This dissertation looks at three aspects of inequality within labor markets: wage inequality, intergenerational economic mobility, and inequality in higher education between sexes. The first chapter examines the contribution of offshoring to the relative decline in the wages paid to middle skilled workers. Within a task based model of production, I develop a theoretical framework that demonstrates how increased offshoring is consistent with a decline in domestic employment and a reduction in the wages paid to workers in middle skilled occupations. I test these predictions empirically using a proxy measure of offshoring. I find that industries which engage in offshoring see their domestic employment decline over time and have a wider gap between the wages of their middle and high skilled workers. Current levels of industry offshoring are significantly correlated with an industry's lagged occupational composition. Both material and service offshoring decrease with the share of manual occupations and service offshoring increases with the share of routine occupations. Chapter two estimates the magnitude of the intergenerational elasticity of income found in the NLSY79, and provides a decomposition of this elasticity into paternal and maternal effects. Roughly one fourth of intergenerational income transmission can be attributed to maternal earnings, and omitting maternal income biases the estimate of the effect of paternal income by over 20 percent. The third chapter analyzes the growing inequality in college graduation rates between men and women. Evidence from two cohorts in the National Longitudinal Surveys suggests that although women have performed better in high school than men for several decades, the impact of high school performance on college success has increased dramatically since the 1980s. The increasing weight attributed to academic excellence in high school explains a substantial portion of the female advantage in college graduation over their male peers.

Boston University. University Professors Program Senior theses. / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-02

Thesis (Ph.D.)--Boston University / The purpose of the present study is to investigate the relationship between patental social mobility and (a) subjects' status aspirations, (b) perceived parental status expectations. The subject population utilized consisted of 263 male students in the final year of junior high school. Two major hypotheses were tested by this investigation. Hypothesis I was that the level of subjects' status aspirations would be found to be a positive monotonic function of the extent of parental social mobility. Hypothesis II was that the level of perceived parental status expectations would be found to be a positive monotonic function of the extent of parental social mobility. [TRUNCATED]

La mobilité joue un grand rôle à Niamey, où le besoin de déplacement des habitants croît avec l'étalement continu de la ville. Les habitants de Niamey sont de ce fait contraints de se déplacer pour des raisons professionnelles, d'achats ou des loisirs, etc. Soumise à une croissance démographique soutenue et son corollaire un étalement spatial continu Niamey est caractérisée par la concentration des services, équipements et commerces dans le centre ville et une périphérie dortoir. Cette distribution de fonction entraine une augmentation des distances entre le lieu d'habitation et les zones administratives et commerciales sises au cœur de la ville posant de sérieux problèmes de transport urbain du fait de la faiblesse de l'offre des services, la vétusté des infrastructures et le difficile accès aux moyens de transport sont des problèmes récurrents pour les populations. Parmi les catégories le moins mobiles, il y a les pauvres, femmes, les personnes âgées, etc. Les habitants des quartiers périphériques sont les plus défavorisés : ils se déplacent peu et sont donc faiblement intégrer à l'ensemble de la ville. Le tarif de la course élément fondamental du coût de déplacement influence beaucoup le choix de tel ou tel moyen de transport (taxi tête rouge, faba-faba, bus de la SOTRUNI) selon le pouvoir d'achat du client. Se déplacer dans de bonnes conditions, par nécessité ou par convenance, est pour chaque citoyen un aspect essentiel de la vie quotidienne. C'est aussi une des clés de l'urbanité et de la performance des agglomérations. La question des déplacements urbains est donc au cœur de la gestion politique des villes. / Mobility plays an important role in Niamey , where the need for movement of people increases with the continuous urban sprawl . The people of Niamey are therefore forced to move for business reasons shopping , or recreation. Subject to population growth and its corollary a continuous urban sprawl Niamey is characterized by the concentration of services, facilities and shops in the city center and a periphery dormitory. This distribution function leads to an increase of the distance between the place of residence and the administrative and commercial areas lying to the heart of the city posing serious urban transport problems due to the lack of supply of services, poor infrastructure and poor access to transport are recurring problems for people . Among the less mobile groups , there are the poor, women, elderly, etc. . The inhabitants of the suburbs are the most disadvantaged : they move little and are weakly integrated into the whole city . The rate of the fundamental race travel cost greatly influence the choice of a particular mode of transport (red taxi head - faba faba bus SOTRUNI ) according to the purchasing power of the customer. Move in the right conditions, by necessity or convenience , every citizen is an essential part of everyday life. It is also a key to the urbanity and performance areas. The issue of urban mobility is at the heart of the political management of cities.

A growing body of research suggests that intra-organizational mobility represents an important source of value creation and retention. Internal hires who are embedded in organizational social networks have greater resources and experience than external workers who are less socially connected. Notwithstanding the great practical and theoretical interest in the benefits of intra-organizational mobility at the organizational level, little is known about how individuals’ intra-organizational careers unfold and the influence of social networks toward that end. This dissertation combines findings from three separate projects to investigate the mechanisms underlying the phenomenon of intra-organizational mobility—the structural factors that explain why people move within an organization, how movers and incumbents do or do not benefit from mobility, and the individual differences in network behavior for mobility. More specifically, in the first chapter, I examine how pre-existing communication contacts affect the mover’s performance upon joining the new group. I expect that movers are more likely to join business units to which they have pre-existing ties. Nonetheless, the ties that facilitate movers’ joining business units are oftentimes not those that help them to perform well subsequently. In the next chapter, I explore gender differences in network behavior as they impact on intra-organizational mobility. I argue that when a mover retains ties to the working unit that is being left, it improves the mover’s post-move performance. And women are more likely to maintain such persistent social ties, whereas men are more likely to establish new ties. In the final chapter, I assess the effects on the receiving group when a mover joins, and I argue that low-ranking incumbents embedded in stable performance hierarchies suffer from the introduction of high-performing newcomers and the induced unfavorable social comparison. I test my predictions using time-series data on the internal inter-branch transfers of retail sales employees at a US-based financial institution between November 2014 and April 2016. The dataset is composed of individual demographic information, monthly performance metrics (in dollars), and meta email communication among all employees. The data permits several methodological advancements: (1) the use of objective and consistent performance measures; (2) analysis of the temporal changes in the networks of the movers and their contacts; (3) analysis of communication network and its impact on performance, and (4) robustness checks that apply instrumental variable techniques. The approach taken in this dissertation adds a new perspective on the relationship between intra-organizational mobility and competitive advantage.

Neste trabalho apresentamos medidas de fotocondutividade, decaimento da fotocondutividade persistente, resistência em função da temperatura em amostras de AlxGa1-xAs de gap direto e indireto, dopadas com Si. Comparamos as teorias de Brooks-Herring e Takimoto, ambas referentes ao espalhamento por impurezas ionizadas, e sua aplicabilidade para nosso material. Interpretamos a presença de um estado de energia intermediário nos cálculos da energia de ativação baseado nos resultados de concentração de elétrons livres em função da temperatura .como devido ao defeito D-. Nos resultados de decaimento da fotocondutividade persistente no intervalo de 80 - 100K, contamos com a contribuição do espalhamento por dipolos e propomos o par d+ - VAS- como os responsáveis pela formação destes dipolos e conseqüente melhoria do ajuste da simulação numérica. / In this work, we show results of photoconductivity, decay of persistent photoconductivity, resistance x temperature in Si doped direct and indirect bandgap AlxGa1-xAs. We compare Brooks-Herring and Takimoto theories, both in reference to ionized impurity scattering applied to our material. We interpret the intermediate state in our calculation of activation energy as a D- defect. In the numerical simulation of decay of persistent photoconductivity in the range 80-100 K, we propose the dipole pair d+ - VAS- responsible for the fitting improvement, when the dipole scattering is taken into account.

Submitted by Luiz Felipe Barbosa (luiz.fbabreu2@ufpe.br) on 2015-03-10T19:41:00Z No. of bitstreams: 2 DISSERTAÇÃO Vinicius Cezar Monteiro de Lira.pdf: 4006584 bytes, checksum: 5d1301329fabe34879780b3b17bb1e8a (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Approved for entry into archive by Daniella Sodre (daniella.sodre@ufpe.br) on 2015-03-10T19:43:51Z (GMT) No. of bitstreams: 2 DISSERTAÇÃO Vinicius Cezar Monteiro de Lira.pdf: 4006584 bytes, checksum: 5d1301329fabe34879780b3b17bb1e8a (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-10T19:43:51Z (GMT). No. of bitstreams: 2 DISSERTAÇÃO Vinicius Cezar Monteiro de Lira.pdf: 4006584 bytes, checksum: 5d1301329fabe34879780b3b17bb1e8a (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2014-08-28 / The analysis of human movements has been the subject of several studies since the 70s. In recent years, the exponential growth of location aware devices must allow the study of the behavior of the individuals’ mobility from their trajectories collected. However, a significant part of the available literature is focused on the development of techniques for analyzing trajectories of people from a purely geometric point of view, while a smaller part, but increasingly group is looking at the semantic aspects of mobility. This work presents a contribution to the latest trend, and is concerned with the definition of semantic regularity profiles and the applicability of these concepts to the practice of carpooling. We propose a semantic regularity profile based on the entropy of the spatial and temporal frequency of visits to certain categories of places. We analyze the user’s behavior with respect to regularity and irregularity, identifying users who are more or less loyal to certain locations, in contrast to the irregularity of visiting different places. In a different point of view, an analysis over the place perspective was also performed. A web tool was developed to show on map, for each place of a given category, the computed information about the loyal behavior of their visitors. From the study about regularity, we have evidences that some human activities are not strictly associated to a unique POI (Point of Interest) and neither to a specific schedule of the day. Bringing to the carpooling context, in some situations it is worth for a person to change his destination or the time to perform an activity if there is a possibility of ride for him due all the benefits involved with the carpooling practice. This dissertation also presents a novel matching method for carpooling that is oriented to the passenger’s intended activity, aiming to boost the possibilities of rides. Three algorithms for carpool matching are proposed, which manipulates differently the spatial and temporal dimensions. Using a real data set of trajectories, we conducted experiments and our results showed that the proposed matching algorithms improved the traditional carpooling approach in +46.84% when the spatial dimension was considered, in +50.89% when the temporal dimension was prioritized and in +82.30% when both dimensions were tackled.

The explosion of personal positioning devices like GPS-enabled smartphones has enabled the collection and storage of a huge amount of positioning data in the form of trajectories. Thereby, trajectory data have brought many research challenges in the process of recovery, storage and knowledge discovery in mobility as well as new applications to support our society in mobility terms. Other research area that has been receiving great attention nowadays is the area of complex network or science of networks. Complex network is the first approach to model complex system that are present in the real world, such as economic markets, the Internet, World Wide Web and disease spreading to name a few. It has been applied in different field, like Computer Science, Biology and Physics. Therefore, complex networks have demonstrated a great potential to investigate the behavior of complex systems through their entities and the relationships that exist among them. The present dissertation, therefore, aims at exploiting approaches to analyze mobility data using a perspective of complex networks. The first exploited approach stands for the trajectories as the main entities of the networks connecting each other through a similarity function. The second, in turn, focuses on points of interest that are visited by people, which perform some activities in these points. In addition, this dissertation also exploits the proposed methodologies in order to develop a software tool to support users in mobility analysis using complex network techniques.

Inequities in education have long been the driving force behind school reform movements. In efforts to desegregate schools and offer more equitable education opportunities, more privatized and marketized school systems have emerged. This movement has been referred to as neoliberalism. This term encompasses the individual’s right to make school selections based on their personal preferences or desires. Current school choice research suggests parents seek schools with better resources or curriculum, desire the social connections certain schools can offer them, or select schools based on right fit for their families. Neoliberals argue that schools will be reformed or transformed as a result of changing to meet the needs of their customers. They believe competitive school markets will lead to better education systems. However, outcomes of choice movements have been inconsistent and have not demonstrated that choice has impacted achievement or addressed educational disparities. Some argue that it has further segregated schools and has led to greater inequities, particularly for minority or disadvantaged students. Furthermore, the research suggests that access may be facilitated or hindered by an individual’s cultural or social capital. Conversely, the research on student mobility suggests that minority and disadvantaged student populations are often highly mobile students. Frequent school moves for these student groups are detrimental to their academic success and can affect their school experience on multiple levels. The result is two opposing views on how to best ensure student achievement. One view encourages movement, the other does not. This study examined the use of open-enrollment in highly-mobile, high poverty schools. The findings suggest that a connection between student mobility and use of open-enrollment exists. Additionally, the findings revealed that barriers continue to hinder true choice access and motivations for school choice differs in parents at high-poverty, high-mobility schools. The parents in this study did not exercise choice to improve academic outcomes. This is counter to the intent of school choice. Factors such as safety, happiness and relationships were more valued and sought. Moreover, school movement was often prompted by negative events resulting in situational movement. In these instances, open enrollment was utilized to facilitate a reactionary response instead of being utilized to improve achievement outcomes. Based on the results of this study, an evaluation of current school choice practices, legislation and funding may be necessary to ensure the future success of students when exercising choice opportunities.

This thesis examines issues surrounding route navigation. Emphasis is on the problems of elderly motorists. Elderly drivers have been said to avoid unfamiliar routes and may have wayfinding problems, but the extent and nature of these problems have not previously been investigated. This thesis aims to determine how drivers plan their routes and find their way in transit. It also seeks to investigate the prevalence and types of driver wayfinding problems, as well as their causes, consequences and psychological implications. Lastly, this thesis aims to measure the impact wayfinding problems have on mobility and identify potential solutions. Three studies were conducted, the first was a preliminary investigation into route navigation issues. Focus group discussions explored driver wayfinding strategies and problems. The second study consisted of a postal questionnaire survey of motorists. Results suggested the most common route planning method was to read a map and take notes of the route. For wayfinding on major roads, drivers stated a preference for road number, place name, and junction information. In cities, they requested information about street names, lane position and landmarks. More drivers under 60 years of age preferred landmark information than did elderly drivers. The most frequent wayfinding errors were: missing a road sign, choosing the wrong lane, and detecting a sign or a turn too late to respond safely. The most frequently reported causes of wayfinding errors were: insufficient, inaccurate, obscured or non-existent traffic signs; inattention or distraction; inaccurate directions; darkness; busy roads and road repairs. As hypothesised, elderly drivers reported more difficulties with wayfinding and this was related to reduced mobility. The third study explored different means of presenting route guidance information. An experiment was conducted to investigate the safety and efficiency of visual, auditory (speech) or a combined visual-auditory display. Driver performance, visual behaviour, subjective mental workload and preferences were recorded. For displaying simple route guidance information to drivers across ages, it is recommended that verbal displays be used as a primary source of guidance information and visual displays as a redundant reminder.