Bus is the main mode of urban transport in most cities in developing countries. Despite a high mode share, bus service quality is often poor and para-transit services are regarded as a problem in urban transport systems rather than a solution. Using Dhaka as a case study, this thesis investigates bus service quality through identification and valuation of thirteen important attributes using discrete choice models. The attributes examined are travel time, travel cost, waiting time, headway, priority seats for women, crowding inside the bus, boarding and alighting, picking up and dropping off passengers, bus stop facilities, driving quality, driver and crew behaviour, cleanliness inside the bus, and air conditioning. Five focus groups were conducted to identify key qualitative bus attributes and their levels in order to design choice experiments for valuation. A survey of 431 respondents in Dhaka was then undertaken. Two choice experiments were designed and implemented within the survey, each with seven attributes (set A and set B) with travel cost as the common attribute. Multinomial Logit (MNL) models and Mixed Logit (MXL) models were developed using the Dhaka choice data. Twelve of the thirteen attributes were statistically significant at the 99% level. The values of in-vehicle time (IVT), waiting time and headway were BDT 34.80, 47.40 and 64.20 per hour respectively for low income groups in the segmented model. Waiting time has a premium valuation, 1.36 times higher than IVT, which endorses existing evidence. The highest valuation is for the dummy variable seating all the way which is BDT 42.20 for high income females. The next largest was bus stops properly, picks and drops passengers nicely , followed by wide door and mild steps for boarding and alighting , smooth and safe journey , bus stop with shed, but no seating arrangements , and air conditioning . The lowest value was BDT 4.61 for deck and seats are clean and tidy , for the low income group. The WTP for the qualitative attributes is high, but given the poor level of the existing service and low fare levels this seems reasonable. Income has a significant impact on travel cost, as well as gender on priority seats for women and crowding inside the bus. However, household car ownership does not have a significant impact on any of the bus attributes examined. The high income group has 75% higher WTP for A set attributes and 79% higher WTP for B set attributes than low income group. Females have 76% higher WTP for standing comfortably all the way , but 38% higher WTP for seating all the way compared to the male. However, females have a WTP of BDT 0.44 for per percent of priority seats for women in contrast with males who have a WTP of BDT -0.11. There is significant taste heterogeneity for both quantitative and qualitative attributes. The qualitative attributes for picking up and dropping off passengers, boarding and alighting facilities and driving facilities have higher valuation and this attributes came from the existing within the market competition structure in a highly fragmented bus market. Therefore, it is recommended to introduce competition for the market and incentives for bus industry consolidation.

A large body of literature studies the issues of the option price and other ex-ante welfare measures under the microeconomic theory to valuate reductions of risks inherent in environment and human health. However, it does not offer a careful discussion of how to estimate risk reduction values using data, especially the modeling and estimating individual perceptions of risks present in the econometric models. The central theme of my dissertation is the approaches taken for the empirical estimation of probabilistic risks under alternative assumptions about individual perceptions of risk involved: the objective probability, the Savage subjective probability, and the subjective distributions of probability. Each of these three types of risk specifications is covered in one of the three essays. The first essay addresses the problem of empirical estimation of individual willingness to pay for recreation access to public land under uncertainty. In this essay I developed an econometric model and applied it to the case of lottery-rationed hunting permits. The empirical result finds that the model correctly predicts the responses of 84% of the respondents in the Maine moose hunting survey. The second essay addresses the estimation of a logit model for individual binary choices that involve heterogeneity in subjective probabilities. For this problem, I introduce the use of the hierarchical Bayes to estimate, among others, the parameters of distribution of subjective probabilities. The Monte Carlo study finds the estimator asymptotically unbiased and efficient. The third essay addresses the problem of modeling perceived mortality risks from arsenic concentrations in drinking water. I estimated a formal model that allows for ambiguity about risk. The empirical findings revealed that perceived risk was positively associated with exposure levels and also related individuating factors, in particular smoking habits and one’s current health status. Further evidence was found that the variance of the perceived risk distribution is non-zero. In all, the three essays contribute methodological approaches and provide empirical examples for developing empirical models and estimating value of risk reductions in environment and human health, given the assumption about the individual’s perceptions of risk, and accordingly, the reasonable specifications of risks involved in the models.

Understanding joint and causal relationships among multiple endogenous variables has been of much interest to researchers in the field of activity and travel behavior modeling. Structural equation models have been widely developed for modeling and analyzing the causal relationships among travel time, activity duration, car ownership, trip frequency and activity frequency. In the model, travel time and activity duration are treated as continuous variables, while car ownership, trip frequency and activity frequency as ordered discrete variables. However, many endogenous variables of interest in travel behavior are not continuous or ordered discrete but unordered discrete in nature, such as mode choice, destination choice, trip chaining pattern and time-of-day choice (it can be classified into a few categories such as AM peak, midday, PM peak and off-peak). A modeling methodology with involvement of unordered discrete variables is highly desired for better understanding the causal relationships among these variables. Under this background, the proposed dissertation study will be dedicated into seeking an appropriate modeling methodology which aids in identifying the causal relationships among activity and travel variables including unordered discrete variables. In this dissertation, the proposed modeling methodologies are applied for modeling the causal relationship between three pairs of endogenous variables: trip chaining pattern vs. mode choice, activity timing vs. duration and trip departure time vs.mode choice. The data used for modeling analysis is extracted from Swiss Travel Microcensus 2000. Such models provide us with rigorous criteria in selecting a reasonable application sequence of sub-models in the activity-based travel demand model system.

Submitted by Letícia Nunes (leticiafcnunes@gmail.com) on 2015-06-11T16:44:52Z No. of bitstreams: 1 Dissertação - Leticia Nunes - Practice Location of Physicians.pdf: 569206 bytes, checksum: bde07c17bc4ab59a76a947e9fa27f35e (MD5) / Approved for entry into archive by BRUNA BARROS (bruna.barros@fgv.br) on 2015-06-18T13:46:34Z (GMT) No. of bitstreams: 1 Dissertação - Leticia Nunes - Practice Location of Physicians.pdf: 569206 bytes, checksum: bde07c17bc4ab59a76a947e9fa27f35e (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2015-06-29T12:13:05Z (GMT) No. of bitstreams: 1 Dissertação - Leticia Nunes - Practice Location of Physicians.pdf: 569206 bytes, checksum: bde07c17bc4ab59a76a947e9fa27f35e (MD5) / Made available in DSpace on 2015-06-29T12:13:22Z (GMT). No. of bitstreams: 1 Dissertação - Leticia Nunes - Practice Location of Physicians.pdf: 569206 bytes, checksum: bde07c17bc4ab59a76a947e9fa27f35e (MD5) Previous issue date: 2015-04-07 / Economists and policymakers have long been concerned with increasing the supply of health professionals in rural and remote areas. This work seeks to understand which factors influence physicians’ choice of practice location right after completing residency. Differently from previous papers, we analyse the Brazilian missalocation and assess the particularities of developing countries. We use a discrete choice model approach with a multinomial logit specification. Two rich databases are employed containing the location and wage of formally employed physicians as well as details from their post-graduation. Our main findings are that amenities matter, physicians have a strong tendency to remain in the region they completed residency and salaries are significant in the choice of urban, but not rural, communities. We conjecture this is due to attachments built during training and infrastructure concerns.

nÃo hà / O objetivo deste trabalho à estimar a probabilidade de um trabalhador estar empregado no setor informal, condicionadas as suas caracterÃsticas produtivas, considerando a possibilidade de viÃs de seleÃÃo amostral. A amostra se restringe ao CearÃ, e utiliza a Pesquisa Nacional de Amostras por DomicÃlio (PNAD) 2008 para classificar os trabalhadores em formais e informais. De acordo com a hipÃtese da dualidade, os postos de trabalho no setor formal sÃo efetivamente melhores em vÃrias dimensÃes, e a existÃncia de informalidade ocorre porque o nÃmero destes postos à limitado. Se de fato hà segmentaÃÃo no mercado de trabalho e racionamento dos postos de trabalho formais, à importante saber como ocorre à alocaÃÃo de trabalhadores entre os dois setores. Para tanto, à considerada a possibilidade de viÃs de seleÃÃo na escolha entre os setores formal e informal. O viÃs de seleÃÃo ocorre quando uma sÃrie de caracterÃsticas nÃo observÃveis dos indivÃduos pode fazer com que eles acabem trabalhando, por opÃÃo ou necessidade, no setor informal da economia. Ou seja, caracterÃsticas nÃo observÃveis dos indivÃduos, como habilidade, forÃa de vontade, determinaÃÃo, criatividade etc., podem estar determinando a escolha entre trabalhar no mercado formal ou informal. / The aim of this study to estimate the probability of a worker being employed in the informal sector conditioned their productive characteristics, considering the possibility of sample selection bias. The sample is restricted to CearÃ, and uses the National Survey of Household Sample Survey (PNAD) in 2008 to classify workers in formal and informal. According to the dual hypothesis, the jobs in the formal sector are indeed better in many dimensions, and the existence of informality is because the number of these jobs is limited. If indeed there is segmentation in the labor market and rationing of formal jobs, it is important to know how the allocation of workers between the two sectors. For this is considered the possibility of selection bias in the choice between formal and informal sectors. The selection bias occurs when a number of unobservable characteristics of individuals can make them end up working, by choice or necessity, in the informal economy. That is, unobservable characteristics of individuals such as skill, willpower, determination, creativity etc., it may be influencing the choice between working in the formal or informal.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18255号 / 工博第3847号 / 新制||工||1590(附属図書館) / 31113 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 小林 潔司, 准教授 宇野 伸宏, 准教授 松島 格也 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

My dissertation consists of three essays on labor supply responses, along the extensive margin (participation into the labor force) and along the intensive margin (intensity of work on the job). The first two essays focus on the labor supply responsiveness of single women with children to taxation and welfare programs. The third essay investigates the effects of marriage, the wage rate, and the associated tax rate on men's labor supply. In the first essay, to avoid bias from the fact that labor supply outcomes are being driven by self-selection, I build a dynamic stochastic discrete choice model to investigate the long run effects of the earned income tax credit and welfare policies on single mothers' labor supply. Simulated method of moments is used to estimate parameters of this dynamic model, based on March CPS data files from 1964 to 2013. I compare the performance of the dynamic stochastic discrete choice model, a static model, and a reduced-form model. My analysis concludes that the dynamic stochastic discrete choice model captures the simultaneous impact of the state variables on the predicted employment decision. My study provides evidence of the long-run positive effect of public policy on low income families in a life-cycle setting. This essay also emphasizes the importance of education in increasing single mothers' labor supply. The second essay is designed to identify factors that help single mothers leave TANF within a short span of time. I find strong evidence for the importance of child support assistance to single mothers' success in exiting TANF with a job. I uncover evidence that work-related activities do not induce TANF participants to leave within a short span of time. My analysis also suggests that health issues significantly limit the ability of single mothers to exit TANF. In the third essay, the main research question is how marital status affects the elasticity of the labor supply of males with respect to wages and taxes, in a life-cycle setting. A dynamic panel data model, which extends the literature on dynamic labor supply, indicates that the elasticity of men's labor supply with respect to wages and taxes is affected by marital status. The empirical results using the Panel Study of Income Dynamics (PSID) data show that men who are continuously married to the same wife have a lower average Frisch elasticity than others. / Ph. D.

Apresenta-se um procedimento para estimativa da matriz origem-destino (O/D) a partir de um modelo de escolha discreta em combinação com uma matriz O/D de transporte público, a qual pode ser estimada de maneira relativamente fácil e rápida. O modelo de escolha discreta utilizado para realizar a divisão modal é o modelo logit multinomial. A calibração do modelo logit é realizada com base em 505 observações e considerando três situações: a população de viajantes sem segmentação, com segmentação segundo posse de automóvel no domicílio, e com segmentação segundo a distância de viagem. Analisa-se a precisão da estimativa do número de viagens quando as zonas de controle que formam a área de estudo são divididas segundo o critério de distância de acesso às linhas de ônibus. Na verificação realizada são empregados dados obtidos da pesquisa domiciliar realizada na cidade de Bauru, SP. Os erros cometidos na estimativa são medidos e comparados com os resultados obtidos na pesquisa domiciliar sem expansão. O trabalho demostrou experimentalmente que o procedimento proposto é uma alternativa viável para se obter a distribuição de viagens e, portanto, para determinar a matriz O/D. / A procedure is presented for estimating an origin-destination (O/D) matrix using a discrete choice model jointly with a public transport O/D matrix; the latter being relatively easy and fast to obtain. A multinomial logit discrete choice model is used to determine the mode split of travelers among several available modes. The model is estimated using a sample of 505 observations chosen from a household 0/D survey in the city of Bauru, state of Sao Paulo. This survey is used throughout to verify the results of the proposed methodology. Three different models are considered: one without segmentation of the population, one with segmentation according to car ownership and one with segmentation according to travel distance. An examination is made of the changes on the level of precision of the number of trips estimated with the division of the control zones that conform the study area; the aforementioned division was carried out on the basis of an access distance to the bus network criterion. The estimation errors are measured and compared to the unexpanded O/D survey results. The research shows empirically that the proposed procedure can be used to obtain the distribution of trips and hence to determine an aggregate O/D matrix.

Apresenta-se um procedimento para estimativa da matriz origem-destino (O/D) a partir de um modelo de escolha discreta em combinação com uma matriz O/D de transporte público, a qual pode ser estimada de maneira relativamente fácil e rápida. O modelo de escolha discreta utilizado para realizar a divisão modal é o modelo logit multinomial. A calibração do modelo logit é realizada com base em 505 observações e considerando três situações: a população de viajantes sem segmentação, com segmentação segundo posse de automóvel no domicílio, e com segmentação segundo a distância de viagem. Analisa-se a precisão da estimativa do número de viagens quando as zonas de controle que formam a área de estudo são divididas segundo o critério de distância de acesso às linhas de ônibus. Na verificação realizada são empregados dados obtidos da pesquisa domiciliar realizada na cidade de Bauru, SP. Os erros cometidos na estimativa são medidos e comparados com os resultados obtidos na pesquisa domiciliar sem expansão. O trabalho demostrou experimentalmente que o procedimento proposto é uma alternativa viável para se obter a distribuição de viagens e, portanto, para determinar a matriz O/D. / A procedure is presented for estimating an origin-destination (O/D) matrix using a discrete choice model jointly with a public transport O/D matrix; the latter being relatively easy and fast to obtain. A multinomial logit discrete choice model is used to determine the mode split of travelers among several available modes. The model is estimated using a sample of 505 observations chosen from a household 0/D survey in the city of Bauru, state of Sao Paulo. This survey is used throughout to verify the results of the proposed methodology. Three different models are considered: one without segmentation of the population, one with segmentation according to car ownership and one with segmentation according to travel distance. An examination is made of the changes on the level of precision of the number of trips estimated with the division of the control zones that conform the study area; the aforementioned division was carried out on the basis of an access distance to the bus network criterion. The estimation errors are measured and compared to the unexpanded O/D survey results. The research shows empirically that the proposed procedure can be used to obtain the distribution of trips and hence to determine an aggregate O/D matrix.

In both developed and emerging-economies, major cities continue to experience increasing traffic congestion. To address this issue, complex Traffic Management Systems (TMS) are employed in recent years to help manage traffic. These systems fuse traffic-surveillance-related information from a variety of sensors deployed across traffic networks. A TMS requires real-time information to make effective control decisions and to deliver trustworthy information to users, such as travel time, congestion level, etc. There are three fundamental inputs required by TMS, namely, traffic volume, vehicular speed, and traffic density. Using conventional traffic loop detectors one can directly measure flow and velocity. However, traffic density is more difficult to measure. The situation becomes more difficult for multi-lane motorways due to drivers lane-change behaviour. This research investigates statistical modelling and analysis of traffic flow. It contributes to the literature of transportation and traffic management and research in several aspects. First, it takes into account lane-changes in traffic modelling through incorporating a Markov chain model to describe the drivers lane-change behaviour. Secondly, the lane change probabilities between two adjacent lanes are not assumed to be fixed but rather they depend on the current traffic condition. A discrete choice model is used to capture drivers lane choice behaviour. The drivers choice probabilities are modelled by several traffic-condition related attributes such as vehicle time headway, traffic density and speed. This results in a highly nonlinear state equation for traffic density. To address the issue of high nonlinearity of the state space model, the EKF and UKF is used to estimate the traffic density recursively. In addition, a new transformation approach has been proposed to transform the observation equation from a nonlinear form to a linear one so that the potential approximation in the EKF & UKF can be avoided. Numerical studies have been conducted to investigate the performance of the developed method. The proposed method outperformed the existing methods for traffic density estimation in simulation studies. Furthermore, it is shown that the computational cost for updating the estimate of traffic densities for a multi-lane motorway is kept at a minimum so that online applications are feasible in practice. Consequently the traffic densities can be monitored and the relevant information can be fed into the traffic management system of interest.