<p>In problems of spatial choice, the choice set is often more aggregated than the one considered by decision-makers, typically because choice data are available only at the aggregate level. These aggregate choice units will exhibit heterogeneity in utility and in size. To be consistent with utility maximization, a choice model must estimate choice probabilities on the basis of the maximum utility within heterogeneous aggregates. The ordinary multinomial logit model (OMNL) applied to aggregate choice units fails this criterion as it is estimated on the basis of average utility. In this thesis, the aggregated spatial logit model, which utilizes the theory underlying the nested logit model to estimate the appropriate maximum utilities of aggregates, is derived and discussed. Initially, the theoretical basis for the model is made clear and an asymptotic version of the model is derived. Secondly, the model is tested in a simulated environment to demonstrate that the OMNL model lacks the generality of the aggregated model in the presence of heterogeneous aggregates. Thirdly, full endogenous estimation of the aggregated model is studied with a view toward finding the best optimization algorithm. Finally, with all the elements in place, the model is tested in an application of migration from the Canadian Atlantic Provinces.</p> / Doctor of Philosophy (PhD)

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) is one of the food assistance programs targeted at low-income women, infants and children up to age five by providing foods, nutrition education and other services. Recent updates in food packages provided by WIC include the addition of fruits, vegetables and whole wheat products as well as the removal of whole milk for women and children two years and older. This thesis concentrates on preschool children participants in the WIC program and their milk consumption habits prior to programmatic changes. Analyzing diet preferences of these children is crucial since a quarter of the population of children aged one thorough five participates in the WIC program; as well, they are not eligible to receive whole milk with WIC food packages after the implementation of revisions. The objective is to describe the profile of preschool WIC children and their milk consumption attributes based on the National Food and Nutrition (NATFAN) questionnaire designed and conducted by the Institute for Obesity Research and Program Evaluation at Texas A & M University before the release of the revised WIC food packages. Additionally, findings of the study are compared with the National Health and Nutrition Examination Survey (NHANES) 2005-2006 dataset results. Milk consumption preferences of WIC children are analyzed nationwide and impacts of race, ethnicity, regional, and other demographic characteristics are observed. Using both NATFAN and NHANES datasets provides a comparison of actual and self-reported participation outcomes. Discrete choice models were used in this analysis, in particular binary logit and multinomial logit models. The results of the thesis indicate that WIC preschool children mostly drink whole milk (36.17 percent) and 2 percent fat milk (49.94 percent). Two year old participants, children located in the South and participants whose caregivers are younger and less educated are more likely to consume whole milk. Caucasian children are less likely to choose whole milk and more likely to choose reduced fat milk; African Americans are more likely to select whole milk. Furthermore, diet preferences and knowledge of parents/caregivers play a major role on milk consumption of children. Children whose caregivers are willing to give low-fat milk to children aged two to five are less likely to drink whole milk.

The objective of the study is to analyze the effect of remittances on socio-economic conditions of rural families in Peshawar, and how remittances change the decision-making process of families. This study examines the effects of remittances on local population in three towns of Peshawar, i.e. Hayatabad, Faqir-Abad and Gulberg-area. The study is basically conducted to see how remittances bring changes in the life of the recipients. The research is quantitative, data was collected through questionnaires. For the research, a sample of 300 respondents was selected from three towns in Peshawar District. The results of the research were interpreted through statistical tools, regression model. The Ordinary least square method (OLS) was used to find out the effect of remittances on health sector and investment made by respondents in the form of purchased property and investment made in establishing their own businesses. Along with that, the simple Logit Model was also used. The result is generalized on linear model with link logit and binomial response. Findings stated that the literacy level of the emigrant’s household positively impacted on children’s probability to move to private education. The results reveals that the recipient invest 4% of their income on investment as a form of business and purchasing property while educated people appears not to be interested in investing money in businesses as they want to continue their jobs. Respondent are not using a large portion of their remittances for health perhaps mostly people are entitled to free services from the government. Remittances changed their standard of living and socio economic affairs of the remittances receiving respondents. According to my demographic information about respondents life, the remittances mostly brings changes in the physical part of people life such as Private Education, Personal transport, new houses, investment in buying properties, more electric appliances, bank balance etc., but culturally people are still conservative and believe in cultural values that have been practices by local population for centuries. Following are some main recommendations that this research has identified, Foreign remittances are improving the socio-economic conditions and decision making of rural families, however, their consumption behavior is not inclined towards investment, they rather prefer to enjoy luxurious household’s equipment. Therefore, it is recommended that these families should utilize their resources in more efficient way, and should go for short and long term investment avenues. Government must design policies in order to educate these families and create awareness among them that will enable them to look for sustainable domestic income, which would help the families in the long run. These families follow the norms and traditions, and they prefer sending their children abroad for earning purposes, which in turn is comparatively less profitable idea as compared to sending these children for higher education purpose.

The relationship between monthly transit pass ownership and home-work trip mode choice in the Greater Toronto Area was explored using a logit formulation. A Nested Logit model was specified with the primary mode (non-motorised, auto, transit, or auto access to transit) in the upper level and the pass ownership in the lower transit nests. Inclusive value parameters confirm the chosen structure, and a range of policy sensitive, statistically significant parameters having expected signs and magnitudes reveal differences between socio-economic characteristics of pass holders and non-pass holders. In particular, pass holders are less likely to possess a driver’s license or automobile than non-pass holders, implying that passes can be thought of as complementary mobility tools. Cost parameters, which include differentiated pricing for pass and non-pass holders, result in plausible in-vehicle values of time of approximately $31/hour, $33/hour and $8/hour for auto, auto access to transit, and transit all way, respectively.

The relationship between monthly transit pass ownership and home-work trip mode choice in the Greater Toronto Area was explored using a logit formulation. A Nested Logit model was specified with the primary mode (non-motorised, auto, transit, or auto access to transit) in the upper level and the pass ownership in the lower transit nests. Inclusive value parameters confirm the chosen structure, and a range of policy sensitive, statistically significant parameters having expected signs and magnitudes reveal differences between socio-economic characteristics of pass holders and non-pass holders. In particular, pass holders are less likely to possess a driver’s license or automobile than non-pass holders, implying that passes can be thought of as complementary mobility tools. Cost parameters, which include differentiated pricing for pass and non-pass holders, result in plausible in-vehicle values of time of approximately $31/hour, $33/hour and $8/hour for auto, auto access to transit, and transit all way, respectively.

I estimate two models of consumer health insurance choices where individual attributes and e.g., income, age, gender, cost, etc. affect qualification for specific programs e.g., Medicaid and Medicare, but also affect the choices individuals make. From these results, I assess how these attributes affect health insurance choices using the 2008 Medical Expenditure Panel Survey. I then use these results to predict how individual health insurance choices change with the implementation of the Patient Protection and Affordable Care Act (ACA) in 2014. My predictions estimate that more 50 percent of those who become eligible for Medicaid under ACA will switch to Medicaid or choose to have both Private and Medicaid insurance.

<p> The logit format for a modal split model, which has previously been used for only binary cases, is used to build a new set of behavioural, probabilistic, multi-mode models. The models and the testing were carried out on a CDC 6400 Computer. </p> <p> A program developed at Chicago was used to construct the models while a separate program was developed to analyze the results. The type and number of variables to be used in the different sections of the model were investigated and an attempt was made to find the best method of aggregation. An inferred 'value of time' was also calculated and statistical testing of the individual and aggregate models was made. </p> <p> It is shown that this method of modelling is indeed feasible in terms of the significance of the models and the accuracy of the predictions on a separate data set. </p> / Thesis / Master of Engineering (ME)

On-Demand Mobility (ODM) is a concept to address congestion problems. Using electric aircraft and vertical take-off with limited landing (VTOL) capabilities, the ODM concept offers on demand transportation service between designated landing sites at a fraction of driving time. The purpose of this research is to estimate the potential ODM demand and understand the challenges of introducing ODM using the Northern California region (including major cities like San Francisco, Sacramento, and San Jose) as an area of study and a second, less rigorous analysis for the Washington-Baltimore region. A conditional logit model was developed to estimate mode choice behavior and to estimate ODM demand; presenting automobile and public transportation as the two competing modes to ODM. There are significant challenges associated with the service including ability to operate in bad weather, vehicle operating cost, siting and cost of landing sites, and overall public acceptance of small, remotely operated aircraft. Nine scenarios were run varying the input for a base fare, landing fare, cost per-passenger-mile, auto operational costs, and ingress (waiting) times. The results yielded sensitivity of demand to all these parameters and especially showed a great difference in demand when auto costs were decreased from the standard American Automobile Association (AAA) cost per mile to a likely, future auto operating cost. The challenge that aerospace engineers face is designing an aircraft capable of achieving lower operational costs. The results showed that in order for the ODM to be a competitive mode, the cost per passenger-mile should be kept at $1. / Master of Science / On-Demand Mobility (ODM) is a concept to address congestion problems. Using an electric propulsion aircraft, the ODM concept offers on demand transportation service between designated landing sites at a fraction of driving time; an “air taxi” or “air Uber” as coined by media outlets. The purpose of this research is to estimate the potential ODM demand and understand the challenges of introducing ODM using the Northern California region (including major cities like San Francisco, Sacramento, and San Jose) as an area of study and a second, less rigorous analysis for the Washington-Baltimore region. A model was developed to estimate mode choice behavior and to estimate ODM demand based on existing travel behavior and patterns in the Northern California region. There are significant challenges associated with the service including ability to operate in bad weather, vehicle operating cost, siting and cost of landing sites, and overall public acceptance of small, remotely operated aircraft. The results from the model yielded sensitivity of demand to these challenges and especially showed a great difference in demand as the cost of operating the car decreases in the future, making it a great competitor to the ODM concept. The major challenge that aerospace engineers face is designing an aircraft capable of achieving lower operational costs. The results showed that in order for the ODM to be a competitive mode, the cost per passenger-mile should be kept at $1.

This thesis consists of two parts. The first part analyzesthe accessibility, generation and license holding effects incar ownership models. The second part develops a route choicemodeling framework with an attempt to address the differencesin drivers' route choice behavior. These two parts of work areboth based on the discrete choice theory - the car ownershipmodels are built up on the standard logit model, whereas theroute choice models are formulated in a mixed logit form. The study result of the first part shows that measuring theaccessibility by the monetary inclusive value reasonably wellcaptures the mechanism of the accessibility impact. Otheraccessibility proxies such as the parking costs, parking typeand house type are correlated with the accessibility but not toa great extent. Both young and old households are less likelyto have a car. The reduction of the propensity to own a car issignificant for households with average birth year before 1920,whereas this reduction is moderate for households with birthyear between 1920 and 1945. It is also demonstrated thatdriving license holding choice is conditional on the carownership level choice, and that these two choices need to bemodeled in a dynamic framework. The second part of the work investigates the performance ofthe mixed logit model using both simulated data and empiricalroute switching data. The empirical study mainly focused on theimpacts of information and incident related factors on drivers'route switching behavior. The result shows that using mixed logit gives a significantimprovement in model performance as well as a more sensitiveexplanation of drivers' decision-making behavior. For apopulation with greatly varying tastes, simply using thestandard logit model to analyze its behavior can yield veryunrealistic results. However, care must be taken when settingthe number of random draws for simulating the choiceprobability of the mixed logit model in order to get reliableestimates. The empirical results demonstrate that incident relatedfactors such as delay and information reliability havesignificant impacts on drivers' route switching, where themagnitude of the response to the change in the delay is shownto vary significantly between individuals. Other factors, suchas confidence in the estimated delay, gender, frequency of cardriving and attitude towards congestion, also make majorcontributions. In addition, it is found that individual's routeswitching behavior may differ depending on the purpose of thetrip and when the choice is made, i.e. pre-trip oren-route. <b>Keywords</b>: car ownership, accessibility, logit model,route choice, heterogeneity, mixed logit model

<p>This thesis consists of two parts. The first part analyzesthe accessibility, generation and license holding effects incar ownership models. The second part develops a route choicemodeling framework with an attempt to address the differencesin drivers' route choice behavior. These two parts of work areboth based on the discrete choice theory - the car ownershipmodels are built up on the standard logit model, whereas theroute choice models are formulated in a mixed logit form.</p><p>The study result of the first part shows that measuring theaccessibility by the monetary inclusive value reasonably wellcaptures the mechanism of the accessibility impact. Otheraccessibility proxies such as the parking costs, parking typeand house type are correlated with the accessibility but not toa great extent. Both young and old households are less likelyto have a car. The reduction of the propensity to own a car issignificant for households with average birth year before 1920,whereas this reduction is moderate for households with birthyear between 1920 and 1945. It is also demonstrated thatdriving license holding choice is conditional on the carownership level choice, and that these two choices need to bemodeled in a dynamic framework.</p><p>The second part of the work investigates the performance ofthe mixed logit model using both simulated data and empiricalroute switching data. The empirical study mainly focused on theimpacts of information and incident related factors on drivers'route switching behavior.</p><p>The result shows that using mixed logit gives a significantimprovement in model performance as well as a more sensitiveexplanation of drivers' decision-making behavior. For apopulation with greatly varying tastes, simply using thestandard logit model to analyze its behavior can yield veryunrealistic results. However, care must be taken when settingthe number of random draws for simulating the choiceprobability of the mixed logit model in order to get reliableestimates.</p><p>The empirical results demonstrate that incident relatedfactors such as delay and information reliability havesignificant impacts on drivers' route switching, where themagnitude of the response to the change in the delay is shownto vary significantly between individuals. Other factors, suchas confidence in the estimated delay, gender, frequency of cardriving and attitude towards congestion, also make majorcontributions. In addition, it is found that individual's routeswitching behavior may differ depending on the purpose of thetrip and when the choice is made, i.e. pre-trip oren-route.</p><p><b>Keywords</b>: car ownership, accessibility, logit model,route choice, heterogeneity, mixed logit model</p>