumulation and its effect on agribusiness performance: the case of China.

Science.gov (United States)

Udimal, Thomas Bilaliib; Jincai, Zhuang; Ayamba, Emmanuel Caesar; Sarpong, Patrick Boateng

2017-09-01

This study investigates the effect of accumulated human capital on the performance of agribusinesses in China. Four hundred fifty agribusiness owners were interviewed for the study. Growth in sales over the last 5 years was used as a measure of performance. The following variables were reviewed and captured as those constituting human capital: education, raised in the area, parents being entrepreneurs, attending business seminars/trade fairs, managerial experience, similar work experience, cooperative membership, and training. Logit regression model and inferential statistics were used to analyze the data. The logit regression model was used to analyze the effect of accumulated human capital on growth in sales. The inferential statistics on the other hand was used to measure the association between age, education, sex, provinces, and the categories of growth. Our study found that parents who are entrepreneurs and attend business seminars/trade fairs, as well as have managerial experience, similar work experience, education, and training, display a statistically significant positive effect on the growth in sales.

An assessment of econometric models applied to fossil fuel power generation; Un'analisi critica dell'applicazione dei modelli econometrici alla generazione termoelettrica

Energy Technology Data Exchange (ETDEWEB)

Gracceva, F.; Quercioli, R. [ENEA, Funzione Centrale Studi, Centro Ricerche Casaccia, Rome (Italy)

2001-07-01

The main purpose of this report is to provide a general view of those studies, in which the econometric approach is applied to the selection of fuel in fossil fired power generation, focusing the attention to the key role played by the fuel prices. The report consists of a methodological analysis and a survey of the studies available in literature. The methodological analysis allows to assess the adequateness of the econometric approach, in the electrical power utilities policy. With this purpose, the fundamentals of microeconomics, which are the basis of the econometric models, are pointed out and discussed, and then the hypotheses, which are needed to be assumed for complying the economic theory, are verified in their actual implementation in the power generation sector. The survey of the available studies provides a detailed description of the Translog and Logit models, and the results achieved with their application. From these results, the estimated models show to fit the data with good approximation, a certain degree of interfuel substitution and a meaningful reaction to prices on demand side. [Italian] In questo rapporto viene tracciato un quadro generale degli studi che utilizzano modelli econometrici per analizzare la scelta dei combustibili nella termogenerazione, con particoalre attenzione al ruolo svolto dal prezzo dei combustibili. La trattazione si compone di un'analisi di tipo metodologico e di una rassegna della letteratura. L'analisi metodologica consente di valutare l'adeguatezza dell'approccio econometrico nell'analisi del comportamento delle imprese di generazione elettrica. A tal fine vengono esplicitati e discussi i fondamenti microeconomici su cui poggiano i modelli econometrici, e viene verificata la sussistenza, nel settore termoelettrico, delle ipotesi che e' necessario assumere per soddisfare la teoria economica. La rassegna fornisce invece una descrizione dei modelli translog e logit lineare, ed un

The MDI Method as a Generalization of Logit, Probit and Hendry Analyses in Marketing.

Science.gov (United States)

1980-04-01

model involves nothing more than fitting a normal distribution function ( Hanushek and Jackson (1977)). For a given value of x, the probit model...preference shifts within the soft drink category. --For applications of probit models relevant for marketing, see Hausman and Wise (1978) and Hanushek and...Marketing Research" JMR XIV, Feb. (1977). Hanushek , E.A., and J.E. Jackson, Statistical Methods for Social Scientists. Academic Press, New York (1977

Determinants of Anabolic-Androgenic Steroid Risk Perceptions in Youth Populations: A Multivariate Analysis

Science.gov (United States)

Denham, Bryan E.

2009-01-01

Grounded conceptually in social cognitive theory, this research examines how personal, behavioral, and environmental factors are associated with risk perceptions of anabolic-androgenic steroids. Ordinal logistic regression and logit log-linear models applied to data gathered from high-school seniors (N = 2,160) in the 2005 Monitoring the Future…

Has the Euro Affected the Choice of Invoicing Currency?

NARCIS (Netherlands)

Ligthart, J.E.; Werner, S.E.V.

2010-01-01

We present a new approach to study empirically the effect of the introduction of the euro on currency invoicing. Our approach uses a compositional multinomial logit model, in which currency choice depends on the characteristics of both the currency and the country. We use unique quarterly panel data

Farmers' Willingness to Pay for Private Irrigation Supply in Nandom ...

African Journals Online (AJOL)

This study investigated farmers willingness to pay (WTP) for private irrigation in Nandom district, Ghana. The study randomly sampled 236 farmers and analyzed data using descriptive statistics and ordered logit regression model. Results revealed that 94.5 percent of the farmers were WTP for private irrigation services with ...

Factors Affecting Chinese Farmers' Decisions to Adopt a Water-Saving Technology

NARCIS (Netherlands)

Herzfeld, T.; Glauben, T.; Zhang, Y.; Hu, B.

2008-01-01

Chinese farm households (N = 240) were interviewed to understand some of the factors affecting their adoption of a water-saving technology called the Ground Cover Rice Production System (GCRPS). A logit model was established on the basis of a survey to estimate the determinants of adoption and to

On price equilibrium with multi-product firms

NARCIS (Netherlands)

Z. Sándor (Zsolt)

2004-01-01

textabstractIn this paper we provide a result that shows existence and uniqueness of Nash equilibrium in cases in which existent methods are problematic to apply. We employ this result to the model with simple logit demand, and show existence and uniqueness of price equilibrium when firms produce

Heterogeneity in urban park use of aging visitors: a latent class analysis

NARCIS (Netherlands)

Kemperman, A.D.A.M.; Timmermans, H.J.P.

2006-01-01

This study describes and predicts urban parks use patterns for various age groups, with specific attention to the growing group of older adults. Park use intensity of various age groups is described. Subsequently, a multinomial logit model is estimated to describe urban park choice as a function of

Mobility in the Urban Labor Market : A Panel Data Analysis for Mexico

NARCIS (Netherlands)

Gong, X.; van Soest, A.H.O.; Villagomez, E.

2000-01-01

We analyze mobility in urban Mexico between three labor market states: working in the formal sector, working in the informal sector, and not working. We use a dynamic multinomial logit panel data model with random effects, explaining the labor market state of each individual during each time period.

Environmental income improves household-level poverty assessments and dynamics

DEFF Research Database (Denmark)

Walelign, Solomon Zena; Charlery, Lindy Callen; Smith-Hall, Carsten

2016-01-01

Household-level poverty assessments and analyses of poverty dynamics in developing countries typically do not include environmental income. Using household (n = 427 in 2006, 2009 and 2012) total income panel data sets, with and without environmental income, from Nepal, we analysed the importance...... of environmental income in household-level poverty assessments (Foster-Greer-Thorbecke indices) and dynamics (movements in the Poverty Transition Matrix). Random effects logit and ordered logit models were applied to estimate variables covarying with poverty categories and compared for annual household incomes...... with and without environmental income. Using the without environmental income data set significantly changed the number of households classified as poor, as well as rates of movements in and out of poverty. Excluding household-level environmental income also distorted estimation of covariates of poverty incidence...

How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars. Part 1. Model structure, simulation of bounded rationality, and model validation

Energy Technology Data Exchange (ETDEWEB)

Mueller, Michel G.; Haan, Peter de [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J 73.2, 8092 Zurich (Switzerland)

2009-03-15

This article presents an agent-based microsimulation capable of forecasting the effects of policy levers that influence individual choices of new passenger cars. The fundamental decision-making units are households distinguished by sociodemographic characteristics and car ownership. A two-stage model of individual decision processes is employed. In the first stage, individual choice sets are constructed using simple, non-compensatory rules that are based on previously owned cars. Second, decision makers evaluate alternatives in their individual choice set using a multi-attributive weighting rule. The attribute weights are based on a multinomial logit model for cross-country policy analysis in European countries. Additionally, prospect theory and the notion of mental accounting are used to model the perception of monetary values. The microsimulation forecasts actual market observations with high accuracy, both on the level of aggregate market characteristics as well as on a highly resolved level of distributions of market shares. The presented approach is useful for the assessment of policies that influence individual purchase decisions of new passenger cars; it allows accounting for a highly resolved car fleet and differentiated consumer segments. As a result, the complexity of incentive schemes can be represented and detailed structural changes can be investigated. (author)

How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars-Part I: Model structure, simulation of bounded rationality, and model validation

Energy Technology Data Exchange (ETDEWEB)

Mueller, Michel G. [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J 73.2, 8092 Zurich (Switzerland); Haan, Peter de [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J 73.2, 8092 Zurich (Switzerland)], E-mail: peter.dehaan@env.ethz.ch

2009-03-15

This article presents an agent-based microsimulation capable of forecasting the effects of policy levers that influence individual choices of new passenger cars. The fundamental decision-making units are households distinguished by sociodemographic characteristics and car ownership. A two-stage model of individual decision processes is employed. In the first stage, individual choice sets are constructed using simple, non-compensatory rules that are based on previously owned cars. Second, decision makers evaluate alternatives in their individual choice set using a multi-attributive weighting rule. The attribute weights are based on a multinomial logit model for cross-country policy analysis in European countries. Additionally, prospect theory and the notion of mental accounting are used to model the perception of monetary values. The microsimulation forecasts actual market observations with high accuracy, both on the level of aggregate market characteristics as well as on a highly resolved level of distributions of market shares. The presented approach is useful for the assessment of policies that influence individual purchase decisions of new passenger cars; it allows accounting for a highly resolved car fleet and differentiated consumer segments. As a result, the complexity of incentive schemes can be represented and detailed structural changes can be investigated.

How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars-Part I: Model structure, simulation of bounded rationality, and model validation

International Nuclear Information System (INIS)

Mueller, Michel G.; Haan, Peter de

2009-01-01

This article presents an agent-based microsimulation capable of forecasting the effects of policy levers that influence individual choices of new passenger cars. The fundamental decision-making units are households distinguished by sociodemographic characteristics and car ownership. A two-stage model of individual decision processes is employed. In the first stage, individual choice sets are constructed using simple, non-compensatory rules that are based on previously owned cars. Second, decision makers evaluate alternatives in their individual choice set using a multi-attributive weighting rule. The attribute weights are based on a multinomial logit model for cross-country policy analysis in European countries. Additionally, prospect theory and the notion of mental accounting are used to model the perception of monetary values. The microsimulation forecasts actual market observations with high accuracy, both on the level of aggregate market characteristics as well as on a highly resolved level of distributions of market shares. The presented approach is useful for the assessment of policies that influence individual purchase decisions of new passenger cars; it allows accounting for a highly resolved car fleet and differentiated consumer segments. As a result, the complexity of incentive schemes can be represented and detailed structural changes can be investigated

Development of discrete choice model considering internal reference points and their effects in travel mode choice context

Science.gov (United States)

Sarif; Kurauchi, Shinya; Yoshii, Toshio

2017-06-01

In the conventional travel behavior models such as logit and probit, decision makers are assumed to conduct the absolute evaluations on the attributes of the choice alternatives. On the other hand, many researchers in cognitive psychology and marketing science have been suggesting that the perceptions of attributes are characterized by the benchmark called “reference points” and the relative evaluations based on them are often employed in various choice situations. Therefore, this study developed a travel behavior model based on the mental accounting theory in which the internal reference points are explicitly considered. A questionnaire survey about the shopping trip to the CBD in Matsuyama city was conducted, and then the roles of reference points in travel mode choice contexts were investigated. The result showed that the goodness-of-fit of the developed model was higher than that of the conventional model, indicating that the internal reference points might play the major roles in the choice of travel mode. Also shown was that the respondents seem to utilize various reference points: some tend to adopt the lowest fuel price they have experienced, others employ fare price they feel in perceptions of the travel cost.

Estimation the recreational value of Najvan park of Isfahan using a contingent valuation method

Directory of Open Access Journals (Sweden)

M Sameti

2012-06-01

Full Text Available Determining the real value of natural ecosystems, due to their significant function and ecosystem services and necessity of the best management for make use of them, has a great importance. Recently, natural resource economists have studied ecosystem value of natural resources and its role in human welfare. These studies have made a considerable progress in valuation of environmental as well as ecological services that an ecosystem can offer. Therefore this study tries to determine recreational value of Najvan Park and measure of individual’s willingness to pay (WTP based on contingent valuation method (CVM and dichotomous choices (DC. Logit model was used for measuring of individual WTP. The model parameters were estimated based on the maximum likelihood (ML method. Moreover, the marginal effects of the changes in involved variables in considered model were determined using by factor for calculating of marginal effects. The results showed that individual preservation WTP in Najvan Park is directly related to income and education while it is negatively related tobid, age and the number of family member. The calculation of the expectancy of WTP using logit model led to 8,983 Rials monthly WTP per person.

General methods for analyzing bounded proportion data

OpenAIRE

Hossain, Abu

2017-01-01

This thesis introduces two general classes of models for analyzing proportion response variable when the response variable Y can take values between zero and one, inclusive of zero and/or one. The models are inflated GAMLSS model and generalized Tobit GAMLSS model. The inflated GAMLSS model extends the flexibility of beta inflated models by allowing the distribution on (0,1) of the continuous component of the dependent variable to come from any explicit or transformed (i.e. logit or truncated...

Convertible security design and contract innovation

NARCIS (Netherlands)

Lewis, C.M.; Verwijmeren, P.

2011-01-01

This paper studies convertible security design for a sample of 814 issuers over the years 2000 through 2007. Using a nested logit model, we examine how firms choose fixed income claims and the method of payment. We find that fixed income claims are chosen to reduce corporate income taxes, minimize

Does race matter in landowners' participation in conservation incentive programs?

Science.gov (United States)

Jianbang Gan; Okwuldili O. Onianwa; John Schelhas; Gerald C. Wheelock; Mark R. Dubois

2005-01-01

This study investigated and compared the participation behavior of white and minority small landowners in Alabama in eight conservation incentive programs. Using nonparametric tests and logit modeling, we found both similarities and differences in participation behavior between these two landowner groups. Both white and minority landowners tended not to participate in...

Development and validation of a mortality risk model for pediatric sepsis

Science.gov (United States)

Chen, Mengshi; Lu, Xiulan; Hu, Li; Liu, Pingping; Zhao, Wenjiao; Yan, Haipeng; Tang, Liang; Zhu, Yimin; Xiao, Zhenghui; Chen, Lizhang; Tan, Hongzhuan

2017-01-01

Abstract Pediatric sepsis is a burdensome public health problem. Assessing the mortality risk of pediatric sepsis patients, offering effective treatment guidance, and improving prognosis to reduce mortality rates, are crucial. We extracted data derived from electronic medical records of pediatric sepsis patients that were collected during the first 24 hours after admission to the pediatric intensive care unit (PICU) of the Hunan Children's hospital from January 2012 to June 2014. A total of 788 children were randomly divided into a training (592, 75%) and validation group (196, 25%). The risk factors for mortality among these patients were identified by conducting multivariate logistic regression in the training group. Based on the established logistic regression equation, the logit probabilities for all patients (in both groups) were calculated to verify the model's internal and external validities. According to the training group, 6 variables (brain natriuretic peptide, albumin, total bilirubin, D-dimer, lactate levels, and mechanical ventilation in 24 hours) were included in the final logistic regression model. The areas under the curves of the model were 0.854 (0.826, 0.881) and 0.844 (0.816, 0.873) in the training and validation groups, respectively. The Mortality Risk Model for Pediatric Sepsis we established in this study showed acceptable accuracy to predict the mortality risk in pediatric sepsis patients. PMID:28514310

Flying personal planes: modeling the airport choices of general aviation pilots using stated preference methodology.

Science.gov (United States)

Camasso, M J; Jagannathan, R

2001-01-01

This study employed stated preference (SP) models to determine why general aviation pilots choose to base and operate their aircraft at some airports and not others. Thirteen decision variables identified in pilot focus groups and in the general aviation literature were incorporated into a series of hypothetical choice tasks or scenarios. The scenarios were offered within a fractional factorial design to establish orthogonality and to preclude dominance in any combination of variables. Data from 113 pilots were analyzed for individual differences across pilots using conditional logit regression with and without controls. The results demonstrate that some airport attributes (e.g., full-range hospitality services, paved parallel taxiway, and specific types of runway lighting and landing aids) increase pilot utility. Heavy airport congestion and airport landing fees, on the other hand, decrease pilot utility. The importance of SP methodology as a vehicle for modeling choice behavior and as an input into the planning and prioritization process is discussed. Actual or potential applications include the development of structured decision-making instruments in the behavioral sciences and in human service programs.

DETERMINANTS OF FAST FOOD CONSUMPTION

OpenAIRE

Fanning, Jasper; Marsh, Thomas L.; Stiegert, Kyle W.

2002-01-01

Socioeconomic determinants are investigated for both the likelihood of consuming fastfood and household expenditure on fastfood using the 1994-98 USDA Continuing Survey of Food Intakes by Individuals. The logit model is used to estimate an empirical relationship between probability an individual will consume fastfood and socioeconomic variables. The Tobit model is used to estimate an empirical relationship between expenditure on fastfood and socioeconomic variables. Significant socioeconomic ...

Multinomial logistic regression modelling of obesity and overweight among primary school students in a rural area of Negeri Sembilan

Energy Technology Data Exchange (ETDEWEB)

Ghazali, Amirul Syafiq Mohd; Ali, Zalila; Noor, Norlida Mohd; Baharum, Adam [Pusat Pengajian Sains Matematik, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia amirul@unisel.edu.my, zalila@cs.usm.my, norlida@usm.my, adam@usm.my (Malaysia)

2015-10-22

Multinomial logistic regression is widely used to model the outcomes of a polytomous response variable, a categorical dependent variable with more than two categories. The model assumes that the conditional mean of the dependent categorical variables is the logistic function of an affine combination of predictor variables. Its procedure gives a number of logistic regression models that make specific comparisons of the response categories. When there are q categories of the response variable, the model consists of q-1 logit equations which are fitted simultaneously. The model is validated by variable selection procedures, tests of regression coefficients, a significant test of the overall model, goodness-of-fit measures, and validation of predicted probabilities using odds ratio. This study used the multinomial logistic regression model to investigate obesity and overweight among primary school students in a rural area on the basis of their demographic profiles, lifestyles and on the diet and food intake. The results indicated that obesity and overweight of students are related to gender, religion, sleep duration, time spent on electronic games, breakfast intake in a week, with whom meals are taken, protein intake, and also, the interaction between breakfast intake in a week with sleep duration, and the interaction between gender and protein intake.

Multinomial logistic regression modelling of obesity and overweight among primary school students in a rural area of Negeri Sembilan

International Nuclear Information System (INIS)

Ghazali, Amirul Syafiq Mohd; Ali, Zalila; Noor, Norlida Mohd; Baharum, Adam

2015-01-01

Multinomial logistic regression is widely used to model the outcomes of a polytomous response variable, a categorical dependent variable with more than two categories. The model assumes that the conditional mean of the dependent categorical variables is the logistic function of an affine combination of predictor variables. Its procedure gives a number of logistic regression models that make specific comparisons of the response categories. When there are q categories of the response variable, the model consists of q-1 logit equations which are fitted simultaneously. The model is validated by variable selection procedures, tests of regression coefficients, a significant test of the overall model, goodness-of-fit measures, and validation of predicted probabilities using odds ratio. This study used the multinomial logistic regression model to investigate obesity and overweight among primary school students in a rural area on the basis of their demographic profiles, lifestyles and on the diet and food intake. The results indicated that obesity and overweight of students are related to gender, religion, sleep duration, time spent on electronic games, breakfast intake in a week, with whom meals are taken, protein intake, and also, the interaction between breakfast intake in a week with sleep duration, and the interaction between gender and protein intake

Using New Mode Choice Model Nesting Structures to Address Emerging Policy Questions: A Case Study of the Pittsburgh Central Business District

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Zulqarnain H. Khattak

2017-11-01

Full Text Available As transportation activities affect a region’s environmental quality, knowing why individuals prefer certain modes can help a region make judicious transportation investments. Using a nested logit model, this paper studies the behavior of commuters to downtown Pittsburgh who use auto, bus, light rail, walking, and biking. Although statistical measures influence the selection of a nesting structure, another criterion for model selection is the policy questions such models inform. Hence this paper demonstrates how an alternative model structure allows planners to consider new policy questions. For example, how might a change in parking fee affect greenhouse gas emission (GHGs? The proposed model showed that a 5%, 10% and 15% increase in parking cost reduces GHGs by 7.3%, 9% and 13.2%, respectively, through increasing carpoolers’ mode share. Because the proposed model forecasts mode choices of certain groups of travelers with higher accuracy (compared to an older model that did not consider the model selection criteria presented here, the proposed model strengthens policymakers’ ability to consider environmental impacts of interest to the region (in this case, GHGs. The paper does not suggest that one nesting structure is always preferable; rather the nesting structure must be chosen with the policy considerations in mind.

Determinants of Students Academic Performance in Senior High ...

African Journals Online (AJOL)

A binary logit model is used to investigate the determinants of students' performance in the final high school examination. Questionnaires were administered to a sample of 1,129 final year students (614 boys and 515 girls) in ten senior high schools (SHSs) during the 2008/2009 academic year. Respondents were requested ...

The importance of rating scale design in the measurement of patient-reported outcomes using questionnaires or item banks.

Science.gov (United States)

Khadka, Jyoti; McAlinden, Colm; Gothwal, Vijaya K; Lamoureux, Ecosse L; Pesudovs, Konrad

2012-06-26

To investigate the effect of rating scale designs (question formats and response categories) on item difficulty calibrations and assess the impact that rating scale differences have on overall vision-related activity limitation (VRAL) scores. Sixteen existing patient-reported outcome instruments (PROs) suitable for cataract assessment, with different rating scales, were self-administered by patients on a cataract surgery waiting list. A total of 226 VRAL items from these PROs in their native rating scales were included in an item bank and calibrated using Rasch analysis. Fifteen item/content areas (e.g., reading newspapers) appearing in at least three different PROs were identified. Within each content area, item calibrations were compared and their range calculated. Similarly, five PROs having at least three items in common with the Visual Function (VF-14) were compared in terms of average item measures. A total of 614 patients (mean age ± SD, 74.1 ± 9.4 years) participated. Items with the same content varied in their calibration by as much as two logits; "reading the small print" had the largest range (1.99 logits) followed by "watching TV" (1.60). Compared with the VF-14 (0.00 logits), the rating scale of the Visual Disability Assessment (1.13 logits) produced the most difficult items and the Cataract Symptom Scale (0.24 logits) produced the least difficult items. The VRAL item bank was suboptimally targeted to the ability level of the participants (2.00 logits). Rating scale designs have a significant effect on item calibrations. Therefore, constructing item banks from existing items in their native formats carries risks to face validity and transmission of problems inherent in existing instruments, such as poor targeting.

The role of biomass in US industrial interfuel substitution

International Nuclear Information System (INIS)

Jones, Clifton T.

2014-01-01

The role of biomass in US industrial interfuel substitution in the industrial sector has typically been analyzed using data for the four traditional fuels of coal, oil, electricity and natural gas. However, the use of biomass as an industrial fuel in the US has grown, and now exceeds that of coal. Using data from 1960 to 2011, interfuel substitution in the US industrial sector is modeled with a dynamic linear logit model which includes biomass alongside the other four traditional fuels. Adding biomass to the model reduces somewhat the estimated own-price and cross-price elasticities for the other four fuels, while revealing that biomass and natural gas are substitute fuels. This implies that previous studies excluding biomass may have overestimated the potential for interfuel substitution, giving policy makers an inaccurate impression of the ability of carbon taxes or other environmental regulation to reduce greenhouse gas (GHG) emissions. - Highlights: • Biomass usage by the US industrial sector now exceeds coal usage. • Previous interfuel substitution studies have not included biomass as a fuel. • Linear logit model is used to examine role of biomass in interfuel substitution. • Including biomass in the model lowers estimated price elasticities for traditional fuels. • Biomass is found to be a substitute for natural gas for industrial users

Classification and Casual Modeling of Economic Indicators of Instability in Developing Nations

Science.gov (United States)

1990-03-01

given X, U = random variable normally distributed with a mean of zero and unit variance ( Hanushek and Jackson, 1977:189). The interpretation is the...of this expression yields Equation (3), the log odds or logit equation. P(1 + e - x O) = 1 e -XG = (1 - P)/P X 1 = ln[P/(l - P)] (3) ( Hanushek and...Jackson, 1977:188) Hanushek and Jackson prove that the change in probability of the event’s occurrence due to a change in a single independent variable

Discrete Choice and Rational Inattention

DEFF Research Database (Denmark)

Fosgerau, Mogens; Melo, Emerson; de Palma, André

2017-01-01

This paper establishes a general equivalence between discrete choice and rational inattention models. Matejka and McKay (2015, AER) showed that when information costs are modelled using the Shannon entropy, the result- ing choice probabilities in the rational inattention model take the multinomial...... logit form. We show that when information costs are modelled using a class of generalized entropies, then the choice probabilities in any rational inattention model are observationally equivalent to some additive random utility discrete choice model and vice versa. This equivalence arises from convex...

Random preferences towards bioenergy environmental externalities: a case study of woody biomass based electricity in the Southern United States

Science.gov (United States)

Andres Susaeta; Pankaj Lal; Janaki Alavalapati; Evan Mercer

2011-01-01

This paper contrasts alternate methodological approaches of investigating public preferences, the random parameter logit (RPL) where tastes and preferences of respondents are assumed to be heterogeneous and the conditional logit (CL) approach where tastes and preferences remain fixed for individuals. We conducted a choice experiment to assess preferences for woody...

Model Development for Risk Assessment of Driving on Freeway under Rainy Weather Conditions.

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Xiaonan Cai

Full Text Available Rainy weather conditions could result in significantly negative impacts on driving on freeways. However, due to lack of enough historical data and monitoring facilities, many regions are not able to establish reliable risk assessment models to identify such impacts. Given the situation, this paper provides an alternative solution where the procedure of risk assessment is developed based on drivers' subjective questionnaire and its performance is validated by using actual crash data. First, an ordered logit model was developed, based on questionnaire data collected from Freeway G15 in China, to estimate the relationship between drivers' perceived risk and factors, including vehicle type, rain intensity, traffic volume, and location. Then, weighted driving risk for different conditions was obtained by the model, and further divided into four levels of early warning (specified by colors using a rank order cluster analysis. After that, a risk matrix was established to determine which warning color should be disseminated to drivers, given a specific condition. Finally, to validate the proposed procedure, actual crash data from Freeway G15 were compared with the safety prediction based on the risk matrix. The results show that the risk matrix obtained in the study is able to predict driving risk consistent with actual safety implications, under rainy weather conditions.

A model to predict progression in brain-injured patients.

Science.gov (United States)

Tommasino, N; Forteza, D; Godino, M; Mizraji, R; Alvarez, I

2014-11-01

The study of brain death (BD) epidemiology and the acute brain injury (ABI) progression profile is important to improve public health programs, organ procurement strategies, and intensive care unit (ICU) protocols. The purpose of this study was to analyze the ABI progression profile among patients admitted to ICUs with a Glasgow Coma Score (GCS) ≤8, as well as establishing a prediction model of probability of death and BD. This was a retrospective analysis of prospective data that included all brain-injured patients with GCS ≤8 admitted to a total of four public and private ICUs in Uruguay (N = 1447). The independent predictor factors of death and BD were studied using logistic regression analysis. A hierarchical model consisting of 2 nested logit regression models was then created. With these models, the probabilities of death, BD, and death by cardiorespiratory arrest were analyzed. In the first regression, we observed that as the GCS decreased and age increased, the probability of death rose. Each additional year of age increased the probability of death by 0.014. In the second model, however, BD risk decreased with each year of age. The presence of swelling, mass effect, and/or space-occupying lesion increased BD risk for the same given GCS. In the presence of injuries compatible with intracranial hypertension, age behaved as a protective factor that reduced the probability of BD. Based on the analysis of the local epidemiology, a model to predict the probability of death and BD can be developed. The organ potential donation of a country, region, or hospital can be predicted on the basis of this model, customizing it to each specific situation.

Riding Quality Model for Asphalt Pavement Monitoring Using Phase Array Type L-band Synthetic Aperture Radar (PALSAR

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Kamiya Yoshikazu

2010-11-01

Full Text Available There are difficulties associated with near-real time or frequent pavement monitoring, because it is time consuming and costly. This study aimed to develop a binary logit model for the evaluation of highway riding quality, which could be used to monitor pavement conditions. The model was applied to investigate the influence of backscattering values of Phase Array type L-band Synthetic Aperture Radar (PALSAR. Training data obtained during 3–7 May 2007 was used in the development process, together with actual international roughness index (IRI values collected along a highway in Ayutthaya province, Thailand. The analysis showed that an increase in the backscattering value in the HH or the VV polarization indicated the poor condition of the pavement surface and, of the two, the HH polarization is more suitable for developing riding quality evaluation. The model developed was applied to analyze highway number 3467, to demonstrate its capability. It was found that the assessment accuracy of the prediction of the highway level of service was 97.00%. This is a preliminary study of the proposed technique and more intensive investigation must be carried out using ALOS/PALSAR images in various seasons.

Railway and road discrete choice model for foreign trade freight between Antioquia and the Port of Cartagena

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J. D. Pineda-Jaramillo

2016-09-01

Full Text Available Most Colombian freight is transported on roads with barely acceptable conditions, and although there is a speculation about the need for a railway for freight transportation, there is not a study in Colombia showing the variables that influence the modal choice by the companies that generate freight transportation. This article presents the calculation of demand for a hypothetical railway through a discrete choice model. It begins with a qualitative research through focus group techniques to identify the variables that influence the choice of persons responsible for the transportation of large commercial companies in Antioquia (Colombia. The influential variables in the election were the cost and service frequency, and these variables were used to apply a Stated Preference (SP and Revealed Preference (RP survey, then to calibrate a Multinomial Logit Model (MNL, and to estimate the influence of each of them. We show that the probability of railway choice by the studied companies varies between 67% and 93%, depending on differences in these variables.

Influence of Parking Price on Parking Garage Users’ Behaviour

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Jelena Simićević

2012-09-01

Full Text Available Parking charge is a powerful tool for solving parking and traffic congestion problems. In order to achieve the expected effects without any adverse impact it is necessary to understand well the users’ responses to this policy. This paper, based on a sample of interviewed parking garage users, has developed binary logit model for identification and quantification of characteristics of users and trips, on which the acceptance of parking price is dependent. In addition, multinomial logit model has been made in order to predict what the users will opt for when faced with an increase in parking price. For the first time the parameter “shorten duration” has been introduced which has shown to be the most significant in making behaviour-related decisions. The results show that the users with the purpose work are the most sensitive to an increase in parking charge, what can be deemed positive for policy makers. However, great sensitivity of the users with the purpose shopping should cause their concern. The results of the multinomial model show that they would not discontinue coming into the area after all.

The Sex Difference in Depression across 29 Countries

Science.gov (United States)

Hopcroft, Rosemary L.; Bradley, Dana Burr

2007-01-01

The sex difference in depression is well documented in westernized, developed societies, although there has been little quantitative cross-cultural research on the topic. In this study, we use multilevel logit models to examine sex differences in depression across 29 countries using data from the World Values Survey. We find that in no country are…

Gender, Alcohol Consumption Patterns, and Engagement in Sexually Intimate Behaviors among Adolescents and Young Adults in Nha Trang, Viet Nam

Science.gov (United States)

Kaljee, Linda M.; Green, Mackenzie S.; Zhan, Min; Riel, Rosemary; Lerdboon, Porntip; Lostutter, Ty W.; Tho, Le Huu; Luong, Vo Van; Minh, Truong Tan

2011-01-01

A randomly selected cross-sectional survey was conducted with 880 youth (16 to 24 years) in Nha Trang City to assess relationships between alcohol consumption and sexual behaviors. A timeline followback method was employed. Chi-square, generalized logit modeling and logistic regression analyses were performed. Of the sample, 78.2% male and 56.1%…

Exploring the Effects of Financial Aid on the Gap in Student Dropout Risks by Income Level

Science.gov (United States)

Chen, Rong; DesJardins, Stephen L.

2008-01-01

Using national survey data and discrete-time logit modeling, this research seeks to understand whether student aid mediates the relationship between parental income and student dropout behavior. Our analysis confirms that there is a gap in dropout rates for low-income students compared with their upper income peers, and suggests that some types of…

Life Satisfaction among Turkish and Moroccan Immigrants in the Netherlands: The Role of Absolute and Relative Income

Science.gov (United States)

Gokdemir, Ozge; Dumludag, Devrim

2012-01-01

In this paper we investigate the role of several socio-economic and non-economic factors such as absolute and relative income, education and religion to explain the differences of happiness levels of Turkish and Moroccan Immigrants in the Netherlands by using ordered logit model. We focus on members of the Moroccan and Turkish communities, as…

The arcsine is asinine: the analysis of proportions in ecology.

Science.gov (United States)

Warton, David I; Hui, Francis K C

2011-01-01

The arcsine square root transformation has long been standard procedure when analyzing proportional data in ecology, with applications in data sets containing binomial and non-binomial response variables. Here, we argue that the arcsine transform should not be used in either circumstance. For binomial data, logistic regression has greater interpretability and higher power than analyses of transformed data. However, it is important to check the data for additional unexplained variation, i.e., overdispersion, and to account for it via the inclusion of random effects in the model if found. For non-binomial data, the arcsine transform is undesirable on the grounds of interpretability, and because it can produce nonsensical predictions. The logit transformation is proposed as an alternative approach to address these issues. Examples are presented in both cases to illustrate these advantages, comparing various methods of analyzing proportions including untransformed, arcsine- and logit-transformed linear models and logistic regression (with or without random effects). Simulations demonstrate that logistic regression usually provides a gain in power over other methods.

Effect of Policy Interventions on Food Security in Tigray, Northern Ethiopia

Directory of Open Access Journals (Sweden)

Anne van der Veen

2011-03-01

Full Text Available Following the design of a conservation-based agricultural development strategy and food security strategy, the Tigray government has implemented different pro-poor development programs over the past years to address the problems of food security. This study attempts to investigate the effectiveness of government policy interventions at different scales addressed to improve food security. Food security both at the regional and district level was investigated by deriving food balance sheets for the period 2000-2008. An empirical analysis based on a logit model was also employed to analyze household level food security status. The results of the logit model reveal that government policy interventions such as water harvesting schemes, employment generation schemes, and promotion of technology adoption significantly contribute to a higher likelihood of household food security status. The findings of the food balance sheet also indicate that the region has made some impressive development gains in improving regional food self-sufficiency, indicating the importance of government interventions in improving food security both at the household and regional level.

Does Merger Simulation Work? A "Natural Experiment" in the Swedish Analgesics Market Market

OpenAIRE

Björnerstedt, Jonas; Verboven, Frank

2012-01-01

We exploit a natural experiment associated with a large merger in the Swedish market for analgesics (painkillers). We confront the predictions from a merger simulation study, as conducted during the investigation, with the actual merger effects over a two-year comparison window. The merger simulation model is based on a constant expenditures specification for the nested logit model (as an alternative to the typical unit demand specification). The model predicts a large price increase of 34% b...

Bayesian inference in an item response theory model with a generalized student t link function

Science.gov (United States)

Azevedo, Caio L. N.; Migon, Helio S.

2012-10-01

In this paper we introduce a new item response theory (IRT) model with a generalized Student t-link function with unknown degrees of freedom (df), named generalized t-link (GtL) IRT model. In this model we consider only the difficulty parameter in the item response function. GtL is an alternative to the two parameter logit and probit models, since the degrees of freedom (df) play a similar role to the discrimination parameter. However, the behavior of the curves of the GtL is different from those of the two parameter models and the usual Student t link, since in GtL the curve obtained from different df's can cross the probit curves in more than one latent trait level. The GtL model has similar proprieties to the generalized linear mixed models, such as the existence of sufficient statistics and easy parameter interpretation. Also, many techniques of parameter estimation, model fit assessment and residual analysis developed for that models can be used for the GtL model. We develop fully Bayesian estimation and model fit assessment tools through a Metropolis-Hastings step within Gibbs sampling algorithm. We consider a prior sensitivity choice concerning the degrees of freedom. The simulation study indicates that the algorithm recovers all parameters properly. In addition, some Bayesian model fit assessment tools are considered. Finally, a real data set is analyzed using our approach and other usual models. The results indicate that our model fits the data better than the two parameter models.

EFFECTS OF ECONOMIC BEHAVIOUR AND PEIPLE MIGRANTION ON THE EPIDEMIOLOGY OF MALARIA : A MODEL BASED STUDY

Directory of Open Access Journals (Sweden)

Sajal Bhattacharya

2006-11-01

Full Text Available The objective of the paper is to study the socio economic behaviour of migrant labourers in the context of the control of the diseases like malaria. The paper, therefore, makes a model and survey based study in the city of Kolkata, India to drive home the point that low income of people particularly of the migrant workers can be a major hurdle in the malaria control programme. The paper first looks at the economic behaviour pattern theoretically from neo-classical optimization exercise and the tries to test the theoetical result empirically from primary survey. The theoritical model gives the result that low income people is likely to take less rest and discontinue medical tratment. Since migrant workers of less developed counties are usually low-income people, pur model suggests that migrant workers will have incomplete treatment and their migration even before complete recovery may contribute to spread of the disease. We hage empirically tested the model econometrically by a logit model, and derived the result that migrat workers do take less rest and discontinue treatment becouse of economic compulsion. Thus the data support the result of the theoretical model and refeals a behafiour pattern, conducive to spread of malaria infection. The paper drives some policy prescriptions on the basis of these studies like infurance support, health survillance of migrant population as a part of integrated malaria control programme.

Elasticity of Demand for Tuition Fees at an Institution of Higher Education

Science.gov (United States)

Langelett, George; Chang, Kuo-Liang; Ola' Akinfenwa, Samson; Jorgensen, Nicholas; Bhattarai, Kopila

2015-01-01

Using a conjoint survey of 161 students at South Dakota State University (SDSU), we mapped a probability-of-enrolment curve for SDSU students, consistent with demand theory. A quasi-demand curve was created from the conditional-logit model. This study shows that along with the price of tuition fees, distance from home, availability of majors, and…

Determinants of Use of Indigenous Fish Processing Practices in ...

African Journals Online (AJOL)

Descriptive statistics was used to analyze the socio- economic features of the fish processors while the logit model was used to capture the socio-economic factors ... education (β=1.90), household size (β=2.48), FAI (β=2.80), consumers preference (β=3.37), processing tradition (β=3.74), VFP (β=0.02) and cosmopoliteness ...

Does Education Affect Happiness? Evidence for Spain

Science.gov (United States)

Cunado, Juncal; de Gracia, Fernando Perez

2012-01-01

In this paper we study the impact of education on happiness in Spain using individual-level data from the European Social Survey, by means of estimating Ordinal Logit Models. We find both direct and indirect effects of education on happiness. First, we find an indirect effect of education on happiness through income and labour status. That is, we…

An analysis of factors affecting participation behavior of limited resource farmers in agricultural cost-share programs in Alabama

Science.gov (United States)

Okwudili Onianwa; Gerald Wheelock; Buddhi Gyawali; Jianbang Gan; Mark Dubois; John Schelhas

2004-01-01

This study examines factors that affect the participation behavior of limited resource farmers in agricultural cost-share programs in Alabama. The data were generated from a survey administered to a sample of limited resource farm operators. A binary logit model was employed to analyze the data. Results indicate that college education, age, gross sales, ratio of owned...

Economic Analysis of Job-Related Attributes in Undergraduate Students' Initial Job Selection

Science.gov (United States)

Jin, Yanhong H.; Mjelde, James W.; Litzenberg, Kerry K.

2014-01-01

Economic tradeoffs students place on location, salary, distances to natural resource amenities, size of the city where the job is located, and commuting times for their first college graduate job are estimated using a mixed logit model for a sample of Texas A&M University students. The Midwest is the least preferred area having a mean salary…

Them That's Got: How Tie Formation in Partnership Networks Gives High Schools Differential Access to Social Capital

Science.gov (United States)

Bridwell-Mitchell, E. N.

2017-01-01

School partnerships are important sources of school social capital. Schools may have unequal access to social capital due to the pattern of relationships in the school-partner network. Using data on school resource needs, sociometric measures, and a set of multilevel logit models, the results of a study of 211 New York City public high schools and…

Analysing the Severity and Frequency of Traffic Crashes in Riyadh City Using Statistical Models

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Saleh Altwaijri

2012-12-01

Full Text Available Traffic crashes in Riyadh city cause losses in the form of deaths, injuries and property damages, in addition to the pain and social tragedy affecting families of the victims. In 2005, there were a total of 47,341 injury traffic crashes occurred in Riyadh city (19% of the total KSA crashes and 9% of those crashes were severe. Road safety in Riyadh city may have been adversely affected by: high car ownership, migration of people to Riyadh city, high daily trips reached about 6 million, high rate of income, low-cost of petrol, drivers from different nationalities, young drivers and tremendous growth in population which creates a high level of mobility and transport activities in the city. The primary objective of this paper is therefore to explore factors affecting the severity and frequency of road crashes in Riyadh city using appropriate statistical models aiming to establish effective safety policies ready to be implemented to reduce the severity and frequency of road crashes in Riyadh city. Crash data for Riyadh city were collected from the Higher Commission for the Development of Riyadh (HCDR for a period of five years from 1425H to 1429H (roughly corresponding to 2004-2008. Crash data were classified into three categories: fatal, serious-injury and slight-injury. Two nominal response models have been developed: a standard multinomial logit model (MNL and a mixed logit model to injury-related crash data. Due to a severe underreporting problem on the slight injury crashes binary and mixed binary logistic regression models were also estimated for two categories of severity: fatal and serious crashes. For frequency, two count models such as Negative Binomial (NB models were employed and the unit of analysis was 168 HAIs (wards in Riyadh city. Ward-level crash data are disaggregated by severity of the crash (such as fatal and serious injury crashes. The results from both multinomial and binary response models are found to be fairly consistent but

Abusive alcohol consumption among adolescents: a predictive model for maximizing early detection and responses.

Science.gov (United States)

de Freitas Ferreira, M; de Moraes, C L; Braga, J U; Reichenheim, M E; da Veiga, G V

2018-03-17

To present a predictive model of alcohol abuse among adolescents based on prevalence projections in various population subgroups. Cross-sectional study. The sample consisted of 785 adolescents enrolled in the second year of high school in Rio de Janeiro, Brazil. Alcohol consumption was assessed using the Alcohol Use Disorder Identification Test. Socio-economic, demographic, family, individuals, and school-related variables were examined as potential predictors. The logit model was used to estimate the prevalence projections. Model fitting was examined in relation to the observed data set, and in a subset, that was generated from 200 subsamples of individuals via a bootstrap process using general fit estimators, discrimination, and calibration measures. About 25.5% of the adolescents were classified as positive for alcohol abuse. Being male, being 17-19 years old, not living with mothers, presenting symptoms suggestive of binge eating, having used a strategy of weight reduction in the last 3 months, and, especially, being a victim of family violence were important predictors of abusive consumption of alcohol. While the model's prevalence projection in the absence of these features was 8%, it reaches 68% in the presence of all predictors. Knowledge of predictive characteristics of alcohol abuse is essential for screening, early detection of positive cases, and establishing interventions to reduce consumption among adolescents. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Impacts of geographical locations and sociocultural traits on the Vietnamese entrepreneurship.

Science.gov (United States)

Vuong, Quan Hoang

2016-01-01

This paper presents new results obtained from investigating the data from a 2015 Vietnamese entrepreneurs' survey, containing 3071 observations. Evidence from the estimations using multinomial logits was found to support relationships between several sociocultural factors and entrepreneurship-related performance or traits. Specifically, those relationships include: (a) Active participation in entrepreneurs' social networks and reported value of creativity; (b) CSR-willingness and reported entrepreneurs' perseverance; (c) Transforming of sociocultural values and entrepreneurs' decisiveness; and, (d) Lessons learned from others' failures and perceived chance of success. Using geographical locations as the control variate, evaluations of the baseline-category logits models indicate their varying effects on the outcomes when combined with the sociocultural factors that are found to be statistically significant. Empirical probabilities that give further detail about behavioral patterns are provided; and toward the end, the paper offers some conclusions with some striking insights and useful explanations on the Vietnamese entrepreneurship processes.

A multinomial-logit ordered-probit model for jointly analyzing crash avoidance maneuvers and crash severity

DEFF Research Database (Denmark)

Kaplan, Sigal; Prato, Carlo Giacomo

' propensity to engage in various corrective maneuvers in the case of the critical event of vehicle travelling. Five lateral and speed control maneuvers are considered: “braking”, “steering”, “braking & steering”, and “other maneuvers”, in addition to a “no action” option. The analyzed data are retrieved from...... the United States National Automotive Sampling System General Estimates System (GES) crash database for the years 2005-2009. Results show (i) the correlation between crash avoidance maneuvers and crash severity, and (ii) the link between drivers' attributes, risky driving behavior, road characteristics...

Generalized Partial Least Squares Approach for Nominal Multinomial Logit Regression Models with a Functional Covariate

Science.gov (United States)

Albaqshi, Amani Mohammed H.

2017-01-01

Functional Data Analysis (FDA) has attracted substantial attention for the last two decades. Within FDA, classifying curves into two or more categories is consistently of interest to scientists, but multi-class prediction within FDA is challenged in that most classification tools have been limited to binary response applications. The functional…

Associating crash avoidance maneuvers with driver attributes and accident characteristics: a mixed logit model approach

DEFF Research Database (Denmark)

Kaplan, Sigal; Prato, Carlo Giacomo

2012-01-01

from the key role of proactive and state-aware road users within the concept of sustainable safety systems, as well as from the key role of effective corrective maneuvers in the success of automated in-vehicle warning and driver assistance systems. Methods: The analysis is conducted by means of a mixed...... about the risks of driving under fatigue and distraction being comparable to the risks of driving under the influence of alcohol and drugs. Moreover, the results suggest the need to educate drivers about hazard perception, designing a forgiving infrastructure within a sustainable safety systems......Objective: The current study focuses on the propensity of drivers to engage in crash avoidance maneuvers in relation to driver attributes, critical events, crash characteristics, vehicles involved, road characteristics, and environmental conditions. The importance of avoidance maneuvers derives...

Ordering the Preference Hierarchies for Internal Finance, Bank Loans, Bond and Share Issues

OpenAIRE

Leo de Haan; Jeroen Hinloopen

2002-01-01

We estimate the incremental financing decision for a sample of some 150Dutch companies for the years 1984 through 1997, thereby distinguishinginternal finance and three types of external finance: bank borrowing, bondissues and share issues. First, we estimate a multinomial logit model whichconfirms several predictions of both the static trade-off theory and thepecking-order theory as to the determinants of financing choices. Next, weuse ordered probit models to determine which financing hiera...

Disability and multi-state labour force choices with state dependence

OpenAIRE

Oguzoglu, Umut

2010-01-01

I use a dynamic mixed multinomial logit model with unobserved heterogeneity to study the impact of work limiting disabilities on disaggregated labour choices. The first seven waves of the Household Income and Labour Dynamics in Australia survey are used to investigate this relationship. Findings point out to strong state dependence in employment choices. Further, the impact of disability on employment outcomes is highly significant. Model simulations suggest that high cross and own state depe...

Spillover Effects of TV Advertising: The Case of Carbonated Soft Drinks

OpenAIRE

Li, Xun; Lopez, Rigoberto A.

2012-01-01

This paper examines the spillover effects of television brand advertising on consumer demand for carbonated soft drinks using a nested logit model and household purchase and advertising data from nine U.S. cities over a three year period. Spillover effects are modeled using the conventional linear advertising production function with brand and company advertising, which assumes perfect substitution and constant returns to scale, and the results are compared to those attained via a constant el...

Modeling Left-Turn Driving Behavior at Signalized Intersections with Mixed Traffic Conditions

Directory of Open Access Journals (Sweden)

Hong Li

2016-01-01

Full Text Available In many developing countries, mixed traffic is the most common type of urban transportation; traffic of this type faces many major problems in traffic engineering, such as conflicts, inefficiency, and security issues. This paper focuses on the traffic engineering concerns on the driving behavior of left-turning vehicles caused by different degrees of pedestrian violations. The traffic characteristics of left-turning vehicles and pedestrians in the affected region at a signalized intersection were analyzed and a cellular-automata-based “following-conflict” driving behavior model that mainly addresses four basic behavior modes was proposed to study the conflict and behavior mechanisms of left-turning vehicles by mathematic methodologies. Four basic driving behavior modes were reproduced in computer simulations, and a logit model of the behavior mode choice was also developed to analyze the relative share of each behavior mode. Finally, the microscopic characteristics of driving behaviors and the macroscopic parameters of traffic flow in the affected region were all determined. These data are important reference for geometry and capacity design for signalized intersections. The simulation results show that the proposed models are valid and can be used to represent the behavior of left-turning vehicles in the case of conflicts with illegally crossing pedestrians. These results will have potential applications on improving traffic safety and traffic capacity at signalized intersections with mixed traffic conditions.

Identifying potential misfit items in cognitive process of learning engineering mathematics based on Rasch model

International Nuclear Information System (INIS)

Ataei, Sh; Mahmud, Z; Khalid, M N

2014-01-01

The students learning outcomes clarify what students should know and be able to demonstrate after completing their course. So, one of the issues on the process of teaching and learning is how to assess students' learning. This paper describes an application of the dichotomous Rasch measurement model in measuring the cognitive process of engineering students' learning of mathematics. This study provides insights into the perspective of 54 engineering students' cognitive ability in learning Calculus III based on Bloom's Taxonomy on 31 items. The results denote that some of the examination questions are either too difficult or too easy for the majority of the students. This analysis yields FIT statistics which are able to identify if there is data departure from the Rasch theoretical model. The study has identified some potential misfit items based on the measurement of ZSTD where the removal misfit item was accomplished based on the MNSQ outfit of above 1.3 or less than 0.7 logit. Therefore, it is recommended that these items be reviewed or revised to better match the range of students' ability in the respective course.

Sequence analysis in multilevel models. A study on different sources of patient cues in medical consultations.

Science.gov (United States)

Del Piccolo, Lidia; Mazzi, Maria Angela; Dunn, Graham; Sandri, Marco; Zimmermann, Christa

2007-12-01

The aims of the study were to explore the importance of macro (patient, physician, consultation) and micro (doctor-patient speech sequences) variables in promoting patient cues (unsolicited new information or expressions of feelings), and to describe the methodological implications related to the study of speech sequences. Patient characteristics, a consultation index of partnership and doctor-patient speech sequences were recorded for 246 primary care consultations in six primary care surgeries in Verona, Italy. Homogeneity and stationarity conditions of speech sequences allowed the creation of a hierarchy of multilevel logit models including micro and macro level variables, with the presence/absence of cues as the dependent variable. We found that emotional distress of the patient increased cues and that cues appeared among other patient expressions and were preceded by physicians' facilitations and handling of emotion. Partnership, in terms of open-ended inquiry, active listening skills and handling of emotion by the physician and active participation by the patient throughout the consultation, reduced cue frequency.

Population levels of wellbeing and the association with social capital.

Science.gov (United States)

Taylor, A W; Kelly, G; Dal Grande, E; Kelly, D; Marin, T; Hey, N; Burke, K J; Licinio, J

2017-07-03

This research investigates wellbeing at the population level across demographic, social and health indicators and assesses the association between wellbeing and social capital. Data from a South Australian monthly chronic disease/risk factor surveillance system of randomly selected adults (mean age 48.7 years; range 16-99) from 2014/5 (n = 5551) were used. Univariable analyses compared wellbeing/social capital indicators, socio-demographic, risk factors and chronic conditions. Multi-nominal logistic regression modelling, adjusting for multiple covariates was used to simultaneously estimate odds ratios for good wellbeing (reference category) versus neither good nor poor, and good wellbeing versus poor wellbeing. 48.6% were male, mean age 48.7 (sd 18.3), 54.3% scored well on all four of the wellbeing indicators, and positive social capital indicators ranged from 93.1% for safety to 50.8% for control over decisions. The higher level of social capital corresponded with the good wellbeing category. Modeling showed higher odds ratios for all social capital variables for the lowest level of wellbeing. These higher odds ratios remained after adjusting for confounders. The relationship between wellbeing, resilience and social capital highlights areas for increased policy focus.

Keep Calm and Learn Multilevel Logistic Modeling: A Simplified Three-Step Procedure Using Stata, R, Mplus, and SPSS

OpenAIRE

Nicolas Sommet; Davide Morselli

2017-01-01

This paper aims to introduce multilevel logistic regression analysis in a simple and practical way. First, we introduce the basic principles of logistic regression analysis (conditional probability, logit transformation, odds ratio). Second, we discuss the two fundamental implications of running this kind of analysis with a nested data structure: In multilevel logistic regression, the odds that the outcome variable equals one (rather than zero) may vary from one cluster to another (i.e. the i...

Effects of economic crisis on the distribution of earnings from Romania

OpenAIRE

Amalia CRISTESCU; Dorel AILENEI

2015-01-01

The wage gap issue as well as that of income inequality has been a key topic in economics. The supervision of these gaps is essential in terms of labour stimulation and orientation in order to support social progress and to maintain the economic and social cohesion. Starting from a positive approach, but considering the risks of a limiting analysis, in this article, the authors analyzed the determinants of earnings inequality in Romania through an ordered-logit model. The model...

Linking apple farmers to markets: Determinants and impacts of marketing contracts in China

OpenAIRE

Ma, Wanglin; Abdulai, Awudu

2015-01-01

This study investigates the determinants of marketing contract choices and the related impact on farm net returns of apple farmers in China. We employ a two-stage selection correction approach (BFG) for the multinomial logit model. On the basis of the BFG estimation, we also use an endogenous switching regression model and a propensity score matching technique to estimate the causal effects of marketing contract choices on net returns. The empirical results reveal that written contracts incre...

Estimating the Open Market Desk's Daily Reaction Function.

OpenAIRE

Feinman, Joshua N

1993-01-01

This paper presents the results of an empirical investigation into the proximate determinants of the Federal Reserve's daily open market operations. Using information available each morning at the Fed conference call, the author models the Open Market Desk's choice of both the quantity and the type of operation, using a friction model for the former and a multinomial logit framework for the latter. Different types of operations are shown to send different signals to the market about the under...

The Role of Internal Reference Points in the Category Purchase Decision.

OpenAIRE

Bell, David R; Bucklin, Randolph E

1999-01-01

The authors study the role that reference effects play in the category purchase decision for consumer nondurable products. Category purchase behavior is represented by a nested logit model that is estimated on purchase records of shoppers in two Universal Product Code (UPC) scanner panels. A series of hypotheses are developed, modeled, and tested regarding the effects that internal reference points for product category attractiveness are likely to have on the decision to buy in a product cate...

CONSUMER DEMAND FOR AND ATTITUDES TOWARD ALTERNATIVE BEEF LABELING STRATEGIES IN FRANCE, GERMANY, AND THE UK

OpenAIRE

Roosen, Jutta; Lusk, Jayson L.; Fox, John A.

2001-01-01

A wide array of food safety scares and breakdowns have led to loss of consumer confidence in the quality and safety of beef products. To counteract such concerns, firms and regulators have the ability to utilize brands or labels to signal quality. Utilizing a mail survey in France, Germany, and the United Kingdom, we analyzed consumer preferences for alternative beef labeling strategies. Using an ordered probit model and a double bounded logit model, we estimate consumer preferences for alter...

Proposição de um modelo baseado em Customer Lifetime Value para a análise de melhorias no sistema produtivo Proposition of a Customer Lifetime Value model to evaluate production system improvements

Directory of Open Access Journals (Sweden)

Luís Felipe Riehs Camargo

2011-01-01

Full Text Available Este artigo propõe um modelo para analisar melhorias no sistema produtivo à luz do valor do cliente para a empresa. Para isso, apresenta um modelo que agrega variáveis advindas do processo produtivo, do mercado consumidor e de métricas do marketing. Os três pilares de sustentação do modelo são os clientes, com suas necessidades e percepções em relação aos produtos e serviços; as características atribuídas pela produção; e as regras para análise do impacto da adoção de diferentes melhorias no sistema produtivo sobre o valor vitalício dos clientes atuais (CLV. Além disso, um modelo de escolha discreta (logit é proposto como o integrador entre a produção e o marketing. O método de pesquisa utilizado foi composto de quatro etapas: levantamento de referencial; construção do modelo conceitual; aplicação em um caso; análise e discussão. Como resultados, observa-se que, havendo disponibilidade de informações e tempo para sua condução, o modelo contribui para a identificação de melhorias que contemplem simultaneamente a visão de produção e a de sustentabilidade financeira.This paper aims to propose a model to investigate the effect of improvements on the productive system on the organization considering customer value. The model proposed combine variables representing the productive process, market, and marketing metrics. It consists of three fundamental elements: consumers and their needs and perceptions of products and services; characteristics of the productive system; and rules to analyze the impact of adoption of different improvements on the productive system. Customer lifetime value (CLV was measured and a discrete choice model (logit is proposed as an integrator between production and marketing perspectives. The research methodology consisted of four steps: referential research, conceptual modeling, application in a particular case, and results analysis. As a result, it is observed that upon availability

A dynamic analysis of interfuel substitution for Swedish heating plants

International Nuclear Information System (INIS)

Braennlund, R.; Lundgren, T.

2000-01-01

This paper estimates a dynamic model of interfuel substitution for Swedish heating plants. We use the cost share linear logit model developed by Considine and Mount. All estimated own-price elasticities are negative and all cross-price elasticities are positive. The estimated dynamic adjustment rate parameter is small, however increasing with the size of the plant and time, indicating fast adjustments in the fuel mix when changing relative fuel prices. The estimated model is used to illustrate the effects of two different policy changes

Keep Calm and Learn Multilevel Logistic Modeling: A Simplified Three-Step Procedure Using Stata, R, Mplus, and SPSS

Directory of Open Access Journals (Sweden)

Nicolas Sommet

2017-09-01

Full Text Available This paper aims to introduce multilevel logistic regression analysis in a simple and practical way. First, we introduce the basic principles of logistic regression analysis (conditional probability, logit transformation, odds ratio. Second, we discuss the two fundamental implications of running this kind of analysis with a nested data structure: In multilevel logistic regression, the odds that the outcome variable equals one (rather than zero may vary from one cluster to another (i.e. the intercept may vary and the effect of a lower-level variable may also vary from one cluster to another (i.e. the slope may vary. Third and finally, we provide a simplified three-step “turnkey” procedure for multilevel logistic regression modeling: -Preliminary phase: Cluster- or grand-mean centering variables -Step #1: Running an empty model and calculating the intraclass correlation coefficient (ICC -Step #2: Running a constrained and an augmented intermediate model and performing a likelihood ratio test to determine whether considering the cluster-based variation of the effect of the lower-level variable improves the model fit -Step #3 Running a final model and interpreting the odds ratio and confidence intervals to determine whether data support your hypothesis Command syntax for Stata, R, Mplus, and SPSS are included. These steps will be applied to a study on Justin Bieber, because everybody likes Justin Bieber.1

Why Did People Move During the Great Recession? The Role of Economics in Migration Decisions

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Brian L. Levy

2017-04-01

Full Text Available Labor migration offers an important mechanism to reallocate workers when there are regional differences in employment conditions. Whereas conventional wisdom suggests migration rates should increase during recessions as workers move out of areas that are hit hardest, initial evidence suggested that overall migration rates declined during the Great Recession, despite large regional differences in unemployment and growth rates. In this paper we use data from the American Community Survey to analyze internal migration trends before and during the economic downturn. First, we find only a modest decline in the odds of adults leaving distressed labor market areas during the Great Recession, which may result in part from challenges related to the housing price crash. Second, we estimate conditional logit models of destination choice for individuals who migrate across labor market areas; we find a substantial effect of economic factors such as labor demand, unemployment, and housing values. We also estimate latent class conditional logit models that test whether there is heterogeneity in preferences for destination characteristics among migrants. Over all, the latent class models suggest that roughly equal percentages of migrants were motivated by economic factors before and during the Great Recession. We conclude that fears of dramatic declines in labor migration seem to be unsubstantiated.

Why Did People Move During the Great Recession?: The Role of Economics in Migration Decisions.

Science.gov (United States)

Levy, Brian L; Mouw, Ted; Daniel Perez, Anthony

2017-04-01

Labor migration offers an important mechanism to reallocate workers when there are regional differences in employment conditions. Whereas conventional wisdom suggests migration rates should increase during recessions as workers move out of areas that are hit hardest, initial evidence suggested that overall migration rates declined during the Great Recession, despite large regional differences in unemployment and growth rates. In this paper, we use data from the American Community Survey to analyze internal migration trends before and during the economic downturn. First, we find only a modest decline in the odds of adults leaving distressed labor market areas during the recession, which may result in part from challenges related to the housing price crash. Second, we estimate conditional logit models of destination choice for individuals who migrate across labor market areas and find a substantial effect of economic factors such as labor demand, unemployment, and housing values. We also estimate latent class conditional logit models that test whether there is heterogeneity in preferences for destination characteristics among migrants. Over all, the latent class models suggest that roughly equal percentages of migrants were motivated by economic factors before and during the recession. We conclude that fears of dramatic declines in labor migration seem to be unsubstantiated.

Tras los rastros de la movilización social y la confianza pública: apuntes sobre capital social y desarrollo en el departamento del Cauca After Traces of Social Mobilization and Public Trust: Notes on Social Capital and Development in the Department of Cauca

Directory of Open Access Journals (Sweden)

Raúl Cortés Landázur

2010-12-01

Full Text Available El presente artículo busca en la actividad movilizatoria post reformas institucionales de la década del 90, rastros de capital social en el Departamento del Cauca. Se establece una relación entre dicha actividad movilizatoria y la estructura de las organizaciones de la sociedad civil del Cauca, a través de un modelo econométrico (logit bivariado, que pretende mostrar los principales determinantes del capital social interno y externo, impulsores del desarrollo regional.The present article looks within the mobilizing activity of post institutional reforms of the decade of the 90’s, for the characteristics of social capital in the Department of Cauca. It looks to establish a relationship between this mobilizing activity, and the structures of Cauca’s civil society organizations, through an econometric model (logit bivariate, that seeks to show the main determinants of internal and external social capital, which are motors of regional development.

A Spatial-Filtering Zero-Inflated Approach to the Estimation of the Gravity Model of Trade

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Rodolfo Metulini

2018-02-01

Full Text Available Nonlinear estimation of the gravity model with Poisson-type regression methods has become popular for modelling international trade flows, because it permits a better accounting for zero flows and extreme values in the distribution tail. Nevertheless, as trade flows are not independent from each other due to spatial and network autocorrelation, these methods may lead to biased parameter estimates. To overcome this problem, eigenvector spatial filtering (ESF variants of the Poisson/negative binomial specifications have been proposed in the literature on gravity modelling of trade. However, no specific treatment has been developed for cases in which many zero flows are present. This paper contributes to the literature in two ways. First, by employing a stepwise selection criterion for spatial filters that is based on robust (sandwich p-values and does not require likelihood-based indicators. In this respect, we develop an ad hoc backward stepwise function in R. Second, using this function, we select a reduced set of spatial filters that properly accounts for importer-side and exporter-side specific spatial effects, as well as network effects, both at the count and the logit processes of zero-inflated methods. Applying this estimation strategy to a cross-section of bilateral trade flows between a set of 64 countries for the year 2000, we find that our specification outperforms the benchmark models in terms of model fitting, both considering the AIC and in predicting zero (and small flows.

Airport choice model in multiple airport regions

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Claudia Muñoz

2017-02-01

Full Text Available Purpose: This study aims to analyze travel choices made by air transportation users in multi airport regions because it is a crucial component when planning passenger redistribution policies. The purpose of this study is to find a utility function which makes it possible to know the variables that influence users’ choice of the airports on routes to the main cities in the Colombian territory. Design/methodology/approach: This research generates a Multinomial Logit Model (MNL, which is based on the theory of maximizing utility, and it is based on the data obtained on revealed and stated preference surveys applied to users who reside in the metropolitan area of Aburrá Valley (Colombia. This zone is the only one in the Colombian territory which has two neighboring airports for domestic flights. The airports included in the modeling process were Enrique Olaya Herrera (EOH Airport and José María Córdova (JMC Airport. Several structure models were tested, and the MNL proved to be the most significant revealing the common variables that affect passenger airport choice include the airfare, the price to travel the airport, and the time to get to the airport. Findings and Originality/value: The airport choice model which was calibrated corresponds to a valid powerful tool used to calculate the probability of each analyzed airport of being chosen for domestic flights in the Colombian territory. This is done bearing in mind specific characteristic of each of the attributes contained in the utility function. In addition, these probabilities will be used to calculate future market shares of the two airports considered in this study, and this will be done generating a support tool for airport and airline marketing policies.

Calculating the Probability of Returning a Loan with Binary Probability Models

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Julian Vasilev

2014-12-01

Full Text Available The purpose of this article is to give a new approach in calculating the probability of returning a loan. A lot of factors affect the value of the probability. In this article by using statistical and econometric models some influencing factors are proved. The main approach is concerned with applying probit and logit models in loan management institutions. A new aspect of the credit risk analysis is given. Calculating the probability of returning a loan is a difficult task. We assume that specific data fields concerning the contract (month of signing, year of signing, given sum and data fields concerning the borrower of the loan (month of birth, year of birth (age, gender, region, where he/she lives may be independent variables in a binary logistics model with a dependent variable “the probability of returning a loan”. It is proved that the month of signing a contract, the year of signing a contract, the gender and the age of the loan owner do not affect the probability of returning a loan. It is proved that the probability of returning a loan depends on the sum of contract, the remoteness of the loan owner and the month of birth. The probability of returning a loan increases with the increase of the given sum, decreases with the proximity of the customer, increases for people born in the beginning of the year and decreases for people born at the end of the year.

Heterogeneity in preferences and behavior in threshold models

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Philip R Neary

2017-12-01

Full Text Available A coordination game is repeatedly played on a graph by players (vertices who have heterogeneous cardinal preferences and whose strategy choice is governed by the individualistic asynchronous logit dynamic. The idea of potential driven autonomy of sets of players is used to derive results on the possibility of heterogeneous preferences leading to heterogeneous behavior. In particular, a class of graphs is identified such that for large enough graphs in this class, diversity in ordinal preferences will nearly always lead to heterogeneity in behavior, regardless of the cardinal strength of the preferences. These results have implications for network design problems, such as when a social planner wishes to induce homogeneous/heterogeneous behavior in a population.

Performance of various mathematical methods for computer-aided processing of radioimmunoassay results

International Nuclear Information System (INIS)

Vogt, W.; Sandel, P.; Langfelder, Ch.; Knedel, M.

1978-01-01

The performance of 6 algorithms were compared for computer aided determination of radioimmunological end results. These were weighted and unweighted linear logit log regression; quadratic logit log regression, smoothing spline interpolation with a large and small smoothing factor, respectively, and polygonal interpolation and the manual curve fitting on the basis of three radioimmunoassays with different reference curve characteristics (digoxin, estriol, human chorionic somatomammotrophin (HCS)). Great store was set by the accuracy of the approximation at the intermediate points on the curve, i.e. those points that lie midway between two standard concentrations. These concentrations were obtained by weighing and inserted as unknown samples. In the case of digoxin and estriol the polygonal interpolation provided the best results, while the weighted logit log regression proved superior in the case of HCS. (Auth.)

An R package for analyzing and modeling ranking data.

Science.gov (United States)

Lee, Paul H; Yu, Philip L H

2013-05-14

In medical informatics, psychology, market research and many other fields, researchers often need to analyze and model ranking data. However, there is no statistical software that provides tools for the comprehensive analysis of ranking data. Here, we present pmr, an R package for analyzing and modeling ranking data with a bundle of tools. The pmr package enables descriptive statistics (mean rank, pairwise frequencies, and marginal matrix), Analytic Hierarchy Process models (with Saaty's and Koczkodaj's inconsistencies), probability models (Luce model, distance-based model, and rank-ordered logit model), and the visualization of ranking data with multidimensional preference analysis. Examples of the use of package pmr are given using a real ranking dataset from medical informatics, in which 566 Hong Kong physicians ranked the top five incentives (1: competitive pressures; 2: increased savings; 3: government regulation; 4: improved efficiency; 5: improved quality care; 6: patient demand; 7: financial incentives) to the computerization of clinical practice. The mean rank showed that item 4 is the most preferred item and item 3 is the least preferred item, and significance difference was found between physicians' preferences with respect to their monthly income. A multidimensional preference analysis identified two dimensions that explain 42% of the total variance. The first can be interpreted as the overall preference of the seven items (labeled as "internal/external"), and the second dimension can be interpreted as their overall variance of (labeled as "push/pull factors"). Various statistical models were fitted, and the best were found to be weighted distance-based models with Spearman's footrule distance. In this paper, we presented the R package pmr, the first package for analyzing and modeling ranking data. The package provides insight to users through descriptive statistics of ranking data. Users can also visualize ranking data by applying a thought

Farmers’ Adaptation Strategies to Climate Change and Their Implications in the Zou Department of South Benin

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Adégnandjou Mahouna Roland Fadina

2018-01-01

Full Text Available Climate change is a global phenomenon. Its impact on agricultural activities in developing countries has increased dramatically. Understanding how farmers perceive climate change and how they adapt to it is very important to the implementation of adequate policies for agricultural and food security. This paper aims to contribute to an understanding of farmers’ adaptation choices, determinants of the adaptation choices and the long-term implications of the adaptation choices. Data were collected from 120 respondents in the Zou Department of Benin. A binary logit model was used to analyze the factors influencing household decisions to adapt to climate change. Multinomial logistic regression analysis was estimated to analyze the factors influencing households’ choice of adaptation strategies to climate change. The results show that farmers have a developed perception of climate change. These changes are translated by rainfall disturbances (rainfall delays, early cessation, bad rainfall distribution etc., shortening of the small dry season, increasing of temperature and sometimes, violent winds. The survey reveals that Benin farmers adopt many strategies in response to climate change. These strategies include “Crop–livestock diversification and other good practices (mulching, organic fertilizer,” “Use of improved varieties, chemical fertilizers and pesticides,” “Agroforestry and perennial plantation” and “Diversification of income-generating activities.” The findings also reveal that most of the respondents use these strategies in combination. From the binary logit model, we know that “farming experience” and “educational level of household head” positively influence adaptation decisions. The result of the multinomial logit analysis shows that farming experience, educational level, farm size and gender have a significant impact on climate change adaptation strategies. Based on in-depth analysis of each strategy, we

Very short-term probabilistic forecasting of wind power with generalized logit-Normal distributions

DEFF Research Database (Denmark)

Pinson, Pierre

2012-01-01

and probability masses at the bounds. Both auto-regressive and conditional parametric auto-regressive models are considered for the dynamics of their location and scale parameters. Estimation is performed in a recursive least squares framework with exponential forgetting. The superiority of this proposal over......Very-short-term probabilistic forecasts, which are essential for an optimal management of wind generation, ought to account for the non-linear and double-bounded nature of that stochastic process. They take here the form of discrete–continuous mixtures of generalized logit–normal distributions...

An agent-based simulation model of patient choice of health care providers in accountable care organizations.

Science.gov (United States)

Alibrahim, Abdullah; Wu, Shinyi

2018-03-01

Accountable care organizations (ACO) in the United States show promise in controlling health care costs while preserving patients' choice of providers. Understanding the effects of patient choice is critical in novel payment and delivery models like ACO that depend on continuity of care and accountability. The financial, utilization, and behavioral implications associated with a patient's decision to forego local health care providers for more distant ones to access higher quality care remain unknown. To study this question, we used an agent-based simulation model of a health care market composed of providers able to form ACO serving patients and embedded it in a conditional logit decision model to examine patients capable of choosing their care providers. This simulation focuses on Medicare beneficiaries and their congestive heart failure (CHF) outcomes. We place the patient agents in an ACO delivery system model in which provider agents decide if they remain in an ACO and perform a quality improving CHF disease management intervention. Illustrative results show that allowing patients to choose their providers reduces the yearly payment per CHF patient by $320, reduces mortality rates by 0.12 percentage points and hospitalization rates by 0.44 percentage points, and marginally increases provider participation in ACO. This study demonstrates a model capable of quantifying the effects of patient choice in a theoretical ACO system and provides a potential tool for policymakers to understand implications of patient choice and assess potential policy controls.

ADDING A NEW STEP WITH SPATIAL AUTOCORRELATION TO IMPROVE THE FOUR-STEP TRAVEL DEMAND MODEL WITH FEEDBACK FOR A DEVELOPING CITY

Directory of Open Access Journals (Sweden)

Xuesong FENG, Ph.D Candidate

2009-01-01

Full Text Available It is expected that improvement of transport networks could give rise to the change of spatial distributions of population-related factors and car ownership, which are expected to further influence travel demand. To properly reflect such an interdependence mechanism, an aggregate multinomial logit (A-MNL model was firstly applied to represent the spatial distributions of these exogenous variables of the travel demand model by reflecting the influence of transport networks. Next, the spatial autocorrelation analysis is introduced into the log-transformed A-MNL model (called SPA-MNL model. Thereafter, the SPA-MNL model is integrated into the four-step travel demand model with feedback (called 4-STEP model. As a result, an integrated travel demand model is newly developed and named as the SPA-STEP model. Using person trip data collected in Beijing, the performance of the SPA-STEP model is empirically compared with the 4-STEP model. It was proven that the SPA-STEP model is superior to the 4-STEP model in accuracy; most of the estimated parameters showed statistical differences in values. Moreover, though the results of the simulations to the same set of assumed scenarios by the 4-STEP model and the SPA-STEP model consistently suggested the same sustainable path for the future development of Beijing, it was found that the environmental sustainability and the traffic congestion for these scenarios were generally overestimated by the 4-STEP model compared with the corresponding analyses by the SPA-STEP model. Such differences were clearly generated by the introduction of the new modeling step with spatial autocorrelation.

Modeling pedestrian gap crossing index under mixed traffic condition.

Science.gov (United States)

Naser, Mohamed M; Zulkiple, Adnan; Al Bargi, Walid A; Khalifa, Nasradeen A; Daniel, Basil David

2017-12-01

There are a variety of challenges faced by pedestrians when they walk along and attempt to cross a road, as the most recorded accidents occur during this time. Pedestrians of all types, including both sexes with numerous aging groups, are always subjected to risk and are characterized as the most exposed road users. The increased demand for better traffic management strategies to reduce the risks at intersections, improve quality traffic management, traffic volume, and longer cycle time has further increased concerns over the past decade. This paper aims to develop a sustainable pedestrian gap crossing index model based on traffic flow density. It focusses on the gaps accepted by pedestrians and their decision for street crossing, where (Log-Gap) logarithm of accepted gaps was used to optimize the result of a model for gap crossing behavior. Through a review of extant literature, 15 influential variables were extracted for further empirical analysis. Subsequently, data from the observation at an uncontrolled mid-block in Jalan Ampang in Kuala Lumpur, Malaysia was gathered and Multiple Linear Regression (MLR) and Binary Logit Model (BLM) techniques were employed to analyze the results. From the results, different pedestrian behavioral characteristics were considered for a minimum gap size model, out of which only a few (four) variables could explain the pedestrian road crossing behavior while the remaining variables have an insignificant effect. Among the different variables, age, rolling gap, vehicle type, and crossing were the most influential variables. The study concludes that pedestrians' decision to cross the street depends on the pedestrian age, rolling gap, vehicle type, and size of traffic gap before crossing. The inferences from these models will be useful to increase pedestrian safety and performance evaluation of uncontrolled midblock road crossings in developing countries. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

Development of a global computable general equilibrium model coupled with detailed energy end-use technology

International Nuclear Information System (INIS)

Fujimori, Shinichiro; Masui, Toshihiko; Matsuoka, Yuzuru

2014-01-01

Highlights: • Detailed energy end-use technology information is considered within a CGE model. • Aggregated macro results of the detailed model are similar to traditional model. • The detailed model shows unique characteristics in the household sector. - Abstract: A global computable general equilibrium (CGE) model integrating detailed energy end-use technologies is developed in this paper. The paper (1) presents how energy end-use technologies are treated within the model and (2) analyzes the characteristics of the model’s behavior. Energy service demand and end-use technologies are explicitly considered, and the share of technologies is determined by a discrete probabilistic function, namely a Logit function, to meet the energy service demand. Coupling with detailed technology information enables the CGE model to have more realistic representation in the energy consumption. The proposed model in this paper is compared with the aggregated traditional model under the same assumptions in scenarios with and without mitigation roughly consistent with the two degree climate mitigation target. Although the results of aggregated energy supply and greenhouse gas emissions are similar, there are three main differences between the aggregated and the detailed technologies models. First, GDP losses in mitigation scenarios are lower in the detailed technology model (2.8% in 2050) as compared with the aggregated model (3.2%). Second, price elasticity and autonomous energy efficiency improvement are heterogeneous across regions and sectors in the detailed technology model, whereas the traditional aggregated model generally utilizes a single value for each of these variables. Third, the magnitude of emissions reduction and factors (energy intensity and carbon factor reduction) related to climate mitigation also varies among sectors in the detailed technology model. The household sector in the detailed technology model has a relatively higher reduction for both energy

Com obtenir un Model de Regressió Logística Binària amb SPSS

Directory of Open Access Journals (Sweden)

Vanesa Berlanga-Silvente

2014-04-01

Full Text Available Els models de regressió logística són models estadístics en què es desitja conèixer la relació entre: una variable dependent qualitativa dicotòmica (regressió logística binària o binomial i una o més variables explicatives independents, o covariables, ja siguin qualitatives o quantitatives. També és possible una variable dependent qualitativa amb més de dos valors (regressió logística multinomial, encara que en aquesta fitxa ens centrarem en la regressió logística binària. En qualsevol cas, l'equació inicial del model és de tipus exponencial, si bé la seva transformació logarítmica (logit permet el seu ús com una funció lineal. L'objectiu primordial que resol aquesta tècnica és el de modelar com influeixen la probabilitat d'aparició d'un succés, habitualment dicotòmic, la presència o no de diversos factors, i el valor o nivell dels mateixos. Aquesta fitxa sobre la Regressió Logística Binària explica les opcions que té el programa estadístic SPSS (mètodes automàtics "per passos" i la interpretació dels principals resultats.

Macro-level vulnerable road users crash analysis: A Bayesian joint modeling approach of frequency and proportion.

Science.gov (United States)

Cai, Qing; Abdel-Aty, Mohamed; Lee, Jaeyoung

2017-10-01

This study aims at contributing to the literature on pedestrian and bicyclist safety by building on the conventional count regression models to explore exogenous factors affecting pedestrian and bicyclist crashes at the macroscopic level. In the traditional count models, effects of exogenous factors on non-motorist crashes were investigated directly. However, the vulnerable road users' crashes are collisions between vehicles and non-motorists. Thus, the exogenous factors can affect the non-motorist crashes through the non-motorists and vehicle drivers. To accommodate for the potentially different impact of exogenous factors we convert the non-motorist crash counts as the product of total crash counts and proportion of non-motorist crashes and formulate a joint model of the negative binomial (NB) model and the logit model to deal with the two parts, respectively. The formulated joint model is estimated using non-motorist crash data based on the Traffic Analysis Districts (TADs) in Florida. Meanwhile, the traditional NB model is also estimated and compared with the joint model. The result indicates that the joint model provides better data fit and can identify more significant variables. Subsequently, a novel joint screening method is suggested based on the proposed model to identify hot zones for non-motorist crashes. The hot zones of non-motorist crashes are identified and divided into three types: hot zones with more dangerous driving environment only, hot zones with more hazardous walking and cycling conditions only, and hot zones with both. It is expected that the joint model and screening method can help decision makers, transportation officials, and community planners to make more efficient treatments to proactively improve pedestrian and bicyclist safety. Published by Elsevier Ltd.

Logit Model of Computer-Based Data-Driven Creative Idea Generation in the Industry and Service Sectors

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S. N. Hojjati

2017-12-01

Full Text Available Organizational creativity and employee idea generation have become important and essential elements of an organization’s success, as creativity results to increased performance. The need of increased creativity is evident in industrial and service companies. The main idea behind this paper is to analyze and demonstrate if accessing various types of data in certain ways and/or situations affects creative idea generation by the people involved in different industrial/service sectors, considering that now most of the employees use digital data. The current paper discusses how seven different factors are related to digital data affect creativity.

INCLUSION OF THE LATENT PERSONALITY VARIABLE IN MULTINOMIAL LOGIT MODELS USING THE 16PF PSYCHOMETRIC TEST

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JORGE E. CÓRDOBA MAQUILÓN

2012-01-01

Full Text Available Los modelos de demanda de viajes utilizan principalmente los atributos modales y las características socioeconómicas como variables explicativas. También se ha establecido que las actitudes y percepciones influyen en el comportamiento de los usuarios. Sin embargo, las variables psicológicas del individuo condicionan la conducta del usuario. En este estudio se incluyó la variable latente personalidad, en la estimación del modelo híbrido de elección discreta, el cual constituye una buena alternativa para incorporar los efectos de los factores subjetivos. La variable latente personalidad se evaluó con la prueba psicométrica 16PF de validez internacional. El artículo analiza los resultados de la aplicación de este modelo a una población de empleados y docentes universitarios, y también propone un camino para la utilización de pruebas psicométricas en los modelos híbridos de elección discreta. Nuestros resultados muestran que los modelos híbridos que incluyen variables latentes psicológicas son superiores a los modelos tradicionales que ignoran los efectos de la conducta de los usuarios.

Financial gradualism and banking crises in North Africa region: an investigation by a panel logit model

OpenAIRE

KHATTAB, Ahmed; IHADIYAN, Abid

2017-01-01

Abstract. In order to overcome the troubles of the crisis in the seventies, North African countries have adopted financial liberalization policies to enhance their economic growth. Moreover, these policies have affected the stability of their banking systems. The purpose of this study is to test the impact of financial liberalization on the probability of appearance of banking crises which covers a sample of four countries of the North Africa region during the period 1970-2003 by using a pane...

A choice modelling analysis on the similarity between distribution utilities’ and industrial customers’ price and quality preferences

DEFF Research Database (Denmark)

Söderberg, Magnus

2008-01-01

The Swedish Electricity Act states that electricity distribution must comply with both price and quality requirements. In order to maintain efficient regulation it is necessary to firstly, define quality attributes and secondly, determine a customer's priorities concerning price and quality...... to evaluate the same twelve choice situations in which price and four specific quality attributes are varied. The preferences expressed by the utilities, and estimated by a random parameter logit, correspond quite well with the preferences expressed by the largest industrial customers. The preferences...

AN INTEGRATED MODELING FRAMEWORK FOR ENVIRONMENTALLY EFFICIENT CAR OWNERSHIP AND TRIP BALANCE

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Tao FENG

2008-01-01

Full Text Available Urban transport emissions generated by automobile trips are greatly responsible for atmospheric pollution in both developed and developing countries. To match the long-term target of sustainable development, it seems to be important to specify the feasible level of car ownership and travel demand from environmental considerations. This research intends to propose an integrated modeling framework for optimal construction of a comprehensive transportation system by taking into consideration environmental constraints. The modeling system is actually a combination of multiple essential models and illustrated by using a bi-level programming approach. In the upper level, the maximization of both total car ownership and total number of trips by private and public travel modes is set as the objective function and as the constraints, the total emission levels at all the zones are set to not exceed the relating environmental capacities. Maximizing the total trips by private and public travel modes allows policy makers to take into account trip balance to meet both the mobility levels required by travelers and the environmentally friendly transportation system goals. The lower level problem is a combined trip distribution and assignment model incorporating traveler's route choice behavior. A logit-type aggregate modal split model is established to connect the two level problems. In terms of the solution method for the integrated model, a genetic algorithm is applied. A case study is conducted using road network data and person-trip (PT data collected in Dalian city, China. The analysis results showed that the amount of environmentally efficient car ownership and number of trips by different travel modes could be obtained simultaneously when considering the zonal control of environmental capacity within the framework of the proposed integrated model. The observed car ownership in zones could be increased or decreased towards the macroscopic optimization

Factors Affecting Farmers’ Decision to Enter Agricultural Cooperatives Using Random Utility Model in the South Eastern Anatolian Region of Turkey

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Bahri Karlı

2006-10-01

Full Text Available Farmers’ decision and perceptions to be a member of agricultural cooperatives in the South Eastern Anatolian Region were investigated. Factors affecting the probability of joining the agricultural cooperatives were determined using binary logit model. The model released that most of variables such as education, high communication, log of gross income, farm size, medium and high technology variables play important roles in determining the probability of entrance. Small farmers are likely expected to join the agricultural cooperatives than the wealthier farmers are. Small farmers may wish to benefit cash at hand, input subsidies, and services provided by the agricultural cooperatives since the risks associated with intensive high-returning crops are high. Some important factors playing pole role in abstention of farmers towards agricultural cooperatives are gross income and some social status variables. In addition, conservative or orthodox farmers are less likely to join agricultural cooperatives than moderate farmers are. We also found that the direct government farm credit programs mainly should be objected to providing farmers to better access to capital markets and creating the opportunity to use with allocation of capital inputs via using modern technology.

Estimating preferences for local public services using migration data.

Science.gov (United States)

Dahlberg, Matz; Eklöf, Matias; Fredriksson, Peter; Jofre-Monseny, Jordi

2012-01-01

Using Swedish micro data, the paper examines the impact of local public services on community choice. The choice of community is modelled as a choice between a discrete set of alternatives. It is found that, given taxes, high spending on child care attracts migrants. Less conclusive results are obtained with respect to the role of spending on education and elderly care. High local taxes deter migrants. Relaxing the independence of the irrelevant alternatives assumption, by estimating a mixed logit model, has a significant impact on the results.

Benefits of improved water quality: a discrete choice analysis of freshwater recreational demands

OpenAIRE

R S Tay; P S McCarthy

1994-01-01

Discrete choice methodologies are increasingly being used to estimate multiple-sites recreational demands and evaluate the welfare effects of alternative environmental policies aimed at water quality improvements. In this study the authors use 1985 data on Indiana anglers to estimate a multinomial logit model of destination choice and compute the benefits of alternative water quality improvements. In general, the results indicate that anglers are reasonably sensitive to changes in water quali...

Banking Fragility in Colombia: An Empirical Analysis Based on Balance Sheets

OpenAIRE

Ignacio Lozano; Alexander Guarín

2014-01-01

In this paper, we study the empirical relationship between credit funding sources and the financial vulnerability of the Colombian banking system. We propose a statistical model to measure and predict banking-fragility episodes associated with credit funding sources classified into retail deposits and wholesale funds. We compute the probability of financial fragility for both the aggregated banking system and the individual banks. Our approach performs a Bayesian averaging of estimated logit ...

Do Monetary, Fiscal and Financial Institutions Really Matter for Inflation Targeting in Emerging Market Economies?

OpenAIRE

Seedwell Hove; Albert Touna Mama; Fulbert Tchana Tchana

2011-01-01

Most emerging market economies (EMEs) which have implemented inflation targeting (IT) have continued to experience large, frequent and sometimes persistent inflation target misses. At the same time these countries had reformed their institutional structures when implementing IT. In this paper we empirically study the importance of central bank independence, fiscal discipline and financial sector development for the achievement of inflation targets in EMEs using the panel ordered logit model. ...

Reimagine Procrastination: Music Preference and Health Habits as Factors on Self-Perceived Procrastination of Young People

OpenAIRE

Wei, Shu

2018-01-01

As the buzzword phenomenon, procrastination holds a continued need for a comprehensive examination of its nature and the associated factors. The presented study explores the potential relationship between music taste, life style and the youngsters' procrastination through quantitative modelling. To handle the big set of survey statistics and the uncertainty caused by the data missingness, the combined methods of factor analysis, multiple imputation (MI) and Ordered logit regression are employ...

Willingness to Pay Additional Water Rate and Irrigation Knowledge of Farmers in Dinar Karakuyu Irrigation Areas in Turkey

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Mevlüt Gül

2017-08-01

Full Text Available Water which has become commodity product which is an important product today. Turkey is not a water rich country. In this study, agricultural enterprises in the field of Irrigation Project in Dinar Karakuyu which was implemented in 1992 by DSI. The study analysed which factors affect the willingness to pay additional irrigation water rate with the help of logit model and the irrigation knowledge of farmers was determined by Likert scale. Dinar Karakuyu irrigation network has begun to lose the function in the region. It was supposed 100% irrigation rate but decreased by approximately 9% today. In this context, DSI (General Directorate of State Hydraulic Works plans to rehabilitation work in the same area. The main material of this study was data obtained from 67 agricultural enterprises through a survey covered by the Irrigation Rehabilitation Project in the province of Afyonkarahisar Karakuyu Dinar. The data was gathered with the help of questionnaires which were answered by farmers in Karakuyu Dinar region. The results indicated that 74.6% of farmers were willingness to pay additional water charge. The data were statistically analysed with the use of the logit model. The model results show that agricultural income, farmers’ educational level, computer ownership, attendance of agricultural training activities, family size and agricultural experience were positive factors affect farmers’ willingness to pay additional water fee.

Determinants of Agricultural Diversification in a Hotspot Area: Evidence from Colonist and Indigenous Communities in the Sumaco Biosphere Reserve, Ecuadorian Amazon

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Bolier Torres

2018-05-01

Full Text Available With data from a household survey covering migrant settlers and indigenous (Kichwa communities in the Sumaco Biosphere Reserve (SBR, this study analyses the drivers of agricultural diversification/specialisation, focusing on the role of ethnicity and the livelihood strategies (LS they follow. Data were collected using the Poverty and Environment Network methodology of the Center for International Forestry Research (CIFOR-PEN. In order to establish the drivers of agricultural diversification, the number of crops and the Shannon index of crops areas were used as the dependent variables in ordinary least square (OLS models, while a multinomial logit model (MLM was used to assess a household’s degree of diversification. The results of the OLS regression provides evidence supporting the notion that households, with Livestock-based and Wage-based livelihood strategies (LS are less diversified and more specialized than households with Crop-based LS. Ethnicity has a positive and significant effect on agricultural diversification, with Kichwa farms more diversified than those of their migrant colonist counterparts. The results of the multinomial logit model (MLM show that large Kichwa households, with Crop-based and Forest-based LS are more likely to adopt a highly diversified agricultural strategy. Based on these findings, we recommend a redirection of agricultural incentives, towards the adoption of diversified agricultural systems, as a strategy to promote more sustainable production systems in the Ecuadorian Amazon Region.

Incorporating Neighborhood Choice in a Model of Neighborhood Effects on Income.

Science.gov (United States)

van Ham, Maarten; Boschman, Sanne; Vogel, Matt

2018-05-09

Studies of neighborhood effects often attempt to identify causal effects of neighborhood characteristics on individual outcomes, such as income, education, employment, and health. However, selection looms large in this line of research, and it has been argued that estimates of neighborhood effects are biased because people nonrandomly select into neighborhoods based on their preferences, income, and the availability of alternative housing. We propose a two-step framework to disentangle selection processes in the relationship between neighborhood deprivation and earnings. We model neighborhood selection using a conditional logit model, from which we derive correction terms. Driven by the recognition that most households prefer certain types of neighborhoods rather than specific areas, we employ a principle components analysis to reduce these terms into eight correction components. We use these to adjust parameter estimates from a model of subsequent neighborhood effects on individual income for the unequal probability that a household chooses to live in a particular type of neighborhood. We apply this technique to administrative data from the Netherlands. After we adjust for the differential sorting of households into certain types of neighborhoods, the effect of neighborhood income on individual income diminishes but remains significant. These results further emphasize that researchers need to be attuned to the role of selection bias when assessing the role of neighborhood effects on individual outcomes. Perhaps more importantly, the persistent effect of neighborhood deprivation on subsequent earnings suggests that neighborhood effects reflect more than the shared characteristics of neighborhood residents: place of residence partially determines economic well-being.

Value of time determination for the city of Alexandria based on a disaggregate binary mode choice model

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Mounir Mahmoud Moghazy Abdel-Aal

2017-12-01

Full Text Available In the travel demand modeling field, mode choice is the most important decision that affects the resulted road congestion. The behavioral nature of the disaggregate models and the associated advantages of such models over aggregate models have led to their extensive use. This paper proposes a framework to determine the value of time (VoT for the city of Alexandria through calibrating a disaggregate linear-in parameter utility-based binary logit mode choice model of the city. The mode attributes (travel time and travel cost along with traveler attributes (car ownership and income were selected as the utility attributes of the basic model formulation which included 5 models. Three additional alternative utility formulations based on the transformation of the mode attributes including relative travel cost (cost divided by income and log (travel time and the combination of the two transformations together were introduced. The parameter estimation procedure was based on the likelihood maximization technique and was performed in EXCEL. Out of 20 models estimated, only 2 models are considered successful in terms of the parameters estimates correct signs and the magnitude of their significance (t-statistics value. The determination of the VoT serves also in the model validation. The best two models estimated the value of time at LE 11.30/hr and LE 14.50/hr with a relative error of +3.7% and +33.0%, respectively, of the hourly salary of LE 10.9/hr. The proposed two models prove to be sensitive to trip time and income levels as factors affecting the choice mechanism. The sensitivity analysis was performed and proved the model with higher relative error is marginally more robust. Keywords: Transportation modeling, Binary mode choice, Parameter estimation, Value of time, Likelihood maximization, Sensitivity analysis

A choice modelling analysis on the similarity between distribution utilities' and industrial customers' price and quality preferences

International Nuclear Information System (INIS)

Soederberg, Magnus

2008-01-01

The Swedish Electricity Act states that electricity distribution must comply with both price and quality requirements. In order to maintain efficient regulation it is necessary to firstly, define quality attributes and secondly, determine a customer's priorities concerning price and quality attributes. If distribution utilities gain an understanding of customer preferences and incentives for reporting them, the regulator can save a lot of time by surveying them rather than their customers. This study applies a choice modelling methodology where utilities and industrial customers are asked to evaluate the same twelve choice situations in which price and four specific quality attributes are varied. The preferences expressed by the utilities, and estimated by a random parameter logit, correspond quite well with the preferences expressed by the largest industrial customers. The preferences expressed by the utilities are reasonably homogenous in relation to forms of association (private limited, public and trading partnership). If the regulator acts according to the preferences expressed by the utilities, smaller industrial customers will have to pay for quality they have not asked for. (author)

Modelo de demanda para un tren de pasajeros entre Tunja y Bogotá

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Luis Gabriel Márquez

2009-11-01

Full Text Available Este artículo presenta los resultados de una encuesta de preferencias declaradas en un experimento de elección discreta, diseñado para examinar la demanda potencial de un nuevo sistema de transporte de pasajeros tipo tren entre Tunja y Bogotá. El estudio investiga acerca del comportamiento en la elección de tres modos de transporte: bus, tren y auto. Cada modo fue representado en términos del costo, tiempo de viaje e intervalo de tiempo entre despachos con un modelo logit mixto que incluye para los individuos la variable asiduidad. El modelo se utilizó para experimentar con distintos escenarios y se encontró para cada uno de ellos el reparto modal correspondiente. / This paper presents the results of stated-preference in a discrete choice experiments designed to examine the potential demand for a new type of passenger train between Tunja and Bogotá. The study investigates choice behaviour between three modes of transportation: bus, train and car. Each mode is represented in terms of cost, travel time and headway with a mixed logit model, which includes regularly for individuals. The model was used to experiment with different scenarios, finding the modal split for each.

Valuing attributes of enhanced traffic information: an experience in Kolkata

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D. Basu

2007-10-01

Full Text Available Most of the traffic information considers a single item like travel time or delay. In the present work, enhanced traffic information displaying instantaneous travel time and its variation from the previous interval to the present, is considered. An initial investigation is made on the effectiveness of such traffic information on route choice behavior of trip makers by valuation of attributes of the traffic information. Taking a case study of two urban corridors in the Kolkata metro city, India, the valuation is done separately for private car and taxi trip makers. The stated preference (choice based data collected from trip makers are analyzed using both multinomial logit (MNL and mixed logit (ML modeling techniques. Assuming sparsely used constrained triangular distribution of random parameters, two different types of ML model are developed: one with independent choice sets and the other one by accounting heterogeneity around the mean of random parameter(s. Both family income and trip purpose are found to decompose heterogeneity around the mean estimate(s. The values of travel time and their variation presented in the paper encourage further investigation on such type of traffic information for management of congestion on alternative urban corridors both spatially and temporally.

Energy efficiency barriers in commercial and industrial firms in Ukraine: An empirical analysis

International Nuclear Information System (INIS)

Hochman, Gal; Timilsina, Govinda R.

2017-01-01

Improvement in energy efficiency is one of the main options to reduce energy demand and greenhouse gas emissions. However, large-scale deployment of energy-efficient technologies is constrained by several factors. Employing a survey of 509 industrial and commercial firms throughout Ukraine and a generalized ordered logit model, we quantified the economic, behavioral, and institutional barriers that may impede the deployment of energy-efficient technologies. Our analysis shows that behavioral barriers resulted from lack of information, knowledge, and awareness are major impediments to the adoption of energy-efficient technologies in Ukraine, and that financial barriers may further impede investments in these technologies especially for small firms. This suggests that carefully targeted information provisions and energy audits will enhance Ukrainian firms' investments in energy-efficient technologies to save energy consumption, improve productivity, and reduce carbon emissions from the productive sectors. - Highlights: • Employing a survey of 509 industrial and commercial firms throughout Ukraine • A generalized ordered logit model is used in the analysis. • The paper quantifies the economic, behavioral, and institutional barriers to energy-efficient technologies. • Behavioral barriers are major impediments to the adoption of energy-efficient technologies. • Financial barriers may further impede investments in these technologies especially for small firms.

Influence of Immunology Knowledge on Healthcare and Healthy Lifestyle.

Science.gov (United States)

Abu Kassim, Noor Lide; Saleh Huddin, Afiqah Binti; Daoud, Jamal Ibrahim; Rahman, Mohammad Tariqur

2016-01-01

Completing a course in Immunology is expected to improve health care knowledge (HCK), which in turn is anticipated to influence a healthy lifestyle (HLS), controlled use of health care services (HCS) and an awareness of emerging health care concerns (HCC). This cross-sectional study was designed to determine whether these interrelationships are empirically supported. Participants involved in this study were government servants from two ministries in Malaysia (n = 356) and university students from a local university (n = 147). Participants were selected using the non-random purposive sampling method. Data were collected using a self-developed questionnaire, which had been validated in a pilot study involving similar subjects. The questionnaire items were analyzed using Rasch analysis, SPSS version 21 and AMOS version 22. Results have shown that participants who followed a course in Immunology (CoI) had a higher primary HCK (Mean = 0.69 logit, SD = 1.29 logits) compared with those who had not (Mean = -0.27logit, SD = 1.26 logits). Overall, there were significant correlations among the HLS, the awareness of emerging HCC, and the controlled use of HCS (p Immunology at various levels of education and increasing the public awareness of emerging HCC might help to improve population health en masse. In addition, further investigations on the factors affecting HLS is required to provide a better understanding on the relationship between primary HCK and HLS.

Community Forestry as Perceived by Local People Around Cross River National Park, Nigeria

Science.gov (United States)

Ezebilo, Eugene E.

2012-01-01

The prior identification of local people's preferences for conservation-development projects will help gear nature-conservation strategies toward the needs of different groups of local people. This will help policy-makers in designing a more acceptable and effective conservation strategy. This article reports a study of local perceptions of a community forestry project that aims to help improve the design as well as local acceptance of the project. The data originated from personal interviews conducted in communities around Okwangwo Division of the Cross River National Park in southeast Nigeria and were analysed using ordered logit and binary logit models. The results showed that >50% of the respondents were satisfied with the community forestry project. The respondents' perceptions were mainly influenced by education, age, gender, and willingness to contribute money to tourism as well as the contributions of cocoa, banana, and afang ( Gnetum africanum) to the respondents' income. The results from this study have important implications for nature conservation in Nigeria and potentially other conservation contexts across the developing world.

Preference elicitation approach for measuring the willingness to pay for liver cancer treatment in Korea

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Donghun Cho

2015-09-01

Full Text Available Background/AimsThe Korean government has expanded the coverage of the national insurance scheme for four major diseases: cancers, cardiovascular diseases, cerebrovascular diseases, and rare diseases. This policy may have a detrimental effect on the budget of the national health insurance agency. Like taxes, national insurance premiums are levied on the basis of the income or wealth of the insured.MethodsUsing a preference elicitation method, we attempted to estimate how much people are willing to pay for insurance premiums that would expand their coverage for liver cancer treatment.ResultsWe calculated the marginal willingness to pay (MWTP through the marginal rate of substitution between the two attributes of the insurance premium and the total annual treatment cost by adopting conditional logit and mixed logit models.ConclusionsThe effects of various other terms that could interact with socioeconomic status were also estimated, such as gender, income level, educational attainment, age, employment status, and marital status. The estimated MWTP values of the monthly insurance premium for liver cancer treatment range from 4,130 KRW to 9,090 KRW.

DETERMINANTS OF CHOICE OF CROP VARIETY AS CLIMATE CHANGE ADAPTATION OPTION IN ARID REGIONS OF ZIMBABWE

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James Zivanomoyo

2013-03-01

Full Text Available Impacts of climate change in developing countries remain poorly understood because few studies have successfully analyses the overall impact of climate on developing country economies. Agricultural growth is widely viewed as an effective and most important way to reduce poverty in developing countries which are hardly hit by the adverse effects of climate change (Datt and Ravallion, 1996. Despite this knowledge the main challenge is how to increase agricultural productivity to improve household welfare and increase food security in these changing and challenging climatic conditions. This study used the multinomial logit model to analyse the determinants of farmers' choice of crop variety in the face of climate change. The estimation of the multinomial logit was done by using the sorghum variety options as dependent variable and where farmers grow other crop different from sorghum as the reference state. Results show that the key determinants of choosing crop variety are; the price of existing crop variety, level of education of farmers, the size of the farms, government policies and incentives and credit availability.

Simulating Land-Use Change using an Agent-Based Land Transaction Model

Science.gov (United States)

Bakker, M. M.; van Dijk, J.; Alam, S. J.

2013-12-01

obviously an important driver for nature expansion, but without a strict zoning plan imposed by a government, it is difficult to achieve a continuous, defragmented nature area. Lastly, the model suggests that with time the trend in ever-increasing farm sizes is gradually levelling out. The decision rules that determine the behaviours of the individual agents in the model (selling land, buying land, or none of the two) are calibrated on historical census records, using multi-nominal logistic regression. Because estimating who will sell and who will buy can only be done with a limited certainty, our model reproduces the volatility / uncertainty in who will do what and when. This makes that each specific future scenario can have numerous realizations of reality. Our stakeholders (including, besides policy makers, also local farmers and nature organizations) indicate that this aspect of the model strongly contributes to its credibility. Nevertheless, within different scenarios certain (spatial) trends are distinguishable, so that the model is -besides credible - also useful for exploring future trends.

Electoral system, pesonal votes, and party choice

DEFF Research Database (Denmark)

Thomsen, Søren Risbjerg

Using local elections in Denmark as an example this paper shows that individual party choice is influenced both by individual level, municipality level, and national level characteristics. Some hypotheses about the effects of the electoral system on personal votes derived from a theory by Carey...... & Shugart (1995) are first tested using a fixed-effects model. The effect of the personal reputation of the candidates, measured by personal votes, on party choice is then tested using a multilevel multinomial logit model suggested by Rabe-Hesketh and Skrondal (2008). The paper shows that both the electoral...

Aggravating andmitigating factors associated with cyclist injury severity in Denmark

DEFF Research Database (Denmark)

Kaplan, Sigal; Vavatsoulas,, Konstantinos; Prato, Carlo Giacomo

2014-01-01

severity on Danish roads by examining a comprehensive set of accidents involving a cyclist and a collision partner between 2007 and 2011. Method: This study estimates a generalized ordered logit model of the severity of cyclist injuries because of its ability to accommodate the ordered-response nature...... of severity while relaxing the proportional odds assumption. Results: Model estimates show that cyclist fragility (children under 10 years old and elderly cyclists over 60 years of age) and cyclist intoxication are aggravating individual factors,while helmet use is a mitigating factor. Speed limits above 70...

CATDAT : A Program for Parametric and Nonparametric Categorical Data Analysis : User's Manual Version 1.0, 1998-1999 Progress Report.

Energy Technology Data Exchange (ETDEWEB)

Peterson, James T.

1999-12-01

Natural resource professionals are increasingly required to develop rigorous statistical models that relate environmental data to categorical responses data. Recent advances in the statistical and computing sciences have led to the development of sophisticated methods for parametric and nonparametric analysis of data with categorical responses. The statistical software package CATDAT was designed to make some of these relatively new and powerful techniques available to scientists. The CATDAT statistical package includes 4 analytical techniques: generalized logit modeling; binary classification tree; extended K-nearest neighbor classification; and modular neural network.

CATDAT - A program for parametric and nonparametric categorical data analysis user's manual, Version 1.0

International Nuclear Information System (INIS)

Peterson, James R.; Haas, Timothy C.; Lee, Danny C.

2000-01-01

Natural resource professionals are increasingly required to develop rigorous statistical models that relate environmental data to categorical responses data. Recent advances in the statistical and computing sciences have led to the development of sophisticated methods for parametric and nonparametric analysis of data with categorical responses. The statistical software package CATDAT was designed to make some of these relatively new and powerful techniques available to scientists. The CATDAT statistical package includes 4 analytical techniques: generalized logit modeling; binary classification tree; extended K-nearest neighbor classification; and modular neural network

Effect of Advertising on the Brand Loyalty of Cosmetic Products among College Students

OpenAIRE

Ababio, Abraham Gyamfi; Yamoah, Emmanuel Erastus

2016-01-01

This study explored the relationship between advertising and brand loyalty of cosmetic products. The multinomial logit model was used to ascertain the effect of advertising on different loyalty profiles for cosmetic products among college students. Based on a survey of 200 Ghanaian students drawn randomly, findings indicated that advertising plays no significant role on college students’ loyalty for cosmetic products. It can be argued, however, that the most promiscuous buyer is more amenable...

Determinants of Fresh Fish Purchasing Behavior Among Malaysian Consumers

OpenAIRE

Abdullahi Farah Ahmed; Zainalabidin Mohamed and Mohd Mansor Ismail

2011-01-01

The study investigates demographic and attitudinal characteristics that can affect the purchase decisions of marine fish among Malaysian consumers. A survey was conducted on Kuala Lumpur households using structured questionnaires. Seven hundred respondents were randomly interviewed with regard to their buying behaviour pattern, attitude and perception on fresh marine fish consumption. The data were analyzed using a logit binary model. It was found that the size and income of the households, g...

Television Advertising and Soda Demand

OpenAIRE

Lopez, Rigoberto A.; Liu, Yizao; Zhu, Chen

2012-01-01

This study examines the effects of television advertising on consumer demand for carbonated soft drinks using a random coefficients logit model (BLP) with household and advertising data from seven U.S. cities over a three year period. We find that advertising decreases the price elasticity of demand, indicating that advertising plays predominantly a persuasive, therefore anti-competitive role in this market. Further results show that brand spillover effects are significant and that measuring ...

The Renewables Influence on Market Splitting: the Iberian Spot Electricity Market

OpenAIRE

Nuno Carvalho Figueiredo; Patrícia Pereira da Silva; Pedro Cerqueira

2014-01-01

This paper aims to assess the influence of wind power generation on the market splitting behaviour of the Iberian electricity spot markets. We use logit models to express the probability response for market splitting of day-ahead spot electricity prices together with explanatory variables like, wind speed, available transmission capacity and electricity demand. The results show that the probability of market splitting increases with the increase of wind power generation. The European intercon...

A Panel Analysis Of UK Industrial Company Failure

OpenAIRE

Natalia Isachenkova; John Hunter

2002-01-01

We examine the failure determinants for large quoted UK industrials using a panel data set comprising 539 firms observed over the period 1988-93. The empirical design employs data from company accounts and is based on Chamberlain’s conditional binomial logit model, which allows for unobservable, firm-specific, time-invariant factors associated with failure risk. We find a noticeable degree of heterogeneity across the sample companies. Our panel results show that, after controll...

Dispositional Employability and Online Training Purchase. Evidence from Employees' Behavior in Spain

OpenAIRE

Torrent-Sellens, Joan; Ficapal-Cus?, Pilar; Boada-Grau, Joan

2016-01-01

This article explores the relationship between dispositional employability and online training purchase. Through a sample of 883 employees working for enterprises in Spain, and a using principal component analysis and binomial logit probabilistic models, the research revealed two main results. First, it was found that dispositional employability is characterized by five factors: “openness to changes at work,” “career motivation and work resilience,” “work and career proactivity,” “optimism an...

Female labour force participation in MENA's manufacturing sector: The implications of firm-related and national factors

OpenAIRE

Fakih, Ali; Ghazalian, Pascal L.

2013-01-01

The Middle East and North Africa (MENA) region falls behind several other geo-economic regions in terms of women's participation rates in the labour market. This paper examines the implications of firm-related and national factors for Female Labour Force Participation (FLFP) rates in manufacturing firms located in the MENA region. The empirical investigation uses data derived from the World Bank's Enterprise Surveys database and applies fractional logit models to carry out the estimations. Th...

Determinants of the probability of adopting quality protein maize (QPM) technology in Tanzania: A logistic regression analysis

OpenAIRE

Gregory, T.; Sewando, P.

2013-01-01

Adoption of technology is an important factor in economic development. The thrust of this study was to establish factors affecting adoption of QPM technology in Northern zone of Tanzania. Primary data was collected from a random sample of 120 smallholder maize farmers in four villages. Data collected were analysed using descriptive and quantitative methods. Logit model was used to determine factors that influence adoption of QPM technology. The regression results indicated that education of t...

Long Work Hours: Volunteers and Conscripts

OpenAIRE

Robert Drago; Mark Wooden; David Black

2006-01-01

Panel data from Australia are used to study the prevalence of work hours mismatch among long hours workers and, more importantly, how that mismatch persists and changes over time, and what factors are associated with these changes. Particular attention is paid to the roles played by household debt, ideal worker characteristics and gender. Both static and dynamic multinomial logit models are estimated, with the dependent variable distinguishing long hours workers from other workers, and within...

The Influence of Higher Moments of Earnings Distributions on Career Decisions.

OpenAIRE

Flyer, Fredrick A

1997-01-01

A model where choice of occupation is sequential is applied to college graduates from the National Longitudinal Study of High School Class of 1972 to investigate how higher moments of occupational earnings distributions influence initial field of work. Individual specific life-cycle earnings projections that incorporate option values of occupational mobility are generated, and the relationship between these pay measures and choice of initial occupation is explored within a multinomial logit f...

Dispositional employability and online training purchase. Evidence from employees' behavior in Spain

OpenAIRE

BOADA GRAU, JOAN; Joan Torrent-Sellens; Pilar Ficapal-Cusí

2016-01-01

DOI: 10.3389/fpsyg.2016.00831 URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4887487/ Filiació URV: SI This article explores the relationship between dispositional employability and online training purchase. Through a sample of 883 employees working for enterprises in Spain, and a using principal component analysis and binomial logit probabilistic models, the research revealed two main results. First, it was found that dispositional employability is characterized by five factors: ...

Tendency of corruption and its determinants among public servants: A case study on Malaysia

OpenAIRE

Duasa, Jarita

2008-01-01

This study attempts to analyze determinants of corruption tendency on a single country, namely Malaysia, using cross-sectional data. Using survey questions on sample of respondents in two states of Malaysia, Kuala Lumpur and Selangor, data are collected and logit model is developed for estimation. The results from the regression on sample indicate that age negatively contributes to corruption tendency among government servants. The results also show that there are two departments, namely Poli...

"Choice of Air Cargo Transshipment Airport: An Application to Air Cargo Traffic to/from Northeast Asia"

OpenAIRE

Hiroshi Ohashi; Tae-Seung Kim; Tae Hoon Oum; Chunyan Yu

2004-01-01

Based on a unique data set of 760 air cargo transshipment routings to/from the Northeast Asian region in 2000, this paper applies an aggregate form of multinomial logit model to identify the critical factors influencing air cargo transshipment route choice decisions. The analysis focuses on the trade-off between monetary cost and time cost while considering other variables relevant for choice of transshipment airport. The estimation method considers the presence of unobserved attributes, and ...

Climate Change Adaptation via U.S. Land Use Transitions: A Spatial Econometric Analysis

OpenAIRE

Cho, Sung Ju; McCarl, Bruce A.; Wu, Ximing

2015-01-01

Climate change, coupled with biofuels development and other factors may well be changing US land usage patterns. We use a spatial econometric approach to estimate the drivers of US land use transitions in recent years. We consider transitions between six major land uses: agricultural land, forest, grassland, water, urban, and other uses. To examine drivers, we use a two-step linearized, spatial, multinomial logit model and estimate land use transition probabilities. Our results indicate that ...

Factors influencing the perception of organic certification logos in Turkey

OpenAIRE

Karahan Uysal, Ö.; Miran, B.; Abay, C.; Boyaci, M.; Janssen, M.; Hamm, U.

2013-01-01

Consumers’ perceptions on organic certification logos and the factors influencing these perceptions were explored. Data from surveys conducted in major cities of Turkey revealed that organic food consumers had little knowledge about logos, although the declared level of trust in organic logos was high. According to ordered logit models, consumer’s perceptions on organic certification logos were influenced by purchasing frequency and weight of organic foods in total food consumption. Dummy v...

Effective Exchange Rate Classifications and Growth

OpenAIRE

Justin M. Dubas; Byung-Joo Lee; Nelson C. Mark

2005-01-01

We propose an econometric procedure for obtaining de facto exchange rate regime classifications which we apply to study the relationship between exchange rate regimes and economic growth. Our classification method models the de jure regimes as outcomes of a multinomial logit choice problem conditional on the volatility of a country's effective exchange rate, a bilateral exchange rate and international reserves. An `effective' de facto exchange rate regime classification is then obtained by as...

Location-Price Competition in Airline Networks

Directory of Open Access Journals (Sweden)

H. Gao

2014-01-01

Full Text Available This paper addresses location-then-price competition in airline market as a two-stage game of n players on the graph. Passenger’s demand distribution is described by multinomial logit model. Equilibrium in price game is computed through best response dynamics. We solve location game using backward induction, knowing that airlines will choose prices from equilibrium for the second-stage game. Some numerical results for airline market under consideration are presented.

Do media consumers really dislike advertising? An empirical assessment of the role of advertising in print media markets

OpenAIRE

Kaiser, U; Song, M

2009-01-01

This paper uses data on German consumer magazines observed between 1992 and 2004 to analyze the extent to which consumers (dis-)like advertising. We estimate logit demand models separately for the six most important magazine segments in terms of circulation. We find little evidence for readers disliking advertising. On the contrary, we show that readers in many magazine segments appreciate advertising. Readers of Women's magazines, Business and politics magazines as well as Car magazines ...

Modelling the spatio-temporal distribution of age-1 bay of biscay anchovy (Engraulis encrasicolus) at spawning time [Distribución espacio-temporal de la edad 1 de anchoa del golfo de Bizkaia (Engraulis Encrasicolus) en el momento de puesta

KAUST Repository

Ibaibarriaga, Leire

2013-09-13

To efficiently manage and maintain fish stock abundance and age structure, it is necessary to understand variability in its spatial distribution. The main objective of this study was to describe the demographic structure of the Bay of Biscay anchovy during the main spawning period based on adult samples from 15 daily egg production method surveys. The proportion of age-1 individuals was modelled using generalized additive models with a binomial distribution and a logit link in relation to geographical and environmental covariates. The possibility of obtaining different models depending on the average age-1 proportion (low or high) was also explored. In general, age-1 individuals were found in shallow waters close to the coast, especially associated with the Gironde and Adour river plumes, whereas older individuals were prevalent on the shelf break and in oceanic waters. However, in years with a high age-1 proportion the younger individuals were also dominant in oceanic waters. These results could be used for management purposes, such as defining protected areas for particular age groups.

Work Intensity of Households: Multinomial Logit Analysis and Correspondence Analysis for Slovak Republic

Directory of Open Access Journals (Sweden)

Erik Šoltés

2018-03-01

Full Text Available Exclusion from the labour market is a serious social problem that is also addressed by the Europe 2020 strategy. While in the past the attention of statisticians and sociologists in the fight against poverty and social exclusion has concentrated mainly on income poverty and material deprivation, in recent times many studies and analyses are much more focused on work intensity as well. Households that use their work potential to less than 20%, have a very low work intensity, and members of such households are included into the population of people who are at risk of poverty or social exclusion. Moreover, the low use of labour potential of households significantly increases the risk of income poverty and the threat of material deprivation. This article provides an analysis of work intensity levels of Slovak households depending on the factors that are monitored by the EU-SILC 2015. The impact of relevant factors is quantified by correspondence analysis and by multinomial logistic regression model.

Modeling Types of Pedal Applications Using a Driving Simulator.

Science.gov (United States)

Wu, Yuqing; Boyle, Linda Ng; McGehee, Daniel; Roe, Cheryl A; Ebe, Kazutoshi; Foley, James

2015-11-01

The aim of this study was to examine variations in drivers' foot behavior and identify factors associated with pedal misapplications. Few studies have focused on the foot behavior while in the vehicle and the mishaps that a driver can encounter during a potentially hazardous situation. A driving simulation study was used to understand how drivers move their right foot toward the pedals. The study included data from 43 drivers as they responded to a series of rapid traffic signal phase changes. Pedal application types were classified as (a) direct hit, (b) hesitated, (c) corrected trajectory, and (d) pedal errors (incorrect trajectories, misses, slips, or pressed both pedals). A mixed-effects multinomial logit model was used to predict the likelihood of one of these pedal applications, and linear mixed models with repeated measures were used to examine the response time and pedal duration given the various experimental conditions (stimuli color and location). Younger drivers had higher probabilities of direct hits when compared to other age groups. Participants tended to have more pedal errors when responding to a red signal or when the signal appeared to be closer. Traffic signal phases and locations were associated with pedal response time and duration. The response time and pedal duration affected the likelihood of being in one of the four pedal application types. Findings from this study suggest that age-related and situational factors may play a role in pedal errors, and the stimuli locations could affect the type of pedal application. © 2015, Human Factors and Ergonomics Society.

Biomarker Detection in Association Studies: Modeling SNPs Simultaneously via Logistic ANOVA

KAUST Repository

Jung, Yoonsuh

2014-10-02

In genome-wide association studies, the primary task is to detect biomarkers in the form of Single Nucleotide Polymorphisms (SNPs) that have nontrivial associations with a disease phenotype and some other important clinical/environmental factors. However, the extremely large number of SNPs comparing to the sample size inhibits application of classical methods such as the multiple logistic regression. Currently the most commonly used approach is still to analyze one SNP at a time. In this paper, we propose to consider the genotypes of the SNPs simultaneously via a logistic analysis of variance (ANOVA) model, which expresses the logit transformed mean of SNP genotypes as the summation of the SNP effects, effects of the disease phenotype and/or other clinical variables, and the interaction effects. We use a reduced-rank representation of the interaction-effect matrix for dimensionality reduction, and employ the L 1-penalty in a penalized likelihood framework to filter out the SNPs that have no associations. We develop a Majorization-Minimization algorithm for computational implementation. In addition, we propose a modified BIC criterion to select the penalty parameters and determine the rank number. The proposed method is applied to a Multiple Sclerosis data set and simulated data sets and shows promise in biomarker detection.

Biomarker Detection in Association Studies: Modeling SNPs Simultaneously via Logistic ANOVA

KAUST Repository

Jung, Yoonsuh; Huang, Jianhua Z.; Hu, Jianhua

2014-01-01

In genome-wide association studies, the primary task is to detect biomarkers in the form of Single Nucleotide Polymorphisms (SNPs) that have nontrivial associations with a disease phenotype and some other important clinical/environmental factors. However, the extremely large number of SNPs comparing to the sample size inhibits application of classical methods such as the multiple logistic regression. Currently the most commonly used approach is still to analyze one SNP at a time. In this paper, we propose to consider the genotypes of the SNPs simultaneously via a logistic analysis of variance (ANOVA) model, which expresses the logit transformed mean of SNP genotypes as the summation of the SNP effects, effects of the disease phenotype and/or other clinical variables, and the interaction effects. We use a reduced-rank representation of the interaction-effect matrix for dimensionality reduction, and employ the L 1-penalty in a penalized likelihood framework to filter out the SNPs that have no associations. We develop a Majorization-Minimization algorithm for computational implementation. In addition, we propose a modified BIC criterion to select the penalty parameters and determine the rank number. The proposed method is applied to a Multiple Sclerosis data set and simulated data sets and shows promise in biomarker detection.

Measuring Health-Related Quality of Life in Strabismus: A Modification of the Adult Strabismus-20 (AS-20 Questionnaire Using Rasch Analysis.

Directory of Open Access Journals (Sweden)

Vijaya K Gothwal

Full Text Available To evaluate the psychometric properties of the Adult Strabismus-20 (AS-20- a health-related quality of life (HRQoL questionnaire in adults with strabismus, and if flawed, to revise the AS-20 and its subscales creating valid measurement scales.584 adults (meanage, 27.5 years with strabismus were recruited from an outpatient clinic at a South Indian tertiary eye care centre and were administered the AS-20 questionnaire.The AS-20 was translated and back translated into two Indian languages. The AS-20 and its two 10-item subscales - 'psychosocial' and 'function'were assessed separately for fit to the Rasch model, including an assessment of the rating scale, unidimensionality (by principal components analysis, measurement precision by person separation reliability, PSR, targeting, and differential item functioning (DIF; notable > 1.0 logits.Response categories were not used as intended, thereby, required re-organization and reducing their number from 5 to 3. The AS-20 had adequate measurement precision (PSR = 0.87 but lacked unidimensionality; however, deletion of the six multi-dimensionality causing items and an additional three misfitting items resulted in 11-item unidimensional questionnaire (AS-11. Two items failed to satisfy the model expectations in the 'psychosocial' subscale and were deleted - resulting in an 8-item unidimensional scale with adequate PSR (0.81 and targeting (0.23 logits. One item misfit in the 'function' subscale and was deleted-resulting in a 9 item Rasch-revised unidimensional subscale with acceptable PSR (0.80 and targeting (0.97 logits.None of the items displayed notable DIF by age, gender and level of education.The AS-11 and its two Rasch-revised subscales - 8-item psychosocial and 9-item function subscale may be more appropriate than the original AS-20 and its two 10-item subscales for use as unidimensional measures of HRQoL in adults with strabismus in India. Further work is required to establish the validity of the

Ecological Niche Modelling of the Bacillus anthracis A1.a sub-lineage in Kazakhstan

Science.gov (United States)

2011-01-01

Background Bacillus anthracis, the causative agent of anthrax, is a globally distributed zoonotic pathogen that continues to be a veterinary and human health problem in Central Asia. We used a database of anthrax outbreak locations in Kazakhstan and a subset of genotyped isolates to model the geographic distribution and ecological associations of B. anthracis in Kazakhstan. The aims of the study were to test the influence of soil variables on a previous ecological niche based prediction of B. anthracis in Kazakhstan and to determine if a single sub-lineage of B. anthracis occupies a unique ecological niche. Results The addition of soil variables to the previously developed ecological niche model did not appreciably alter the limits of the predicted geographic or ecological distribution of B. anthracis in Kazakhstan. The A1.a experiment predicted the sub-lineage to be present over a larger geographic area than did the outbreak based experiment containing multiple lineages. Within the geographic area predicted to be suitable for B. anthracis by all ten best subset models, the A1.a sub-lineage was associated with a wider range of ecological tolerances than the outbreak-soil experiment. Analysis of rule types showed that logit rules predominate in the outbreak-soil experiment and range rules in the A1.a sub-lineage experiment. Random sub-setting of locality points suggests that models of B. anthracis distribution may be sensitive to sample size. Conclusions Our analysis supports careful consideration of the taxonomic resolution of data used to create ecological niche models. Further investigations into the environmental affinities of individual lineages and sub-lineages of B. anthracis will be useful in understanding the ecology of the disease at large and small scales. With model based predictions serving as approximations of disease risk, these efforts will improve the efficacy of public health interventions for anthrax prevention and control. PMID:22152056

Precision of radioimmunoassays by various types of data processing systems

International Nuclear Information System (INIS)

Ujiie, Morimichi

1979-01-01

The following are the result of the investigation of the precision of radioimmunoassays by various types of data processing systems presently performed in Japan. Chose 50 facilities, where 10 facilities of clinical laboratories were included. Tested 334, 485 cases per month, which corresponds to 40% of the total number of the cases treated all over the country. It was known that the data of 74% of all facilities and 94% of all tests were being processed by computing machines. In 66 times of data processing of insulin and T3 measurements, 32 were performed by the hyperbola method, 11 by the log-logit curve method of secondary degree, 9 by the logistic curve method and 8 by the log-logit curve method of first degree. Practically in more than 90% of all cases were processed by these 4 types of curve methods. In insulin measurements of many standard points (8 points), favourable results could be obtained by the logistic curve method. On the contrary, in T3 measurements of fewer standard points (5 points), the results from the method of log-logit curve of secondary degree were good. Favourable results of both insulin and T3 measurements could be obtained by the hyperbola method. While, in the insulin measurement by the method of log-logit curve of first degree, the values were a bit lower in the higher and lower concentration ranges, and 3 -- 4% higher than the actual values in the middle concentration range. (author)

Towards an energy end use model

International Nuclear Information System (INIS)

Smith Fontana, Raul

2003-01-01

The general equilibrium energy end use model proposed, uses linear programming as te basic and central element to optimization of variables defined in the economic and energy areas of the country related to a four factors structure: Energy, Raw Material, Capital and Labor, and related to the sectors: Residential, Commercial, Industrial, Transportation and Import/Export. Input-Output coefficients are defined in an input-output matrix of processes representing the supply of Electricity (generated by nuclear- not available in Chile-hydro, gas, fuel-oil and coal), Petroleum, Imported Natural Gas (transported and distributed) National Natural Gas, LPG, Coal, Wood and representing a demand of Residential, Commercial, Industrial, Transportation and Import/Export. There is an interaction of the final demand composition, the prices of capital, labor and taxes with the levels of operation for each process and the prices of goods and services. In addition to the prices of fuels for each annual period, to the supply and demand of energy and to the total demand it can forecast the optimum coefficients of the final demand. If the data to be collected result reasonably complete and consistent, the model will be useful for planning. A special effort should be placed in specifying a certain number of typical energy activities, the available options for fuels, the selection of them attending rational market decisions and conservation according to well known economical criteria of substitution. To simulate the process of options selection given by the activities and to allow substitutions, it is possible to introduce the logit function characterized by a Weibull distribution and the generalized substitution function characterized by the constant electricity. The model would allow, assuming differents scenario, to visualize general policies in the penetration of energy technologies. To study the penetration of electric energy generated by nuclear, in which the country does not have

Normal tissue complication probability modeling of radiation-induced hypothyroidism after head-and-neck radiation therapy.

Science.gov (United States)

Bakhshandeh, Mohsen; Hashemi, Bijan; Mahdavi, Seied Rabi Mehdi; Nikoofar, Alireza; Vasheghani, Maryam; Kazemnejad, Anoshirvan

2013-02-01

To determine the dose-response relationship of the thyroid for radiation-induced hypothyroidism in head-and-neck radiation therapy, according to 6 normal tissue complication probability models, and to find the best-fit parameters of the models. Sixty-five patients treated with primary or postoperative radiation therapy for various cancers in the head-and-neck region were prospectively evaluated. Patient serum samples (tri-iodothyronine, thyroxine, thyroid-stimulating hormone [TSH], free tri-iodothyronine, and free thyroxine) were measured before and at regular time intervals until 1 year after the completion of radiation therapy. Dose-volume histograms (DVHs) of the patients' thyroid gland were derived from their computed tomography (CT)-based treatment planning data. Hypothyroidism was defined as increased TSH (subclinical hypothyroidism) or increased TSH in combination with decreased free thyroxine and thyroxine (clinical hypothyroidism). Thyroid DVHs were converted to 2 Gy/fraction equivalent doses using the linear-quadratic formula with α/β = 3 Gy. The evaluated models included the following: Lyman with the DVH reduced to the equivalent uniform dose (EUD), known as LEUD; Logit-EUD; mean dose; relative seriality; individual critical volume; and population critical volume models. The parameters of the models were obtained by fitting the patients' data using a maximum likelihood analysis method. The goodness of fit of the models was determined by the 2-sample Kolmogorov-Smirnov test. Ranking of the models was made according to Akaike's information criterion. Twenty-nine patients (44.6%) experienced hypothyroidism. None of the models was rejected according to the evaluation of the goodness of fit. The mean dose model was ranked as the best model on the basis of its Akaike's information criterion value. The D(50) estimated from the models was approximately 44 Gy. The implemented normal tissue complication probability models showed a parallel architecture for the

Normal Tissue Complication Probability Modeling of Radiation-Induced Hypothyroidism After Head-and-Neck Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Bakhshandeh, Mohsen [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Hashemi, Bijan, E-mail: bhashemi@modares.ac.ir [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Mahdavi, Seied Rabi Mehdi [Department of Medical Physics, Faculty of Medical Sciences, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Nikoofar, Alireza; Vasheghani, Maryam [Department of Radiation Oncology, Hafte-Tir Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Kazemnejad, Anoshirvan [Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

2013-02-01

Purpose: To determine the dose-response relationship of the thyroid for radiation-induced hypothyroidism in head-and-neck radiation therapy, according to 6 normal tissue complication probability models, and to find the best-fit parameters of the models. Methods and Materials: Sixty-five patients treated with primary or postoperative radiation therapy for various cancers in the head-and-neck region were prospectively evaluated. Patient serum samples (tri-iodothyronine, thyroxine, thyroid-stimulating hormone [TSH], free tri-iodothyronine, and free thyroxine) were measured before and at regular time intervals until 1 year after the completion of radiation therapy. Dose-volume histograms (DVHs) of the patients' thyroid gland were derived from their computed tomography (CT)-based treatment planning data. Hypothyroidism was defined as increased TSH (subclinical hypothyroidism) or increased TSH in combination with decreased free thyroxine and thyroxine (clinical hypothyroidism). Thyroid DVHs were converted to 2 Gy/fraction equivalent doses using the linear-quadratic formula with {alpha}/{beta} = 3 Gy. The evaluated models included the following: Lyman with the DVH reduced to the equivalent uniform dose (EUD), known as LEUD; Logit-EUD; mean dose; relative seriality; individual critical volume; and population critical volume models. The parameters of the models were obtained by fitting the patients' data using a maximum likelihood analysis method. The goodness of fit of the models was determined by the 2-sample Kolmogorov-Smirnov test. Ranking of the models was made according to Akaike's information criterion. Results: Twenty-nine patients (44.6%) experienced hypothyroidism. None of the models was rejected according to the evaluation of the goodness of fit. The mean dose model was ranked as the best model on the basis of its Akaike's information criterion value. The D{sub 50} estimated from the models was approximately 44 Gy. Conclusions: The implemented

Predicting Online Purchasing Behavior

OpenAIRE

W.R BUCKINX; D. VAN DEN POEL

2003-01-01

This empirical study investigates the contribution of different types of predictors to the purchasing behaviour at an online store. We use logit modelling to predict whether or not a purchase is made during the next visit to the website using both forward and backward variable-selection techniques, as well as Furnival and Wilson’s global score search algorithm to find the best subset of predictors. We contribute to the literature by using variables from four different categories in predicting...

Should we pay, and to whom, for biodiversity enhancement in private forests? An empirical study of attitudes towards payments for forest ecosystem services in Poland

OpenAIRE

Anna Bartczak; Katarzyna Metelska-Szaniawska

2015-01-01

This paper investigates the possibility of forest policy changes in Poland. The main objective is to investigate whether, and to whom, the society would be willing to pay for providing biodiversity enhancement in private forests. The empirical evidence is derived from a stated preference survey conducted on the national level and analyzed using a multinomial logit model (MNL). Our findings show a rather strong potential for the implementation of payments for ecosystem services (PES) in privat...

Manipulating a stated choice experiment

DEFF Research Database (Denmark)

Fosgerau, Mogens; Borjesson, Maria

2015-01-01

This paper considers the design of a stated choice experiment intended to measure the marginal rate of substitution (MRS) between cost and an attribute such as time using a conventional logit model. Focusing the experimental design on some target MRS will bias estimates towards that value....... The paper shows why this happens. The resulting estimated MRS can then be manipulated by adapting the target MRS in the experimental design. (C) 2015 Elsevier Ltd. All rights reserved....

Network Competition and Entry Deterrence

OpenAIRE

Calzada, Joan; Valletti, Tommaso

2005-01-01

We develop a model of logit demand that extends to a multi-firm industry the traditional duopoly framework of network competition with access charges. Firstly, we show that, when incumbents do not face the threat of entry and compete in prices, they inefficiently establish the reciprocal access charge below cost. This inefficiency disappears if incumbents compete in utilities instead of prices. Secondly, we study how incumbents change their choices under the threat of entry when they determin...

The impact of the residential built environment on work at home adoption frequency: An example from Northern California

OpenAIRE

Tang, Wei (Laura); Mokhtarian, Patricia L.; Handy, Susan L.

2011-01-01

Working at home is widely viewed as a useful travel-reduction strategy, and it is partly for that reason that considerable research related to telecommuting and home-based work has been conducted in the last two decades. This study examines the effect of residential neighborhood built environment (BE) factors on working at home. After systematically presenting and categorizing various relevant elements of the BE and reviewing related studies, we develop a multinomial logit (MNL) model of work...

Efektivita predikčních trhů: případ Intradu

OpenAIRE

Brandejs, David

2013-01-01

1 Abstract Bachelor thesis confirms weak market efficiency hypothesis for political events, which took place on Intrade prediction market and finished between 1. October and 31. December 2012. Three unit root tests, ADF GLS, KPSS and Lo-Mackinlay test proved on 5% confidence level, that 140 of 191 tested political events is weakly market efficient, which means high relative market efficiency (73,3%). Testing out-of-political markets shows significantly lower market efficiency. Logit model rej...

Livelihood strategies, environmental dependency and rural poverty

DEFF Research Database (Denmark)

Walelign, Solomon Zena

2016-01-01

This article attempts to explore the nexus between rural households’ environmental dependency, poverty and livelihood strategies. Households’ income from each livelihood activities formed the basis for categorizing households according to livelihood strategies. The principal component analysis...... of livelihood choice were analyzed using multinomial logit model. The results indicate the existence of marked differences in environmental dependency, rural poverty and asset endowments across the livelihood groups. Household’s total saving, access to credit, production implements, business cost, exposure...

Local and/or organic: A study on consumer preferences for organic food and food from different origins

OpenAIRE

Feldmann , Corinna; Hamm, Ulrich

2014-01-01

The purpose of this paper is to get a deeper insight into consumer preferences for different food products varying in their places of origin (i.e. local, Germany, neighbouring country, non-EU country) and production practices (i.e. organic vs. non-organic). Therefore, consumer surveys combined with choice experiments were conducted with 641 consumers in eight supermarkets in different parts of Germany. Multinomial and mixed logit models were estimated to draw conclusions on the preference str...

Employment Composition: A Study of Australian Employment Growth, 2002–2006

OpenAIRE

Jeremy Lawson; Crystal Ossolinski

2010-01-01

This paper uses data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey to examine whether there was a change in employment rates for people with ‘low employment’ characteristics between 2002 and 2006, which was a period of strong employment growth. In particular, it estimates the relationships between employment and personal and household characteristics using a binomial logit model, with a comparison of the coefficients in 2002 and 2006 providing tentative evidence o...

SNAP Participants? Eating Patterns over the Benefit Month: A Time Use Perspective

OpenAIRE

Hamrick, Karen S.; Andrews, Margaret

2016-01-01

Individuals receiving monthly benefits through the U.S. Supplemental Nutrition Assistance Program (SNAP) often fall short of food at the end of the month and some report feelings of hunger. To investigate this situation, we used time diaries from the 2006-08 American Time Use Survey and Eating & Health Module to identify the timing of days where respondents reported no eating occurrences. Analysis includes descriptive statistics, a logit model, and a simulated benefit month. We found that SNA...

CORN PRODUCERS´ RESPONSE TO THE 2001 NITROGEN FERTILIZER PRICE INCREASE

OpenAIRE

Daberkow, Stan G.; McBride, William D.

2004-01-01

During the past few years, nitrogen fertilizer prices and price volatility have increased. Producers of nitrogen-intensive crops, such as corn, who are faced with increased nitrogen prices or price volatility, can adopt either cost-reducing or price variability-reducing strategies. Using a behavioral model in the logit specification and data from a 2001 national survey of U.S. corn producers, we found that the probability of forward pricing nitrogen fertilizer and the probability of using nit...

New Evidence on Measuring Financial Constraints: Moving Beyond the KZ Index

OpenAIRE

Charles J. Hadlock; Joshua R. Pierce

2010-01-01

We collect detailed qualitative information from financial filings to categorize financial constraints for a random sample of firms from 1995 to 2004. Using this categorization, we estimate ordered logit models predicting constraints as a function of different quantitative factors. Our findings cast serious doubt on the validity of the KZ index as a measure of financial constraints, while offering mixed evidence on the validity of other common measures of constraints. We find that firm size a...

Tingkat Kesetaraan Gender Ingkat Kesetaraan Gender Pada Industri Kulit Di Propinsi Daerah Istimewa Yogayakarta

OpenAIRE

Priyadi, Unggul; Astuti, Budi

2009-01-01

Leather industry is one of small industries in Special Yogyakarta Province which contributes Regional Gross Domestic Product (PDRB) and generates employment. This re¬search analyzes cross section data in 2000th using purposive sampling method for data col¬lecting. Data analysis is Gender Inequality and Equivalent Index (IKKG) and Logit Model. Based on the empirical analysis, conclusions of this research are: 1) IKKG of entrepreneur leathers who have Educational Elementary School (SD), SMP, an...

Analyzing the Effects of Car Sharing Services on the Reduction of Greenhouse Gas (GHG Emissions

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Jiyeon Jung

2018-02-01

Full Text Available This study examines the environmental impacts of roundtrip car sharing services by investigating transportation behavior. Car sharing should contribute to reduced greenhouse gas GHG emissions; however, such schemes include both positive and negative environmental effects, including: (1 reduced CO2e (carbon dioxide equivalent from substituting private vehicle use for more fuel-efficient car sharing vehicles, (2 increased CO2e as car-less individuals switch from public transit to car sharing vehicles and (3 reduced CO2e due to fewer vehicles. This study examines the impacts of this modal shift on greenhouse gas (GHG emissions using three types of models: a mixed logit model to analyze car sharing service preferences; a binary logit model to analyze whether individuals are willing to forgo vehicle ownership or planned purchases to use car sharing services; and a linear regression to determine how much private vehicle or public transportation use would be replaced by car sharing and the resulting effects on mobility. Total emissions from the current car sharing market equal 1,025,589.36 t CO2e/year. However, an increase in electric vehicle (EV charging stations to 50% of the number of gasoline-fuel stations would increase the probability of electric car sharing vehicle use, thereby reducing emissions by 655,773 t CO2e. This study shows that forgoing vehicle purchases does not offset the increased GHG emissions caused by the shift from public transportation or private vehicle use to car sharing.

Summary goodness-of-fit statistics for binary generalized linear models with noncanonical link functions.

Science.gov (United States)

Canary, Jana D; Blizzard, Leigh; Barry, Ronald P; Hosmer, David W; Quinn, Stephen J

2016-05-01

Generalized linear models (GLM) with a canonical logit link function are the primary modeling technique used to relate a binary outcome to predictor variables. However, noncanonical links can offer more flexibility, producing convenient analytical quantities (e.g., probit GLMs in toxicology) and desired measures of effect (e.g., relative risk from log GLMs). Many summary goodness-of-fit (GOF) statistics exist for logistic GLM. Their properties make the development of GOF statistics relatively straightforward, but it can be more difficult under noncanonical links. Although GOF tests for logistic GLM with continuous covariates (GLMCC) have been applied to GLMCCs with log links, we know of no GOF tests in the literature specifically developed for GLMCCs that can be applied regardless of link function chosen. We generalize the Tsiatis GOF statistic originally developed for logistic GLMCCs, (TG), so that it can be applied under any link function. Further, we show that the algebraically related Hosmer-Lemeshow (HL) and Pigeon-Heyse (J(2) ) statistics can be applied directly. In a simulation study, TG, HL, and J(2) were used to evaluate the fit of probit, log-log, complementary log-log, and log models, all calculated with a common grouping method. The TG statistic consistently maintained Type I error rates, while those of HL and J(2) were often lower than expected if terms with little influence were included. Generally, the statistics had similar power to detect an incorrect model. An exception occurred when a log GLMCC was incorrectly fit to data generated from a logistic GLMCC. In this case, TG had more power than HL or J(2) . © 2015 John Wiley & Sons Ltd/London School of Economics.

Values for the ICECAP-Supportive Care Measure (ICECAP-SCM) for use in economic evaluation at end of life.

Science.gov (United States)

Huynh, Elisabeth; Coast, Joanna; Rose, John; Kinghorn, Philip; Flynn, Terry

2017-09-01

End of life care may have elements of value that go beyond health. A generic measure of the benefits of end of life care could be helpful to decision makers. Such a measure, based on the capability approach, has recently been developed: the ICECAP Supportive Care Measure. This paper reports the first valuation exercise for that measure, with data from 6020 individuals collected from an on-line general population panel during June 2013. Individuals were asked to complete a stated choice experiment that combined best-worst scaling and a standard discrete choice experiment. Analysis of the best-worst data used limited dependent variable models within the random utility framework including the multinomial logit models and latent class choice model analysis. Exploratory steps were taken to determine the similarity of the best-worst and DCE data before formal testing and pooling of the two data sources. Combined data were analysed in a heteroscedastic conditional logit model adjusting for continuous scale. Two sets of tariffs were generated, one from the best-worst data capturing only main effects, and a second from the pooled data allowing for two-way interactions. Either tariff could be used in economic evaluation of interventions at the end of life, although there are advantages and disadvantages with each. This extensive valuation exercise for the ICECAP Supportive Care Measure, with a large number of members of the general public, could be complemented in the future with best-worst scaling studies amongst those experiencing the end of life. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Acceptance of yoghurt with different functional ingredients among consumers in supermarkets in southern Chile].

Science.gov (United States)

Schnettler, Berta; Shene, Carolina; Rubilar, Mónica; Miranda, Horacio; Sepúlveda, José; Denegri, Marianela; Lobos, Germán

2010-12-01

In view of the interest in the role of foodstuffs in improving wellbeing and health, the object of this study is to distinguish consumer typologies in Temuco, La Araucanía Region, Chile, according to their preferences for different functional ingredients, flavouring, colouring and price in yoghurt. A semi-structured survey was applied to 400 supermarket customers. The respondents ordered eight alternative yoghurts according to their preferences, with different functional ingredients (fibre, antioxidants), flavourings (sugar, sweetener), colouring (natural, artificial) and three price options, for a conjoint analysis with fractional factorial design. Variables affecting knowledge of "functional food" were evaluated using a binomial logit model. It was determined by conjoint analysis that in general a preference existed for yoghurt containing fibre, sweetener, natural colouring, and at the lowest price. Three typologies were distinguished by analysis of hierarchical conglomerates: the majority segment (48.8%) displayed a greater preference for fibre; the second (41.7%) also preferred fibre, but gave first priority to artificial colouring and preferred a higher price. The minority (9.5%) was the only segment to prefer antioxidants. The typologies differed significantly in satisfaction with their food-related life, knowledge of the function of fibre and presence of cancer and obesity in some member of the respondent's family. The binomial logit model was significant (P acceptance of yoghurt enriched with fibre and with added sweetener.

How flexible is flexible? Accounting for the effect of rescheduling possibilities in choice of departure time for work trips

DEFF Research Database (Denmark)

Thorhauge, Mikkel; Cherchi, Elisabetta; Rich, Jeppe

2016-01-01

for each of these activities. We then built a stated preference experiment to infer preferences on departure time choice, and estimated a mixed logit model, based on the scheduling model, to account for the effects of daily activity schedules and their constraints. Our results show that measuring......In departure time studies it is crucial to ascertain whether or not individuals are flexible in their choices. Previous studies have found that individuals with flexible work times have a lower value of time for late arrivals. Flexibility is usually measured in terms of flexible work start time...... is not accounted for....

Price vector effects in choice experiments: an empirical test

International Nuclear Information System (INIS)

Hanley, Nick; Wright, Robert E.; Adamowicz, Wiktor

2005-01-01

This paper investigates whether the preference and willingness-to-pay estimates obtained from the choice experiment method of estimating non-market values are sensitive to the vector of prices used in the experimental design. We undertake this test in the context of water quality improvements under the European Union's new Water Framework Directive. Using a mixed logit model, which allows for differing scale between the two samples, we find no significant impact of changing the price vector on estimates of preferences or willingness-to-pay. (author) (Choice modelling; Non-market valuation; Design effects; Water Framework Directive)

Effectiveness of the Costa Rican Central Bank forex intervention

Directory of Open Access Journals (Sweden)

Julio César Espinoza Rodríguez

2016-03-01

Full Text Available This paper represents an empirical approach to assess the effectiveness of foreign exchange interventions following the criteria by K. Domínguez (1998 using a GARCH model based on the work by C. Broto (2012. Analyses are conducted to evaluate the FOREX rules of intervention followed by the BCCR, and the probability of occurrence of an intervention is estimated using a LOGIT model.  In addition, the paper attempts to analyze what happened to the exchange arrangements applied in Costa Rica as a result of the 2006 exchange rate flexibility and transition to inflation targets.

Predicting Spatial Distribution of Key Honeybee Pests in Kenya Using Remotely Sensed and Bioclimatic Variables: Key Honeybee Pests Distribution Models

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David M. Makori

2017-02-01

Full Text Available Bee keeping is indispensable to global food production. It is an alternate income source, especially in rural underdeveloped African settlements, and an important forest conservation incentive. However, dwindling honeybee colonies around the world are attributed to pests and diseases whose spatial distribution and influences are not well established. In this study, we used remotely sensed data to improve the reliability of pest ecological niche (EN models to attain reliable pest distribution maps. Occurrence data on four pests (Aethina tumida, Galleria mellonella, Oplostomus haroldi and Varroa destructor were collected from apiaries within four main agro-ecological regions responsible for over 80% of Kenya’s bee keeping. Africlim bioclimatic and derived normalized difference vegetation index (NDVI variables were used to model their ecological niches using Maximum Entropy (MaxEnt. Combined precipitation variables had a high positive logit influence on all remotely sensed and biotic models’ performance. Remotely sensed vegetation variables had a substantial effect on the model, contributing up to 40.8% for G. mellonella and regions with high rainfall seasonality were predicted to be high-risk areas. Projections (to 2055 indicated that, with the current climate change trend, these regions will experience increased honeybee pest risk. We conclude that honeybee pests could be modelled using bioclimatic data and remotely sensed variables in MaxEnt. Although the bioclimatic data were most relevant in all model results, incorporating vegetation seasonality variables to improve mapping the ‘actual’ habitat of key honeybee pests and to identify risk and containment zones needs to be further investigated.

Modeling crash injury severity by road feature to improve safety.

Science.gov (United States)

Penmetsa, Praveena; Pulugurtha, Srinivas S

2018-01-02

The objective of this research is 2-fold: to (a) model and identify critical road features (or locations) based on crash injury severity and compare it with crash frequency and (b) model and identify drivers who are more likely to contribute to crashes by road feature. Crash data from 2011 to 2013 were obtained from the Highway Safety Information System (HSIS) for the state of North Carolina. Twenty-three different road features were considered, analyzed, and compared with each other as well as no road feature. A multinomial logit (MNL) model was developed and odds ratios were estimated to investigate the effect of road features on crash injury severity. Among the many road features, underpass, end or beginning of a divided highway, and on-ramp terminal on crossroad are the top 3 critical road features. Intersection crashes are frequent but are not highly likely to result in severe injuries compared to critical road features. Roundabouts are least likely to result in both severe and moderate injuries. Female drivers are more likely to be involved in crashes at intersections (4-way and T) compared to male drivers. Adult drivers are more likely to be involved in crashes at underpasses. Older drivers are 1.6 times more likely to be involved in a crash at the end or beginning of a divided highway. The findings from this research help to identify critical road features that need to be given priority. As an example, additional advanced warning signs and providing enlarged or highly retroreflective signs that grab the attention of older drivers may help in making locations such as end or beginning of a divided highway much safer. Educating drivers about the necessary skill sets required at critical road features in addition to engineering solutions may further help them adopt safe driving behaviors on the road.

Modeling metro users' travel behavior in Tehran: Frequency of Use

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Amir Reza Mamdoohi

2016-10-01

Full Text Available Transit-oriented development (TOD, as a sustainable supporting strategy, emphasizes the improvement of public transportation coverage and quality, land use density and diversity of around public transportation stations and priority of walking and cycling at station areas. Traffic, environmental and economic problems arising from high growth of personal car, inappropriate distribution of land use, and car-orientation of metropolitan area, necessitate adoption of TOD. In recent years, more researches on urban development and transportation have focused on this strategy. This research considering metro stations as base for development, aims to model metro users' travel behavior and decision-making procedures. In this regard, research question is: what are the parameters or factors affecting in the frequency of travel by metro in half-mile radius from stations. The radius was determine based on TOD definitions and 5 minute walking time to metro stations.  A questionnaire was designed in three sections that including travel features by metro, attitudes toward metro, economic and social characteristics of respondents. Ten stations were selected based on their geographic dispersion in Tehran and a sample of 450 respondents was determined. The questionnaires were surveyed face to face in (half-mile vicinity of metro stations. Based on a refined sample on 400 questionnaires ordered discrete choice models were considered. Results of descriptive statistics show that 38.5 percent of the sample used metro more than 4 times per week. Trip purpose for 45.7 percent of metro users is work. Access mode to the metro stations for nearly half of the users (47.6 percent is bus. Results of ordered logit models show a number of significant variables including: habit of using the metro, waiting time in station, trip purpose (working, shopping and recreation, personal car access mode to the metro station, walking access mode to the metro station and being a housewife.

Discrete Choice Model of Food Store Trips Using National Household Food Acquisition and Purchase Survey (FoodAPS).

Science.gov (United States)

Hillier, Amy; Smith, Tony E; Whiteman, Eliza D; Chrisinger, Benjamin W

2017-09-27

Where households across income levels shop for food is of central concern within a growing body of research focused on where people live relative to where they shop, what they purchase and eat, and how those choices influence the risk of obesity and chronic disease. We analyzed data from the National Household Food Acquisition and Purchase Survey (FoodAPS) using a conditional logit model to determine where participants shop for food to be prepared and eaten at home and how individual and household characteristics of food shoppers interact with store characteristics and distance from home in determining store choice. Store size, whether or not it was a full-service supermarket, and the driving distance from home to the store constituted the three significant main effects on store choice. Overall, participants were more likely to choose larger stores, conventional supermarkets rather than super-centers and other types of stores, and stores closer to home. Interaction effects show that participants receiving Supplemental Nutrition Assistance Program (SNAP) were even more likely to choose larger stores. Hispanic participants were more likely than non-Hispanics to choose full-service supermarkets while White participants were more likely to travel further than non-Whites. This study demonstrates the value of explicitly spatial discrete choice models and provides evidence of national trends consistent with previous smaller, local studies.

Discrete Choice Model of Food Store Trips Using National Household Food Acquisition and Purchase Survey (FoodAPS

Directory of Open Access Journals (Sweden)

Amy Hillier

2017-09-01

Full Text Available Where households across income levels shop for food is of central concern within a growing body of research focused on where people live relative to where they shop, what they purchase and eat, and how those choices influence the risk of obesity and chronic disease. We analyzed data from the National Household Food Acquisition and Purchase Survey (FoodAPS using a conditional logit model to determine where participants shop for food to be prepared and eaten at home and how individual and household characteristics of food shoppers interact with store characteristics and distance from home in determining store choice. Store size, whether or not it was a full-service supermarket, and the driving distance from home to the store constituted the three significant main effects on store choice. Overall, participants were more likely to choose larger stores, conventional supermarkets rather than super-centers and other types of stores, and stores closer to home. Interaction effects show that participants receiving Supplemental Nutrition Assistance Program (SNAP were even more likely to choose larger stores. Hispanic participants were more likely than non-Hispanics to choose full-service supermarkets while White participants were more likely to travel further than non-Whites. This study demonstrates the value of explicitly spatial discrete choice models and provides evidence of national trends consistent with previous smaller, local studies.

Comparison of the psychometric properties of two balance scales in children with cerebral palsy.

Science.gov (United States)

Jeon, Yong-Jin; Kim, Gyoung-Mo

2016-12-01

[Purpose] The purpose of this study was to compare the item difficulty degree between the Pediatric Balance Scale and Fullerton Advanced Balance scale for children with cerebral palsy. [Subjects and Methods] Forty children with cerebral palsy (male=17, female=23) voluntarily participated in the study. Item difficulty was expressed in the Rasch analysis using a logit value, with a higher value indicative of increasing item difficulty. [Results] Among the 24 items of the combined Pediatric Balance Scale and Fullerton Advanced Balance scale, the most difficult item was "Walk with head turns", whereas, the easiest item was "Sitting with back unsupported and feet supported on the floor". Among the 14 items of the Pediatric Balance Scale, 9 items (item 1, 2, 3, 4, 5, 6, 7, 11, and 12) had negative logit values, whereas for the Fullerton Advanced Balance scale, only 1 item (item 1) had a negative logit value. [Conclusion] The Fullerton Advanced Balance scale is a more appropriate tool to assess balance ability than the Pediatric Balance Scale in in a group of higher functioning children with cerebral palsy.

Household's willingness to pay for heterogeneous attributes of drinking water quality and services improvement: an application of choice experiment

Science.gov (United States)

Dauda, Suleiman Alhaji; Yacob, Mohd Rusli; Radam, Alias

2015-09-01

The service of providing good quality of drinking water can greatly improve the lives of the community and maintain a normal health standard. For a large number of population in the world, specifically in the developing countries, the availability of safe water for daily sustenance is none. Damaturu is the capital of Yobe State, Nigeria. It hosts a population of more than two hundred thousand, yet only 45 % of the households are connected to the network of Yobe State Water Corporation's pipe borne water services; this has led people to source for water from any available source and thus, exposed them to the danger of contracting waterborne diseases. In order to address the problem, Yobe State Government has embarked on the construction of a water treatment plant with a capacity and facility to improve the water quality and connect the town with water services network. The objectives of this study are to assess the households' demand preferences of the heterogeneous water attributes in Damaturu, and to estimate their marginal willingness to pay, using mixed logit model in comparison with conditional logit model. A survey of 300 households randomly sampled indicated that higher education greatly influenced the households' WTP decisions. The most significant variable from both of the models is TWQ, which is MRS that rates the water quality from the level of satisfactory to very good. 219 % in simple model is CLM, while 126 % is for the interaction model. As for MLM, 685 % is for the simple model and 572 % is for the interaction model. Estimate of MLM has more explanatory powers than CLM. Essentially, this finding can help the government in designing cost-effective management and efficient tariff structure.

The Influences of Health Insurance and Access to Information on Prostate Cancer Screening among Men in Dominican Republic

International Nuclear Information System (INIS)

Kangmennaang, J.; Luginaah, I.

2016-01-01

Although research demonstrates the public health burden of prostate cancer among men in the Caribbean, relatively little is known about the factors that underlie the low levels of testing for the disease among this population. Study Design. A cross-sectional study of prostate cancer testing behaviours among men aged 40-60 years in Dominican Republic using the Demographic and Health Survey (2013). Methods. We use hierarchical binary logit regression models and average treatment effects combined with propensity score matching to explore the determinants of prostate screening as well as the average effect of health insurance coverage on screening. The use of hierarchical binary logit regression enabled us to control for the effect of unobserved heterogeneity at the cluster level that may affect prostate cancer testing behaviours. Results. Screening varied significantly with health insurance coverage, knowledge of cholesterol level, education, and wealth. Insured men were more likely to test for prostate cancer (OR=1.65, P=0.01) compared to the uninsured. Conclusions. The expansion and restructuring of Dominican Republic universal health insurance scheme to ensure equity in access may improve health access that would potentially impact positively on prostate cancer screening among men.

Renewable energy adoption in an ageing population: Heterogeneity in preferences for micro-generation technology adoption

Energy Technology Data Exchange (ETDEWEB)

Willis, Ken, E-mail: Ken.Willis@ncl.ac.uk [School of Architecture, Planning and Landscape, University of Newcastle, Newcastle upon Tyne NE1 7RU (United Kingdom); Scarpa, Riccardo [Department of Economics, Waikato School of Management, University of Waikato, Hamilton (New Zealand); Gilroy, Rose; Hamza, Neveen [School of Architecture, Planning and Landscape, University of Newcastle, Newcastle upon Tyne NE1 7RU (United Kingdom)

2011-10-15

Many countries are endeavouring to supply more of their energy from renewable resources. Such countries are also experiencing an aging population with a greater proportion of people aged {>=}65 years. This demographic shift may reduce the uptake of renewable energy, if older person households are less inclined to accept change and adopt new technologies. This paper assesses whether such households have different behavioural responses to energy efficiency compared to the rest of society and investigates whether micro-generation renewable energy technologies are less likely to be adopted by these households. It uses conditional logit and mixed logit models to investigate the impact of age of household on primary heating adoption, and also to assess the impact of older households on the installation of discretionary micro-generation technologies (solar thermal, solar voltaic, and wind power) to supplement existing heating and lighting systems. Results indicate that primary heating choice is not affected but that older person households are less inclined to adopt micro-generation technologies. - Highlights: > Heterogeneity exists in decisions on micro-generation technology installation. > Older person households are less inclined to adopt micro-generation technologies. > Micro-generation technologies fail a social cost-benefit analysis test.

Renewable energy adoption in an ageing population: Heterogeneity in preferences for micro-generation technology adoption

International Nuclear Information System (INIS)

Willis, Ken; Scarpa, Riccardo; Gilroy, Rose; Hamza, Neveen

2011-01-01

Many countries are endeavouring to supply more of their energy from renewable resources. Such countries are also experiencing an aging population with a greater proportion of people aged ≥65 years. This demographic shift may reduce the uptake of renewable energy, if older person households are less inclined to accept change and adopt new technologies. This paper assesses whether such households have different behavioural responses to energy efficiency compared to the rest of society and investigates whether micro-generation renewable energy technologies are less likely to be adopted by these households. It uses conditional logit and mixed logit models to investigate the impact of age of household on primary heating adoption, and also to assess the impact of older households on the installation of discretionary micro-generation technologies (solar thermal, solar voltaic, and wind power) to supplement existing heating and lighting systems. Results indicate that primary heating choice is not affected but that older person households are less inclined to adopt micro-generation technologies. - Highlights: → Heterogeneity exists in decisions on micro-generation technology installation. → Older person households are less inclined to adopt micro-generation technologies. → Micro-generation technologies fail a social cost-benefit analysis test.

Occupational segregation, selection effects and gender wage differences: evidence from urban Colombia

Directory of Open Access Journals (Sweden)

Jairo Guillermo Isaza Castro

2014-06-01

Full Text Available This paper assesses the effects of occupational segregation on the gender wage gap in urban Colombia between 1986 and 2000. The empirical methodology involves a two step procedure where by the occupational distributions ofworkers by gender aremodelled using a multinomial logit model in the first stage. In the second stage, the multinomial logit estimates are used not only to derive a counterfactual occupational distribution of women in the absence of workplace discrimination but also to correct for selectivity bias in thewage equations for each occupational category using the procedure suggested by Lee (1983. Besides the explained and unexplained components in conventional decompositions of the gender wage gap, this methodology differentiates between the justified and unjustified effects of the gender allocation ofworkers across occupational categories. The results for urban Colombia indicate that controlling for selectivity bias at the occupational category level is found to be relevant in all years reviewed in this study. They also suggest that a changing composition of the female labour supply in terms of un observables (i.e., ability and motivation is playing a role in the dramatic reduction of the observed wage gap.

Meta-analysis of prediction model performance across multiple studies: Which scale helps ensure between-study normality for the C-statistic and calibration measures?

Science.gov (United States)

Snell, Kym Ie; Ensor, Joie; Debray, Thomas Pa; Moons, Karel Gm; Riley, Richard D

2017-01-01

If individual participant data are available from multiple studies or clusters, then a prediction model can be externally validated multiple times. This allows the model's discrimination and calibration performance to be examined across different settings. Random-effects meta-analysis can then be used to quantify overall (average) performance and heterogeneity in performance. This typically assumes a normal distribution of 'true' performance across studies. We conducted a simulation study to examine this normality assumption for various performance measures relating to a logistic regression prediction model. We simulated data across multiple studies with varying degrees of variability in baseline risk or predictor effects and then evaluated the shape of the between-study distribution in the C-statistic, calibration slope, calibration-in-the-large, and E/O statistic, and possible transformations thereof. We found that a normal between-study distribution was usually reasonable for the calibration slope and calibration-in-the-large; however, the distributions of the C-statistic and E/O were often skewed across studies, particularly in settings with large variability in the predictor effects. Normality was vastly improved when using the logit transformation for the C-statistic and the log transformation for E/O, and therefore we recommend these scales to be used for meta-analysis. An illustrated example is given using a random-effects meta-analysis of the performance of QRISK2 across 25 general practices.

External Shocks and Banking Crises in Developing Countries: Does the Exchange Rate Regime Matter?

OpenAIRE

Chandima Mendis

2002-01-01

This paper examines some determinants of banking crises in developing economies. Specifically, the effects of terms of trade shocks and capital flows are analyzed. The choice of the nominal exchange rate regime is found to be a crucial factor in the way various shocks are transmitted through the monetary sector. A logit model is used on panel data and preliminary results indicate that countries with flexible regimes were able to lessen the impact of external shocks on the domestic economy. Th...

Transitions between states of labor-force participation among older Israelis

OpenAIRE

Achdut, Leah; Tur-Sinai, Aviad; Troitsky, Rita

2014-01-01

The study examines the labor-force behavior of Israelis at older ages, focusing on the determinants of the transitions between states of labor-force participation between 2005 and 2010. The study uses panel data from the first two waves of the SHARE-Israel longitudinal survey. A multinomial logit model is used to examine the impact of sociodemographic characteristics, health state, and economic resources on labor-force transitions of people aged 50–67. The results emphasize the role of age an...

Impact of Public Market Information System (PMIS) on Farmers Food Marketing Decisions: Case of Benin

OpenAIRE

Kpenavoun Chogou, Sylvain; Lebailly, Philippe; Adegbidi, Anselme; Gandonou, Esaie

2009-01-01

To sell their surpluses of maize, the main staple in Benin, farmers may choose among three modes of transaction: they may sell under a contract with itinerant traders, or they may sell without a contract at the farmgate or on distant markets. It has been postulated that farmers may choose a profitable mode of transaction if they have good access to information on the prevailing market conditions. Using detailed farm household survey data from Benin, this paper applies the Nested Logit model t...

The Role of Neighborhood Characteristics in the Adoption and Frequency of Working at Home: Empirical Evidence from Northern California

OpenAIRE

Tang, Wei; Mokhtarian, Patricia; Handy, Susan

2008-01-01

Working at home is widely viewed as a useful travel-reduction strategy, and partly for that reason, considerable research related to telecommuting and home-based work has been conducted in the last two decades. The contribution of this study is to examine the effect of residential neighborhood built environment (BE) factors on working at home. Using data from a survey of eight neighborhoods in Northern California, we develop a multinomial logit (MNL) model of work-at-home (WAH) frequency. Pot...

Two Notes on Discrimination and Decomposition

DEFF Research Database (Denmark)

Nielsen, Helena Skyt

1998-01-01

1. It turns out that the Oaxaca-Blinder wage decomposition is inadequate when it comes to calculation of separate contributions for indicator variables. The contributions are not robust against a change of reference group. I extend the Oaxaca-Blinder decomposition to handle this problem. 2. The p....... The paper suggests how to use the logit model to decompose the gender difference in the probability of an occurrence. The technique is illustrated by an analysis of discrimination in child labor in rural Zambia....

Effects of gender, education and health communication on the regularity of physical exercise: a 2016 Vietnamese cross-section survey

OpenAIRE

Vuong, Quan-Hoang; Pham, Hiep-Hung; Vuong, Thu Trang

2017-01-01

Nowadays, physical exercise and sports activities are regarded as the best means for people to keep fit and boost their health. In Vietnam, exercising on a daily basis is still underappreciated as twothirds of the population only exercise at trivial or low levels. Based on applying the baseline category logit model, we conduct an analysis to figure out the factors affecting people’s level of exercise. The findings show that males tend to engage in physical activities more than females, with t...

World-First Innovations in an Open Innovation Context

OpenAIRE

Hochleitner, Franciane Paz; Arbussà i Reixach, Anna; Coenders, Germà

2016-01-01

This study contributes to the current literature on open innovation by analysing the effects of open innovation activities on the introduction of new-to-the-world innovations versus imitation. We base our analysis on data provided by the Eurostat Community Innovation Survey (CIS) carried out in Germany in 2012, which for the first time made a distinction between world-first innovation and imitation. We use both logit models and CHAID trees. The results of both analyses show that traditional i...

Stated environmental preferences in a Romanian rural community

OpenAIRE

Toma, Luiza; Mathijs, Erik

2004-01-01

This article uses random utility theory to analyse the economic and environmental trade-offs at farm level in a Romanian rural area confronting water pollution on the basis of survey data. To underline the impact of socio-economic variables in the decision-making process at farm level as regards environmental choices, a binary logit model is estimated that includes socio-economic variables in addition to the attributes in the choice set. The study shows that heterogeneity in tastes is partial...

An Objective Screening Method for Major Depressive Disorder Using Logistic Regression Analysis of Heart Rate Variability Data Obtained in a Mental Task Paradigm

Directory of Open Access Journals (Sweden)

Guanghao Sun

2016-11-01

Full Text Available Background and Objectives: Heart rate variability (HRV has been intensively studied as a promising biological marker of major depressive disorder (MDD. Our previous study confirmed that autonomic activity and reactivity in depression revealed by HRV during rest and mental task (MT conditions can be used as diagnostic measures and in clinical evaluation. In this study, logistic regression analysis (LRA was utilized for the classification and prediction of MDD based on HRV data obtained in an MT paradigm.Methods: Power spectral analysis of HRV on R-R intervals before, during, and after an MT (random number generation was performed in 44 drug-naïve patients with MDD and 47 healthy control subjects at Department of Psychiatry in Shizuoka Saiseikai General Hospital. Logit scores of LRA determined by HRV indices and heart rates discriminated patients with MDD from healthy subjects. The high frequency (HF component of HRV and the ratio of the low frequency (LF component to the HF component (LF/HF correspond to parasympathetic and sympathovagal balance, respectively.Results: The LRA achieved a sensitivity and specificity of 80.0% and 79.0%, respectively, at an optimum cutoff logit score (0.28. Misclassifications occurred only when the logit score was close to the cutoff score. Logit scores also correlated significantly with subjective self-rating depression scale scores (p < 0.05.Conclusion: HRV indices recorded during a mental task may be an objective tool for screening patients with MDD in psychiatric practice. The proposed method appears promising for not only objective and rapid MDD screening, but also evaluation of its severity.

Application of economic models to estimate the acceptability of a vehicle congestion charge

Directory of Open Access Journals (Sweden)

José Carlos Jiménez Serpa

2017-07-01

Full Text Available Introduction: Through the study of the problems generated by vehicular traffic congestion during periods of maximum demand, the negative externality of congestion would be assessed using Multinomial Logit, Mixed and econometric models, and willingness to pay through a Pigouvian rate. Objective: In this article, we propose to implement a congestion charge to manage vehicular demand, through the application of declared preference gages and econometric models. Methodology: The study consists of the execution of 6 steps or stages: Background of the problem, Context of study, Methodological Foundations, Specification and estimation of the model, Estimation of the function average cost user and social marginal cost, Results obtained Discussion and report. Results: Analyzing the models obtained from the 2053 observations made through the declared preference surveys, it was observed that in order to discourage the use of the private car, a rate of COP 7000 per vehicle entering the congestion area or area should be charged, which would decrease the Use of Auto Particular in 68.7%, referring to this behavior we can say that the government policies that set the collection of the congestion charge is a policy that does not fit the perception of the users. Conclusions: This research identified the rate that reflects as closely as possible the marginal social cost and the generalized costs of each trip in terms of the impacts on the others. Now if we consider the marginal cost due to congestion, we have that the current demand is excessive, the users enjoy the benefit at a cost of $ 3,100COP, but impose to others a quota of $22,152COP. Finally, it is necessary to strengthen the legal basis with the regulation and creation of a National Vehicle Electronic Identification System, which will allow, in principle, charges for congestion.

Suicidality in schizophrenia spectrum disorders: the relationship to hallucinations and persecutory delusions.

Science.gov (United States)

Kjelby, E; Sinkeviciute, I; Gjestad, R; Kroken, R A; Løberg, E-M; Jørgensen, H A; Hugdahl, K; Johnsen, E

2015-10-01

Assessment of suicide risk is crucial in schizophrenia and results concerning risk contributed by hallucinations and persecutory delusions are inconsistent. We aimed to determine factors associated with suicidal ideation and plans at the time of acute admission in patients suffering from schizophrenia spectrum disorders. One hundred and twenty-four patients older than 18 years admitted to an acute psychiatric ward due to psychosis were consecutively included. Predictors of suicidal ideation and suicide plans at the time of admission were examined with multinominal logistic regression and structural equation modelling (SEM). The study design was pragmatic, thus entailing a clinically relevant representation. Depression Odds Ratio (OR) 12.9, Drug use OR 4.07, Hallucinations OR 2.55 and Negative symptoms OR 0.88 significantly predicted Suicidal ideation. Suspiciousness/ Persecution did not. Only Depression and Hallucinations significantly predicted Suicide plans. In the SEM-model Anxiety, Depression and Hopelessness connected Suspiciousness/Persecution, Hallucinations and Lack of insight with Suicidal ideation and Suicide plans. The study contributes to an increasing evidence base supporting an association between hallucinations and suicide risk. We want to emphasise the importance of treating depression and hallucinations in psychotic disorders, reducing hopelessness while working with insight and reducing drug abuse in order to lower suicide risk. ClinicalTrials.gov ID; URL: http://www.clinicaltrials.gov/NCT00932529. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Self-rated health, multimorbidity and depression in Mexican older adults: Proposal and evaluation of a simple conceptual model.

Science.gov (United States)

Bustos-Vázquez, Eduardo; Fernández-Niño, Julián Alfredo; Astudillo-Garcia, Claudia Iveth

2017-04-01

Self-rated health is an individual and subjective conceptualization involving the intersection of biological, social and psychological factors. It provides an invaluable and unique evaluation of a person's general health status. To propose and evaluate a simple conceptual model to understand self-rated health and its relationship to multimorbidity, disability and depressive symptoms in Mexican older adults. We conducted a cross-sectional study based on a national representative sample of 8,874 adults of 60 years of age and older. Self-perception of a positive health status was determined according to a Likert-type scale based on the question: "What do you think is your current health status?" Intermediate variables included multimorbidity, disability and depressive symptoms, as well as dichotomous exogenous variables (sex, having a partner, participation in decision-making and poverty). The proposed conceptual model was validated using a general structural equation model with a logit link function for positive self-rated health. A direct association was found between multimorbidity and positive self-rated health (OR=0.48; 95% CI: 0.42-0.55), disability and positive self-rated health (OR=0.35; 95% CI: 0.30-0.40), depressive symptoms and positive self-rated health (OR=0.38; 95% CI: 0.34-0.43). The model also validated indirect associations between disability and depressive symptoms (OR=2.25; 95% CI: 2.01- 2.52), multimorbidity and depressive symptoms (OR=1.79; 95% CI: 1.61-2.00) and multimorbidity and disability (OR=1.98; 95% CI: 1.78-2.20). A parsimonious theoretical model was empirically evaluated, which enabled identifying direct and indirect associations with positive self-rated health.

Determinantes de la pérdida esperada en la cartera de clientes de una Institución Prestadora de Servicios de Salud

OpenAIRE

Correa Barragán, Carlos Julio

2016-01-01

La estimación de la pérdida esperada en las cuentas por cobrar de una empresa y la modelación de las variables que la determinan constituyen una importante herramienta de medición de riesgo, con efecto directo en el desempeño del patrimonio -- En este trabajo se realiza la estimación mediante un modelo econométrico logit para datos agrupados, en una institución prestadora de servicios de salud ubicada en Colombia -- Se presenta una selección de cuatro modelos basados en la metodología logit p...

Log Linear Models for Religious and Social Factors affecting the practice of Family Planning Methods in Lahore, Pakistan

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Farooq Ahmad

2006-01-01

Full Text Available This is cross sectional study based on 304 households (couples with wives age less than 48 years, chosen from urban locality (city Lahore. Fourteen religious, demographic and socio-economic factors of categorical nature like husband education, wife education, husband’s monthly income, occupation of husband, household size, husband-wife discussion, number of living children, desire for more children, duration of marriage, present age of wife, age of wife at marriage, offering of prayers, political view, and religiously decisions were taken to understand acceptance of family planning. Multivariate log-linear analysis was applied to identify association pattern and interrelationship among factors. The logit model was applied to explore the relationship between predictor factors and dependent factor, and to explore which are the factors upon which acceptance of family planning is highly depending. Log-linear analysis demonstrate that preference of contraceptive use was found to be consistently associated with factors Husband-Wife discussion, Desire for more children, No. of children, Political view and Duration of married life. While Husband’s monthly income, Occupation of husband, Age of wife at marriage and Offering of prayers resulted in no statistical explanation of adoption of family planning methods.

Exacerbations of COPD: quantifying the patient's perspective using discrete choice modelling.

Science.gov (United States)

Haughney, J; Partridge, M R; Vogelmeier, C; Larsson, T; Kessler, R; Ståhl, E; Brice, R; Löfdahl, C-G

2005-10-01

Patient-centred care is the current vogue in chronic obstructive pulmonary disease (COPD), but it is only recently that robust techniques have become available to determine patients' values and preferences. In this international cross-sectional study, patients' concerns and expectations regarding COPD exacerbations were explored using discrete choice modelling. A fractional factorial design was used to develop scenarios comprising a combination of levels for nine different attributes. In face-to-face interviews, patients were presented with paired scenarios and asked to choose the least preferable. Multinomial logit (with hierarchical Bayes) methods were used to estimate utilities. A total of 125 patients (82 males; mean age 66 yrs; 4.6 mean exacerbations.yr-1) were recruited. The attributes of exacerbations considered most important were impact on everyday life (20%), need for medical care (16%), number of future attacks (12%) and breathlessness (11%). The next most important attributes were speed of recovery, productive cough and social impact (all 9%), followed by sleep disturbance and impact on mood (both 7%). Importantly, analysis of utility shifts showed that patients most feared being hospitalised, housebound or bedridden. These issues were more important than symptom improvement. Strategies for the clinical management of chronic obstructive pulmonary disease should clearly address patients' concerns and focus on preventing and treating exacerbations to avoid these feared outcomes.

Health care seeking patterns and determinants of out-of-pocket expenditure for malaria for the children under-five in Uganda.

Science.gov (United States)

Nabyonga Orem, Juliet; Mugisha, Frederick; Okui, Albert Peter; Musango, Laurent; Kirigia, Joses Muthuri

2013-05-31

The objectives of this study were to assess the patterns of treatment seeking behaviour for children under five with malaria; and to examine the statistical relationship between out-of-pocket expenditure (OOP) on malaria treatment for under-fives and source of treatment, place of residence, education and wealth characteristics of Uganda households. OOP expenditure on health care is now a development concern due to its negative effect on households' ability to finance consumption of other basic needs. The 2009 Uganda Malaria Indicator Survey was the source of data on treatment seeking behaviour for under-five children with malaria, and patterns and levels of OOP expenditure for malaria treatment. Binomial logit and Log-lin regression models were estimated. In logit model the dependent variable was a dummy (1=incurred some OOP, 0=none incurred) and independent variables were wealth quintiles, rural versus urban, place of treatment, education level, sub-region, and normal duty disruption. The dependent variable in Log-lin model was natural logarithm of OOP and the independent variables were the same as mentioned above. Five key descriptive analysis findings emerge. First, malaria is quite prevalent at 44.7% among children below the age of five. Second, a significant proportion seeks treatment (81.8%). Third, private providers are the preferred option for the under-fives for the treatment of malaria. Fourth, the majority pay about 70.9% for either consultation, medicines, transport or hospitalization but the biggest percent of those who pay, do so for medicines (54.0%). Fifth, hospitalization is the most expensive at an average expenditure of US$7.6 per child, even though only 2.9% of those that seek treatment are hospitalized.The binomial logit model slope coefficients for the variables richest wealth quintile, Private facility as first source of treatment, and sub-regions Central 2, East central, Mid-eastern, Mid-western, and Normal duties disrupted were positive and

Prediction of health effects of cross-border atmospheric pollutants using an aerosol forecast model.

Science.gov (United States)

Onishi, Kazunari; Sekiyama, Tsuyoshi Thomas; Nojima, Masanori; Kurosaki, Yasunori; Fujitani, Yusuke; Otani, Shinji; Maki, Takashi; Shinoda, Masato; Kurozawa, Youichi; Yamagata, Zentaro

2018-08-01

Health effects of cross-border air pollutants and Asian dust are of significant concern in Japan. Currently, models predicting the arrival of aerosols have not investigated the association between arrival predictions and health effects. We investigated the association between subjective health symptoms and unreleased aerosol data from the Model of Aerosol Species in the Global Atmosphere (MASINGAR) acquired from the Japan Meteorological Agency, with the objective of ascertaining if these data could be applied to predicting health effects. Subjective symptom scores were collected via self-administered questionnaires and, along with modeled surface aerosol concentration data, were used to conduct a risk evaluation using generalized estimating equations between October and November 2011. Altogether, 29 individuals provided 1670 responses. Spearman's correlation coefficients were determined for the relationship between the proportion of the participants reporting the maximum score of two or more for each symptom and the surface concentrations for each considered aerosol species calculated using MASINGAR; the coefficients showed significant intermediate correlations between surface sulfate aerosol concentration and respiratory, throat, and fever symptoms (R = 0.557, 0.454, and 0.470, respectively; p < 0.01). In the general estimation equation (logit link) analyses, a significant linear association of surface sulfate aerosol concentration, with an endpoint determined by reported respiratory symptom scores of two or more, was observed (P trend = 0.001, odds ratio [OR] of the highest quartile [Q4] vs. the lowest [Q1] = 5.31, 95% CI = 2.18 to 12.96), with adjustment for potential confounding. The surface sulfate aerosol concentration was also associated with throat and fever symptoms. In conclusion, our findings suggest that modeled data are potentially useful for predicting health risks of cross-border aerosol arrivals. Copyright © 2018 Elsevier Ltd

Choice probability generating functions

DEFF Research Database (Denmark)

Fosgerau, Mogens; McFadden, Daniel; Bierlaire, Michel

2010-01-01

This paper establishes that every random utility discrete choice model (RUM) has a representation that can be characterized by a choice-probability generating function (CPGF) with specific properties, and that every function with these specific properties is consistent with a RUM. The choice...... probabilities from the RUM are obtained from the gradient of the CPGF. Mixtures of RUM are characterized by logarithmic mixtures of their associated CPGF. The paper relates CPGF to multivariate extreme value distributions, and reviews and extends methods for constructing generating functions for applications....... The choice probabilities of any ARUM may be approximated by a cross-nested logit model. The results for ARUM are extended to competing risk survival models....

Memprediksi Financial Distress dengan Binary Logit Regression Perusahaan Telekomunikasi

OpenAIRE

antikasari, tiara widya; Djuminah, Djuminah

2017-01-01

In this globalization era, sub–sector telecommunication industry has rapid development as time goes by with the number of customers’ growth. However, its growth is not balanced with operational revenue development. Therefore, it is important to analyze the financial distress in telecommunication companies in order to avoid bankruptcy. This research aimed to investigate the effect of financial ratios to predict probability of financial distress. Financial ratios indicator used profitability ra...

MEMPREDIKSI FINANCIAL DISTRESS DENGAN BINARY LOGIT REGRESSION PERUSAHAAN TELEKOMUNIKASI

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Tiara Widya Antikasari

2017-04-01

Full Text Available In this globalization era, sub–sector telecommunication industry has rapid development as time goes by with the number of customers’ growth. However, its growth is not balanced with operational revenue development. Therefore, it is important to analyze the financial distress in telecommunication companies in order to avoid bankruptcy. This research aimed to investigate the effect of financial ratios to predict probability of financial distress. Financial ratios indicator used profitability ratio, liquidity ratio, activity ratio, and leverage ratio. The population in this research was telecommunication companies listed in the Indonesia Stock Exchange periods 2009-2016. Based on purposive sampling method, the criteria of financial distress in this study was measured by using net operation negative two years, while statistic analysis used was logistic regression with a significance level of 10%. The result was that liquidity ratio (current ratio and activity ratio (total asset turnover ratio had a negative significant value, and profitability ratio(return on asset and leverage ratio (debt to total asset had positive significant value to predict financial distress.

Logit dynamics for strategic games mixing time and metastability

OpenAIRE

Ferraioli, Diodato

2012-01-01

2010 - 2011 A complex system is generally de_ned as a system emerging from the interaction of several and di_erent components, each one with their properties and their goals, usually subject to external inuences. Nowadays, complex systems are ubiquitous and they are found in many research areas: examples can be found in Economy (e.g., markets), Physics (e.g., ideal gases, spin systems), Biology (e.g., evolution of life) and Computer Science (e.g., Internet and social network...

Are formalised implementation activities associated with aspects of quality of care in general practice?

DEFF Research Database (Denmark)

Videbæk Le, Jette; Pedersen, Line Bjørnskov; Riisgaard, Helle

2017-01-01

questionnaire was distributed to GPs, and data on spirometry testing among first-time users of medication against obstructive lung diseases were obtained from national registers. Associations were investigated using multilevel mixed-effect logit models. Results GPs from 1,114 practices (58%) responded, and 33......-handed practices as in partnerships. Conclusion This study provides valuable knowledge for GPs who aim to organise their practice in a way that supports implementation and quality improvement most effectively. Also, results might be useful for managers of implementation strategies and quality improvement...

Adoption of health information technologies by physicians for clinical practice

DEFF Research Database (Denmark)

Villalba-Mora, Elena; Casas, Isabel; Lupiañez-Villanueva, Francisco

2015-01-01

OBJECTIVES: We investigated the level of adoption of Health Information Technologies (HIT) services, and the factors that influence this, amongst specialised and primary care physicians; in Andalusia, Spain. METHODS: We analysed the physicians' responses to an online survey. First, we performed...... Technologies: Electronic Health Records (EHR), ePrescription and patient management and telemedicine services. Results from an ordered logit model showed that the frequency of use of HIT is associated with the physicians' perceived usefulness. Lack of financing appeared as a common barrier to the adoption...

Decennial Life Tables for the White Population of the United States, 1790-1900.

Science.gov (United States)

Hacker, J David

2010-04-01

This article constructs new life tables for the white population of the United States in each decade between 1790 and 1900. Drawing from several recent studies, it suggests best estimates of life expectancy at age 20 for each decade. These estimates are fitted to new standards derived from the 1900-02 rural and 1900-02 overall DRA life tables using a two-parameter logit model with fixed slope. The resulting decennial life tables more accurately represent sex-and age-specific mortality rates while capturing known mortality trends.

Modeling Lane-Changing Behavior in Freeway Off-Ramp Areas from the Shanghai Naturalistic Driving Study

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Lanfang Zhang

2018-01-01

Full Text Available The objective of this study is to investigate lane-changing characteristics in freeway off-ramp areas using Shanghai Naturalistic Driving Study (SH-NDS data, considering a four-lane freeway stretch in various traffic conditions. In SH-NDS, the behavior of drivers is observed unobtrusively in a natural setting for a long period of time. We identified 433 lane-changing events with valid time series data from the whole dataset. Based on the logit model developed to analyze the choice of target lanes, a likelihood analysis of lane-changing behavior was graphed with respect to three traffic conditions: free flow, medium flow, and heavy flow. The results suggested that lane-changing behavior of exiting vehicles is the consequence of the balance between route plan (mandatory incentive and expectation to improve driving condition (discretionary incentive. In higher traffic density, the latter seems to play a significant role. Furthermore, we found that lane-change from the slow lane to the fast lane would lead to higher speed variance value, which indicates a higher crash risk. The findings contribute to a better understanding on drivers’ natural driving behavior in freeway off-ramp areas and can provide important insight into road network design and safety management strategies.

Pharmacokinetic Modeling of Voriconazole To Develop an Alternative Dosing Regimen in Children.

Science.gov (United States)

Gastine, Silke; Lehrnbecher, Thomas; Müller, Carsten; Farowski, Fedja; Bader, Peter; Ullmann-Moskovits, Judith; Cornely, Oliver A; Groll, Andreas H; Hempel, Georg

2018-01-01

The pharmacokinetic variability of voriconazole (VCZ) in immunocompromised children is high, and adequate exposure, particularly in the first days of therapy, is uncertain. A population pharmacokinetic model was developed to explore VCZ exposure in plasma after alternative dosing regimens. Concentration data were obtained from a pediatric phase II study. Nonlinear mixed effects modeling was used to develop the model. Monte Carlo simulations were performed to test an array of three-times-daily (TID) intravenous dosing regimens in children 2 to 12 years of age. A two-compartment model with first-order absorption, nonlinear Michaelis-Menten elimination, and allometric scaling best described the data (maximal kinetic velocity for nonlinear Michaelis-Menten clearance [ V max ] = 51.5 mg/h/70 kg, central volume of distribution [ V 1 ] = 228 liters/70 kg, intercompartmental clearance [ Q ] = 21.9 liters/h/70 kg, peripheral volume of distribution [ V 2 ] = 1,430 liters/70 kg, bioavailability [ F ] = 59.4%, K m = fixed value of 1.15 mg/liter, absorption rate constant = fixed value of 1.19 h -1 ). Interindividual variabilities for V max , V 1 , Q , and F were 63.6%, 45.4%, 67%, and 1.34% on a logit scale, respectively, and residual variability was 37.8% (proportional error) and 0.0049 mg/liter (additive error). Monte Carlo simulations of a regimen of 9 mg/kg of body weight TID simulated for 24, 48, and 72 h followed by 8 mg/kg two times daily (BID) resulted in improved early target attainment relative to that with the currently recommended BID dosing regimen but no increased rate of accumulation thereafter. Pharmacokinetic modeling suggests that intravenous TID dosing at 9 mg/kg per dose for up to 3 days may result in a substantially higher percentage of children 2 to 12 years of age with adequate exposure to VCZ early during treatment. Before implementation of this regimen in patients, however, validation of exposure, safety, and tolerability in a carefully designed

Route effect on the perception of public transport services quality

Energy Technology Data Exchange (ETDEWEB)

Chica-Olmo, J.; Gachs-Sanchez, H.M.; Lizarraga, C.

2016-07-01

User satisfaction sets a basic example for public service quality, especially those considered as basic necessities. The quality in transport service related to conceptualization and measurement, as a decisive demand key, presents challenges for both economic and mobility policies.Several operator companies are involved in the transport sector. Therefore this report aims to design a model of overall satisfaction based on the level of satisfaction with a specific set of factors, considering individual characteristics of users and the differential effect of different bus lines.The current presentation has applied a combined method, using Nonlinear Principal Component Analysis (NLPCA) and a Logit Multilevel Model (LMLM) in two-steps. (Author)

Demand for alternative-fuel vehicles when registration taxes are high

DEFF Research Database (Denmark)

Mabit, Stefan Lindhard; Fosgerau, Mogens

2011-01-01

This paper investigates the potential futures for alternative-fuel vehicles in Denmark, where the vehicle registration tax is very high and large tax rebates can be given. A large stated choice dataset has been collected concerning vehicle choice among conventional, hydrogen, hybrid, bio......-diesel, and electric vehicles. We estimate a mixed logit model that improves on previous contributions by controlling for reference dependence and allowing for correlation of random effects. Both improvements are found to be important. An application of the model shows that alternative-fuel vehicles with present...... technology could obtain fairly high market shares given tax regulations possible in the present high-tax vehicle market....

Early Warning Systems, the Case of Turkey = Erken Uyarı Sistemleri, Türkiye Uygulaması

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Sinan AKTAN

2005-01-01

Full Text Available We are focusing on two alternative techniques that can be used empirically to select predictors for failure prediction purposes. The selected techniques have all different assumptions about the relationships between the independent variables. Linear discriminant analysis is based on linear combination of independent variables; logit analysis uses logistic cumulative probability distribution function. Our aim is to study if these essential differences between methods affect the empirical selection of independent variables to the models and lead significant differences in failure prediction accuracy; moreover, develop a prediction model that would be benefited by management itself, shareholders, government, vendors, creditors, investors and other stakeholders in their projections and strategies.

A new parameterization for integrated population models to document amphibian reintroductions.

Science.gov (United States)

Duarte, Adam; Pearl, Christopher A; Adams, Michael J; Peterson, James T

2017-09-01

Managers are increasingly implementing reintroduction programs as part of a global effort to alleviate amphibian declines. Given uncertainty in factors affecting populations and a need to make recurring decisions to achieve objectives, adaptive management is a useful component of these efforts. A major impediment to the estimation of demographic rates often used to parameterize and refine decision-support models is that life-stage-specific monitoring data are frequently sparse for amphibians. We developed a new parameterization for integrated population models to match the ecology of amphibians and capitalize on relatively inexpensive monitoring data to document amphibian reintroductions. We evaluate the capability of this model by fitting it to Oregon spotted frog (Rana pretiosa) monitoring data collected from 2007 to 2014 following their reintroduction within the Klamath Basin, Oregon, USA. The number of egg masses encountered and the estimated adult and metamorph abundances generally increased following reintroduction. We found that survival probability from egg to metamorph ranged from 0.01 in 2008 to 0.09 in 2009 and was not related to minimum spring temperatures, metamorph survival probability ranged from 0.13 in 2010-2011 to 0.86 in 2012-2013 and was positively related to mean monthly temperatures (logit-scale slope = 2.37), adult survival probability was lower for founders (0.40) than individuals recruited after reintroduction (0.56), and the mean number of egg masses per adult female was 0.74. Our study is the first to test hypotheses concerning Oregon spotted frog egg-to-metamorph and metamorph-to-adult transition probabilities in the wild and document their response at multiple life stages following reintroduction. Furthermore, we provide an example to illustrate how the structure of our integrated population model serves as a useful foundation for amphibian decision-support models within adaptive management programs. The integration of multiple, but

Dose escalation with 3-D CRT in prostate cancer: five year dose responses and optimal treatment

International Nuclear Information System (INIS)

Hanks, Gerald; Hanlon, Alexandra; Pinover, Wayne; Hunt, Margie; Movsas, Benjamin; Schultheiss, Timothy

1997-01-01

Purpose: To report 5 yr dose responses in prostate cancer patients treated with 3D-CRT and describe optimal treatment based on dose response. Methods: Dose escalation was studied in 233 consecutive patients treated with 3D-CRT between 3/89 and 10/92. All surviving patients have >32 mo follow-up, the median follow-up is 55 mo. Estimated logistic cumulative distribution functions (logit response models) fit to 5 yr actuarial bNED outcome are reported for 3 dose groups in each of 3 pretreatment PSA groupings (10-19.9 ng/ml and 20+ ng/ml); no dose response is observed for patients with pretreatment PSA <10 ng/ml. Logit response models fit to 5 yr actuarial late morbidity rates (grade 2 GI, grade 2 GU, grade 3,4 GI) are also reported for 4 dose groups. Patients are treated with CT planned 4-field conformal technique where the PTV encompasses the CTV by 1.0 cm in all directions including the anterior rectal wall margin. Patients are followed at 6 mo intervals with PSA and DRE, and bNED failure is defined as PSA ≥1.5 ng/ml and rising on two consecutive measures. The Fox Chase modification of the LENT morbidity scale is used for GI morbidity including any blood transfusion and/or more than 2 coagulations as a grade 3 event. GU morbidity follows the RTOG scale. Results: The logit response models based on 5 yr bNED results have slopes of 27% and 18% for pretreatment PSA grouping 10-19.9 ng/ml and 20+ ng/ml, respectively. The 50% bNED response is observed at 71 Gy and 80 Gy respectively, while the 80% bNED response is observed at 76 Gy for the 10-19.9 ng/ml group and estimated at 88 Gy for the 20+ ng/ml group. Logit dose response models for grade 2 GI and grade 2 GU morbidity show markedly different slopes, 23% versus 4%, respectively. The slope for grade 3,4 GI is 12%. The dose response model indicates grade 3,4 GI complication rates at 5 yrs are 8% at 76 Gy and 12% at 80 Gy. Conclusion: Based on 5 yr results, we can draw some conclusions about appropriate dose from these

ON THE PERFORMANCE OF ARTIFICIAL INTELLIGENCEMETHODS FOR FAILURE PREDICTION: EVIDENCE FROMISTANBUL STOCK EXCHANGE

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Dr Hakan Er

2014-01-01

Full Text Available The prediction of business failure is a widely studied subject in financialliterature. Many earlier studies on this topic employed statistical methods such asmultiple discriminant analysis, logit and probit topredict corporate failure usingpast financial data (especially the ratio data. However, there has been a recentsurge in academic interest in the use of artificialintelligence (AI methods topredict financial distress. Numerous studies documented that AI methodsoutperform traditional methods. Majority of these studies used data fromestablished markets, the number of studies on emerging market data is ratherlimited and only a handful of studies employed Turkish data for analysis. Thisstudy aims to contribute to the literature by applying the artificial neural networksto predict deletions from Istanbul Stock Exchange (ISE National 100 Index. Thesample is constructed using the quarterly fundamental data of the companies listedin this index the period between January 2008 and December 2012. We employedNeural Networks (NN, logit and probit to predict deletions from index onequarter before they have occurred. Results show that although the logit providesslightly better in-sample predictions, all of the methods fail to identify deletions inthe out-of-sample periods.

Determinants of Food Security Status of Maize-Based Farming Households in Southern Guinea Savannah Area of Oyo State, Nigeria.

Directory of Open Access Journals (Sweden)

Oluwayemisi Abidemi Onasanya

2016-05-01

Full Text Available Nigeria is one of the countries in sub-Saharan Africa with insufficient food and high food import bill, which have debilitating effects on the productive capacity of the citizens. Maize is the most important cereal after rice and its production contributes immensely to food availability on the tables of many Nigerians. This study examined the contribution of maize production to household food security status of rural maize-farming households in the southern guinea savannah of Oyo state, Nigeria. A multistage sampling procedure was used to select 200 farm households and the data were analysed using descriptive statistics, recommended daily calorie requirement (RDCR approach, Logit model. Results showed that about three-quarters of the households were food secure and were able to meet the recommended calorie intake of 2260Kcal per capita per day. The shortfall index (P which measures the extent of deviation from the food security line, indicated that the food secure households exceeded the RDCR by 65%, while the food insecure households fell short of the RDCR by 31%. The logit model showed that maize output, gender, primary occupation of the farmer, farm size and farming experience had a positive influence on food security status while age had a negative influence on the food security status of maize-based farming households in the Southern Guinea Savannah of Oyo State, Nigeria. This suggests need for specific support to improve maize production

Treatment preferences of originator versus biosimilar drugs in Crohn's disease; discrete choice experiment among gastroenterologists.

Science.gov (United States)

Baji, Petra; Gulácsi, László; Lovász, Barbara D; Golovics, Petra A; Brodszky, Valentin; Péntek, Márta; Rencz, Fanni; Lakatos, Péter L

2016-01-01

To explore preferences of gastroenterologists for biosimilar drugs in Crohn's disease. Discrete choice experiment was carried out involving 51 Hungarian gastroenterologists in May 2014. The following attributes were used to describe hypothetical choice sets: 1) type of the treatment (biosimilar/originator), 2) severity of disease, 3) availability of continuous medicine supply, 4) frequency of the efficacy check-ups. Multinomial logit model was used to differentiate between three attitude types: 1) always opting for the originator, 2) willing to consider biosimilar for biological-naïve patients only, 3) willing to consider biosimilar treatment for both types of patients. Conditional logit model was used to estimate the probabilities of choosing a given profile. Men, senior consultants, working in inflammatory bowel disease center and treating more patients were more likely willing to consider biosimilar for biological-naïve patients only. Treatment type (originator/biosimilar) was the most important determinant of choice for patients already treated with biologicals, and the availability of continuous medicine supply in case of biological-naïve patients. The probabilities of choosing the biosimilar with all the benefits offered over the originator under current reimbursement conditions are 89% versus 11% for new patients, and 44% versus 56% for patients already treated with biological. For gastroenterologist, the continuous medical supply would be one of the major benefits of biosimilars. However, benefits offered in the scenarios do not compensate for the change from the originator to the biosimilar treatment of patients already treated with biologicals.

Use of two-part regression calibration model to correct for measurement error in episodically consumed foods in a single-replicate study design: EPIC case study.

Science.gov (United States)

Agogo, George O; van der Voet, Hilko; van't Veer, Pieter; Ferrari, Pietro; Leenders, Max; Muller, David C; Sánchez-Cantalejo, Emilio; Bamia, Christina; Braaten, Tonje; Knüppel, Sven; Johansson, Ingegerd; van Eeuwijk, Fred A; Boshuizen, Hendriek

2014-01-01

In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted two-part regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM) and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC) study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model.

Spatio-temporal Dynamics of Land-use and Land-cover Change: A Multi-agent Simulation Model and Its Application to an Upland Watershed in Central Vietnam

Science.gov (United States)

Le, Q.; Vlek, P. L.; Park, S.

2005-12-01

Land-use and land-cover change (LUCC) is an essential environmental process that should be monitored and prognosticated to provide a basis for better land management policy. However, LUCC modeling is a challenge due to the complex nature and unexpected behavior of both human drivers and natural constraints. This paper presents a multi-agent-based model to simulate spatio-temporal land-use changes and the interdependent socio-economic dynamics emerging from the complex socio-ecological interactions at micro levels resulting from land-use policy interventions. The model provides land-use scenarios under alternative policy to support decisions on land management for improved rural livelihoods while protecting the environment. In the multi-agent simulation model, the human community is represented by household agents (heterogeneous farming households) with their profiles and decision-making mechanisms about land use. The household profile defines the five asset dimensions of household livelihood (e.g., social, human, financial, natural and physical assets). The land-use decision-making program works by taking inputs from the household profile, perceived spatial environmental attributes, and introduced policies. The decision-making program is a logical procedure that combines a land-use choice model (multi-nominal logistic choices) and anthropological rules. The landscape environment is represented by landscape agents (congruent land patches of 30mx30m) with their state variables and ecological response mechanisms to environmental changes and human interventions. State variables of landscape agents correspond to spatial GIS-raster layers of biophysical, economic, and institutional variables. Ecological mechanisms of landscape agents are represented by internal sub-models of agricultural and forest productivity dynamics, which work in response to the current state, history, and spatial neighbourhood of the landscape agents. A multi-agent based protocol coordinates the

Consumer Credit Card Use Intention and Influence Factors Analysis

Directory of Open Access Journals (Sweden)

Wang Yantao

2017-01-01

Full Text Available Credit card as a kind of advanced means of payment and the new way of consumer credit in the world widely, but in our country is faced with some problems, such as their per capita spending is low, open the card number is small, motionless bank card is a lot. In this paper, using the Logit model to analyze the Anshan city in Liaoning province consumer credit card usage. And combined with empirical analysis to provide banking management Suggestions and marketing countermeasures, including targeted to provide different kinds of credit card.

Child Labour or School Attendance? Evidence from Zambia

DEFF Research Database (Denmark)

Jensen, Peter; Nielsen, Helena Skyt

1996-01-01

In this paper, we investigate what affects school attendance and child labour in an LDC, using data for Zambia. Since the data come from a household survey with information on all household members, it allows us to take account of unobserved household effects by introducing household specific...... effects in a logit model. The empirical analysis suggests that both economic and sociological variables are important determinants for the choice between school attendance and child labour. In particular, we find some support for the hypothesis that poverty forces households to keep their children away...

Determinants of perceived value and repurchase intentions in brazilian inbound tourism

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Glauber Eduardo de Oliveira Santos

2009-12-01

Full Text Available This study aims to measure the influence of Brazilian tourism product’s characteristics on the inbound tourist’s perceived value and the intention to return. An empirical study was carried out using a large database contents on international tourism behavior. The logit binomial model was used for estimation. As a result it was found that some of the most relevant characteristics of Brazilian tourism product are hospitality, accommodation, nightlife, public safety and tour guides. Among the least significant aspects are public transport, highways, communication system and tourist signage.

Choice probability generating functions

DEFF Research Database (Denmark)

Fosgerau, Mogens; McFadden, Daniel; Bierlaire, Michel

2013-01-01

This paper considers discrete choice, with choice probabilities coming from maximization of preferences from a random utility field perturbed by additive location shifters (ARUM). Any ARUM can be characterized by a choice-probability generating function (CPGF) whose gradient gives the choice...... probabilities, and every CPGF is consistent with an ARUM. We relate CPGF to multivariate extreme value distributions, and review and extend methods for constructing CPGF for applications. The choice probabilities of any ARUM may be approximated by a cross-nested logit model. The results for ARUM are extended...

Evolutionary games combining two or three pair coordinations on a square lattice

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Király, Balázs; Szabó, György

2017-10-01

We study multiagent logit-rule-driven evolutionary games on a square lattice whose pair interactions are composed of a maximal number of nonoverlapping elementary coordination games describing Ising-type interactions between just two of the available strategies. Using Monte Carlo simulations we investigate the macroscopic noise-level-dependent behavior of the two- and three-pair games and the critical properties of the continuous phase transtitions these systems exhibit. The four-strategy game is shown to be equivalent to a system that consists of two independent and identical Ising models.

With Health and Good Food, Great Life!

DEFF Research Database (Denmark)

Lobos, Germán; Grunert, Klaus G; Bustamante, Miguel

2016-01-01

and multiple comparison tests. Ordered logit models were computed to examine the determinants of happiness. We find that satisfaction related to food, perception of health and functionality are significantly linked to individual happiness within both gender groups. An influential predictor of female...... with an inflection point at the age of 77.5 years. This research suggests that the design and formulation of public policies on rural older adults should consider subjective welfare factors they perceive as predictors of happiness and not only objective factors related to well-being....

Estimating the impact of investment tax credits on aircraft demand

OpenAIRE

Mackay, Daniel

2011-01-01

This paper uses exogenous price changes from the shifting tax policies of the 1980’s to identify the parameters of a nested-logit discrete choice model of the aircraft market. The federal Investment Tax Credit (ITC) was a tax credit of 6-10% of a firm's new capital investment that was removed by the Tax Reform Act of 1986 (TRA86). Such tax credits continue to be proposed as tools to spur investment, and they are still utlized in many states and select industries. This research adds to the ...

Determinants of SME credit worthiness under Basel rules: the value of credit history information

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Francesco Dainelli

2013-03-01

Full Text Available The Basel III Accord has reportedly had an impact on SME financing. In this paper, we aim to highlight the determinants of SME credit worthiness. We use credit history in addition to financial ratios and “hybrid” indicators that have been built by mixing credit history with financial statement data. We develop a failure prediction logit model on 187 Italian SMEs. The use of short-term credit lines is the most important variable. Contrary to common understanding, capitalization levels do not affect ratings. Lastly, credit worthiness is sensitive to sale profitability.

The Effect of Advertising and In-Store Promotion on the Demand for Chocolate

OpenAIRE

Jason C. Patalinghug

2013-01-01

This paper analyzes the effect of TV advertising and in-store displays on the sales of chocolates. I examine which method is more effective in gaining customers and in increasing total sales. Also, I look at the evidence to see whether the lack of advertising by a firm will hurt the industry as a whole. In this essay, I use a nested logit model on scanner data obtained by the Zwick Center for Food and Resource Policy at the University of Connecticut's Department of Agricultural and Resource E...

Gardening is beneficial for adult mental health: Scottish Health Survey, 2012-2013.

Science.gov (United States)

Shiue, Ivy

2016-07-01

Gardening has been reported as being beneficial for mental well-being for vulnerable populations since 2000. However, little is known concerning its role in the general population. Therefore, the aim of the present study was to investigate the relationship of gardening and mental health in adults in a countrywide and population-based setting. Data was retrieved from and analysed in the Scottish Health Survey, 2012-2013. Information on demographics, lifestyle factors, gardening engagement, and adult mental health by General Health Questionnaire was obtained by household interview. Statistical analyses including chi-square test, t-test and survey-weighted logistic and multi-nominal regression modelling were performed. Of 9709 Scottish adults aged 16-99, 5 531 (57.0%) people did not do any gardening or building work in the last four weeks. A total of 888 (9.2%) people reported poor self-rated health. Gardening was associated with adult mental health in people both with or without heart conditions including ability to concentrate, feeling playing a useful part in things, feeling capable of making decisions, thinking of self as worthless, feeling reasonably happy, etc. General adults with or without heart conditions could benefit from engaging with gardening or building work. Future public health programmes promoting such activity should be encouraged in order to optimise adult mental health.

Depressive and anxiety disorders on-the-job: the importance of job characteristics for good work functioning in persons with depressive and anxiety disorders.

Science.gov (United States)

Plaisier, Inger; de Graaf, Ron; de Bruijn, Jeanne; Smit, Johannes; van Dyck, Richard; Beekman, Aartjan; Penninx, Brenda

2012-12-30

This study examines the importance of job characteristics on absence and on-the-job performance in a large group of employees with diagnosed depressive and anxiety disorders. In a sample of 1522 employees (1129 persons with and 393 persons without psychopathology) participating in Netherlands Study of Depression and Anxiety (NESDA, n=2981) we examined associations between job characteristics and work functioning (absenteeism and work performance) in multinominal logistic regression models. Job characteristics were working hours, psychosocial working conditions and occupational status. As expected, depressed and anxious patients were at significantly elevated risk for absenteeism and poor work performance. In analyses adjusted for psychopathology, absenteeism and poor performance were significantly lower among persons reporting high job support, high job control, less working hours, self-employed and high skilled jobs. Associations were comparable between persons with and without psychopathology. High job support, high job control and reduced working hours were partially related to work functioning in both workers with- and without-psychopathology. Since depressed and anxious employees are at a substantially increased risk for absenteeism and poor work performance, strategies that improve job support and feelings of control at work may be especially helpful to prevent poor work functioning in this at-risk group of employees. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Reasons for Engagement: SME Owner-manager Motivations for Engaging in a Workplace Mental Health and Wellbeing Intervention.

Science.gov (United States)

Dawkins, Sarah; Martin, Angela; Kilpatrick, Michelle; Scott, Jenn

2018-05-30

Small-to-medium enterprises (SMEs) require specialized attention regarding workplace mental health (WMH), but can be challenging to engage in WMH promotion interventions. This cross-sectional study analyzed self-reported motivations of SME owner/managers who engaged in a WMH promotion intervention specifically designed for SMEs. Data from 297 SME owner/managers was thematically coded prior to conducting multinominal logistical regression analyses to determine reasons for engagement based on a series of predictors, including owner/manager psychological distress, recent experience of a stressful work event, and business confidence. Owner/manager psychological distress, experience of a recent stressful workplace, and low 12-month business confidence incident were important predictors of engagement. The findings provide important insights into the uptake of a WMH promotion intervention, which can inform the design and future recruitment strategies for WMH promotion interventions within the SME sector.