Browsing by Subject "Migration"

During the course of breast cancer progression, normally dormant tumor-promoting effects of transforming growth factor-beta (TGF-beta) including migration, invasion, and metastasis are unmasked. Although this switch or gain of TGF-beta function has been modeled extensively in in-vivo and in-vitro breast cancer systems, the signaling mechanisms that control this TGF-beta switch are poorly understood. Indeed, the precise role of canonical TGF-beta signaling through the type I TGF-beta receptor, ALK5, and its intracellular effectors, Smad2 and Smad3, is still poorly understood. In an effort to identify mechanisms that regulate the ability of TGF-beta to stimulate mammary epithelial cell migration in-vitro, we found that TGF-beta stimulates the phosphorylation of Smad1 and Smad5, intracellular effectors that are typically associated with bone morphogenetic protein (BMP) signaling. As this phosphorylation response has not been reported extensively, little is known about the prevalance, mechanism, function, or pathological relevance of TGF-beta-stimulated Smad1/5 phosphorylation.

Herein, we use pharmacologic inhibition, RNA interference, and additional biochemical and cell-based approaches to identify a novel mechanism and function for non-canonical TGF-beta signaling through an ALK5-Smad1/5 axis. We show that TGF-beta stimulates Smad1/5 phosphorylation in an ALK5 dependent manner in cells of epithelial, endothelial, and embryonic origin. Mechanistically, this phosphorylation event requires the kinase activity and, unexpectedly, the L45 loop motif of ALK5. Functionally, this phosphorylation event is essential to the initiation and promotion of TGF-beta-stimulated migration in mammary epithelial cells. Interestingly, this phosphorylation event may promote migration by regulating TGF-beta target gene expression, as evidenced by the identification of putative Smad1/5-dependent TGF-beta target genes using microarray analysis. Finally, of particular relevance to mammary tumor progression, this phosphorylation event is preferentially detected in permissive environments such as those created by tumorigenic cells or HER2 oncogene activation.

Taken together, our data provides evidence that TGF-beta-stimulated Smad1/5 phosphorylation, which occurs through a non-canonical mechanism that challenges the notion of selective Smad phosphorylation by ALK5, mediates the pro-migratory TGF-beta switch in mammary epithelial cells.

Border Images and Imaginaries: Spectral Aesthetics and Visual Media of Americanity at the U.S.-Mexico Border, proposes an emerging aesthetic of spectrality in visual media about the U.S.-Mexico border that challenges the power of militarized and racialized visibility. The visual media projects I work with, including cinema, electronic performance art, site specific video installation, and photography generate an aesthetic of spectrality as they try to conjure and express the socially invisible through sensual elements like affect, sound, kinaesthetics, and full embodiment. This aesthetic elicits the perceptions of our other senses beyond only the visual and makes visible the social flesh of the movements and socialities of migration rather than racialized, migrant bodies. The border, I claim, is an important site for understanding the continued deployment of visibility in the neoliberal legacies of what Quijano and Wallerstein call, Americanity, a term denoting the development of the modern capitalist system in the Americas which relied upon the imbricate logics of colonialism, racism, and the deification the modern. Images of spectrality are intermediaries between what Diana Taylor calls, archive and repertoire, being both documents and sites of embodied engagement that produce both certain and uncertain knowledges of race and migration at the border. The visual media projects in my dissertation cultivate spectral aesthetics to theorize an alternative visibility and the changing production of public memory. By making visible the social flesh of heterogeneous encounters with media, spectral aesthetics reforms collective memory making it a process of democratic editorialization that privileges experience as the site of a multivocal history. This project reclaims the image as a terrain for the multitude's inquiry and imagination about the US-Mexico border, and puts the imaginaries generated by these images in dialog with activist projects happening in relation to immigration.

People live and work in local markets spatially distinct from one another, yet space is absent from most economic models of the national labor market. Workers choose the markets in which they will participate, but there are costs to mobility. Furthermore, cities are heterogeneous in a number of dimensions, including their local labor market productivity, their housing supply, and their offering of amenities.

I examine the impact of these spatial considerations on the dynamics of local labor markets and the national market to which they aggregate. First I study the patterns of location choice through a gravity model of migration applied to rich panel data from the U.S. I find that location choices respond to temporal shocks to the labor market, but only after controlling for local heterogeneity. Next, with this result as motivation, I turn to development of a dynamic spatial equilibrium of the national labor market. I make a technical contribution to work in dynamic equilibrium modeling by empirically implementing an island economy model of worker mobility. I quantify the importance of worker mobility costs versus local housing prices for explaining spatial variation in the unemployment rate. I find that the link between the local housing market and the local labor market is important for explaining the spatial dispersion in unemployment, but mobility costs are not. Finally, I further exploit the dynamic equilibrium framework to examine the effect of local housing policy on labor market growth. I find that housing supply regulation is a constraint to growth, but is only binding on cities that are particularly desirable because of their labor market opportunities or amenities. I find that some lightly regulated markets have a contingent of population that has been pushed out of more regulated markets by high housing prices.

The ability of cells to migrate is of fundamental importance to a diverse array of biological processes, both physiological and pathological, such as development, the immune response and cancer cell metastasis, to name a few. The process of cell movement is a complicated cycle of coordinated steps involving dynamic and precise rearrangement of the actin-myosin cytoskeleton. As a critical component of the migration machinery, the molecular motor protein nonmuscle myosin II (myosin II) has long been a subject of scientific inquiry. It is now generally accepted that the contractile forces generated by myosin II contribute directly or indirectly to every step in migration. Interestingly, three isoforms of myosin II (myosin IIA, IIB and IIC) have been identified, and although each isoform performs the same basic molecular functions, recent findings suggest that the different myosin II isoforms make unique contributions to the motile process. In this dissertation work I used RNA interference technology to specifically deplete cells of myosin IIA and IIB in order to characterize the distinct migration phenotypes associated with loss-of-function of each individual isoform. Surprisingly, I found that the two myosin II isoforms perform not only distinct but opposing functions in cell migration, with myosin IIA and IIB normally inhibiting and facilitating proper cell movement, respectively. Furthermore, using pharmacological and microscopy techniques, I investigated the cellular mechanisms allowing for isoform-specific function. My results provide evidence for at least two isoform-specific regulatory mechanisms, namely selectivity in signaling pathways and subcellular distribution. A particularly significant finding is the identification of the different assembly properties of myosin IIA and IIB as the key element responsible for directing isoform-distinct distribution. Together the data presented herein represent a considerable advance in our understanding of the distinct functions and regulation of myosin II in cell motility.

This dissertation consists of three separate essays that use dynamic models to better understand the human capital accumulation process. First, I analyze the role of migration in human capital accumulation and how migration varies over the business cycle. An interesting trend in the data is that, over the period of the Great Recession, overall migration rates in the US remained close to their respective long-term trends. However, migration evolved differently by employment status: unemployed workers were more likely to migrate during the recession and employed workers less likely. To isolate mechanisms explaining this divergence, I estimate a dynamic, non-stationary search model of migration using a national longitudinal survey from 2004-2013. I focus on the role of employment frictions on migration decisions in addition to other explanations in the literature. My results show that a divergence in job offer and job destruction rates caused differing migration incentives by employment status. I also find that migration rates were muted because of the national scope of the Great Recession. Model simulations show that spatial unemployment insurance in the form of a moving subsidy can help workers move to more favorable markets.

In the second essay, my coauthors and I explore the role of information frictions in the acquisition of human capital. Specifically, we investigate the determinants of college attrition in a setting where individuals have imperfect information about their schooling ability and labor market productivity. We estimate a dynamic structural model of schooling and work decisions, where high school graduates choose a bundle of education and work combinations. We take into account the heterogeneity in schooling investments by distinguishing between two- and four-year colleges and graduate school, as well as science and non-science majors for four-year colleges. Individuals may also choose whether to work full-time, part-time, or not at all. A key feature of our approach is to account for correlated learning through college grades and wages, thus implying that individuals may leave or re-enter college as a result of the arrival of new information on their ability and/or productivity. We use our results to quantify the importance of informational frictions in explaining the observed school-to-work transitions and to examine sorting patterns.

In the third essay, my coauthors and I investigate the evolution over the last two decades in the wage returns to schooling and early work experience.

Using data from the 1979 and 1997 panels of the National Longitudinal Survey of Youth, we isolate changes in skill prices from changes in composition by estimating a dynamic model of schooling and work decisions. Importantly, this allows us to account for the endogenous nature of the changes in educational and accumulated work experience over this time period. We find an increase over this period in the returns to working in high school, but a decrease in the returns to working while in college. We also find an increase in the incidence of working in college, but that any detrimental impact of in-college work experience is offset by changes in other observable characteristics. Overall, our decomposition of the evolution in skill premia suggests that both price and composition effects play an important role. The role of unobserved ability is also important.

In this dissertation I study the long-term effects of post-disaster reconstruction of infrastructure on economic and demographic outcomes. The effects on individuals and communities that result from shocks to existing infrastructure have not been widely explored in the economic and development literature. As some of the largest natural disasters in recent times have shown, massive destruction of infrastructure is followed by large influxes of resources aimed at the reconstruction of damaged property. For example, after the 2004 Indian Ocean tsunami, Indonesia alone received enough aid to deal with the estimated seven billion dollars in infrastructure losses. While there are studies that address how money was allocated, there is hardly any good empirical evidence that provides a causal estimate of the effect that large reconstruction programs have on targeted beneficiaries. In this dissertation I address this gap in the literature.

The context of my study is the 2004 Indian Ocean tsunami, one of the most devastating natural disasters in recent years. In particular, the location for this analysis is the Indonesian province of Aceh, which was the area hardest hit by the disaster (Chapter 2). One of the main reasons why long-term impacts of post-disaster reconstruction remain an understudied topic is the lack of access to data that tracks individuals over time and across space. Having longitudinal data of this type provides a more complete picture of beneficiaries of post-disaster aid, as well as the effects of reconstruction programs on economic outcomes and demographic processes, such as migration. My dissertation addresses this concern by using a unique, population representative panel of survivors of the Indian Ocean tsunami, the Study of the Tsunami Aftermath and Recovery (STAR), which collected extensive individual, household, and community data in Aceh, Indonesia, every year between 2005 and 2010, with an additional follow-up in 2015 (Chapter 3).

Using these data, the first question I explore empirically is an estimation of the causal effects of reconstruction of the housing stock on a multidimensional set of well-being measures (Chapter 4). First, I show that post-tsunami reconstruction was largely determined by the level of damage, regardless of pre-tsunami characteristics of communities, households, and individuals. Based on this finding, I identify the causal effects of housing reconstruction on post-disaster well-being using an individual fixed effects strategy. I show that housing reconstruction causes significant reductions in levels of post-traumatic stress reactivity, and significant increases in socioeconomic well-being. These effects are mainly concentrated after two years of housing tenure, and among those from highly damaged communities. Housing reconstruction has a positive relationship with self-rated physical health (although these estimates are not statistically significant). These results provide important causal evidence of how reconstruction of infrastructure after a natural disaster can have long-lasting, positive consequences for the recovery of survivors.

Next, I continue looking at the effects of rebuilding individual assets (i.e. the home) but turn to the analysis of migration, a key demographic process following natural disasters. Specifically, I look at migration and its relationship with housing reconstruction and well-being (Chapter 5). The 2004 Indian Ocean tsunami displaced large numbers of people. In Aceh, Indonesia, an estimated 500,000 people left their communities after the disaster. In this research, we provide a demographic perspective on displacement and longer-term adaptation and recovery after a disaster. We describe patterns of mobility among tsunami survivors, including those who did not return to their origin communities, those who did return, and those who never left. We also consider mobility among those living in communities that did not suffer tsunami damage. We then examine how the likelihood of receiving housing aid varies across these subgroups. Finally, we consider how measures of subjective well-being evolve after the disaster. Results show that predictors of relocation vary significantly across individuals depending on the level of exposure of communities to the physical damage of the tsunami. Relocation decisions, and in particular staying in the pre-tsunami community, are highly related to the likelihood of benefiting from housing aid. And, changes in subjective well-being not only depend on receipt of housing aid but also on interactions between relocation decisions.

The last empirical analysis changes the focus from the reconstruction of individual assets to the reconstruction of community infrastructure (Chapter 6}), an important component of post-disaster rebuilding programs. In the aftermath of the tsunami, it is estimated that a total of 2,600 km of roads and 119 bridges needed rebuilding. In less than four years a total of 3,700 km of roads and all the destroyed (or damaged) bridges had been rebuilt \citep{indonesia2010provincial}. Roads can be an important gateway to economic development, so in this analysis I focus on estimating the economic effects of road reconstruction in post-tsunami Aceh. First, I exploit variation in timing of road reconstruction projects at the community level and, using a fixed effects strategy, I show that road reconstruction may not be enough to cause significant economic effects, but that quality of road construction matters, specifically access to all-weather roads. Further, I also show that road reconstruction that happens in combination with public works programs has additional positive effects. I provide further evidence on the effects of road reconstruction by looking at the specific case of the reconstruction of the Banda Aceh-Meulaboh road. The Banda Aceh-Meulaboh road is a good example of a project that seeks to restore large public infrastructure after a major shock to the built environment under the assumption that it would contribute to restore economic activity in the area. Using a difference-in-differences strategy, I exploit changes in access to the road between 2005 and 2015. I show that gaining access to the road has positive and modest effects both on individuals and households and, in particular, on households in rural areas. I did not find any statistically significant negative effects of losing access to the road but results from this case study point that losing access may be hindering some progress, for example, to translate work opportunities into higher wages.

Taken together, results from the empirical analyses in this dissertation fill an important gap in our understanding of what happens to disaster victims in the long-run, how they benefit from reconstruction programs that rebuild both individual and community assets, and how these programs can have long-lasting consequences on economics and demographic trajectories of populations. As a result, my study not only represents an important contribution to existing literature, but it also underscores the importance of having data collection projects that account for the long-term nature of infrastructure reconstruction projects. Natural disasters are projected to become increasingly more common, and this type of data can result in empirical research, like this dissertation, that can improve our understanding of how disaster victims cope, which strategies work best and why, and create lessons that can inform disaster management and reconstruction policies that will result in successful post-disaster experiences.

The histologic subtypes of malignant glial neoplasms range from anaplastic astrocytoma to the most deadly World Health Organization (WHO) Grade IV glioblastoma (GBM), the most common primary brain tumor in adults. Over the past 40 years, only modest advancements in the treatment of GBM tumors have been reached. Current therapies are predominantly for palliative endpoints rather than curative, although some treatment modalities have been shown to extend survival in particular cases. Patients undergoing current standard of care therapy, including surgical resection, radiation therapy, and chemotherapy, have a median survival of 12-15 months, with less than 25% of patients surviving up to two years and fewer than 10% surviving up to five years. A variety of factors contribute to standard treatment failure, including highly invasive tumor grade at the time of diagnosis, the intrinsic resistance of glioma cells to radiation therapy, the frequent impracticality of maximal tumor resection of eloquent cortical structures, and the fragile intolerance of healthy brain for cytotoxic therapies. Treatment with immunotherapy is a potential answer to the aforementioned problems, as the immune system can be harnessed and educated to license rather potent antitumor responses in a highly specific and safe fashion. One of the most promising vehicles for immunotherapy is the use of dendritic cells, which are professional antigen-presenting cells that are highly effective in the processing of foreign antigens and the education of soon-to-be activated T cells against established tumors. The work outlined in this dissertation encompasses the potential of dendritic cell therapy, the current limitations of reaching full efficacy with this platform, and the recent efforts employed to overcome such barriers. This work spans the characterization and preclinical testing of utilizing protein antigens such as tetanus-diphtheria toxoid to pre-condition the injection site prior to dendritic cell vaccination against established tumors expressing tumor-specific antigens.

Chapter 1 comprises an overview of the current standard therapies for malignant brain tumors. Chapters 2 and 3 provide a review of immunotherapy for malignant gliomas in the setting of preclinical animal models and discuss issues relevant to the efficacy of dendritic cell vaccines for targeting of GBM. Chapters 4 provides the rationale, methodology, and results of research to improve the lymph node homing and immunogenicity of tumor antigen-specific dendritic cell vaccines in mouse models and in patients with newly diagnosed GBM. Chapter 5 delineates the interactions discovered through efforts in Chapter 4 that comprise protein antigen-specific CD4+ T cell responses to induced chemokines and how these interactions result in increased dendritic cell migration and antitumor responses. Lastly, Chapter 6 discusses the future utility of migration of DC vaccines as a surrogate for antitumor responses and clinical outcomes.

This dissertation comprises original research as well as figures and illustrations from previously published material used to exemplify distinct concepts in immunotherapy for cancer. These published examples were reproduced with permission in accordance with journal and publisher policies described in the Appendix.

In summary, this work 1) identifies inefficient lymph node homing of peripherally administered dendritic cells as one of the glaring barriers to effective dendritic cell immunotherapy, 2) provides answers to overcome this limitation with the use of readily available pre-conditioning recall antigens, 3) has opened up a new line of investigation for interaction between recall responses and host chemokines to activate immune responses against a separate antigen, and 4) provides future prospects of utilizing chemokines as adjuvants for additional immunotherapies targeting aggressive tumors. Together, these studies hold great promise to improve the responses in patients with GBM.

Between 2015 and 2019, approximately 1.8 million Venezuelans fled into neighboring Colombia, increasing Colombia’s population by almost 4%. In this dissertation, I study the effects of this large and unprecedented migration wave on Colombian labor market outcomes and attitudes towards foreigners. In Chapter 1, I study the economic effects of the migration using variation in the migration rate across 79 metropolitan areas, labor survey data, and an instrumental variable strategy based on historical migration rates. I find that Venezuelan migration caused a moderate decrease in the hourly wages of native Colombians that is most concentrated among low-wage and informal workers. Existing studies of this migration wave using similar methods and data have estimated different magnitudes for this wage effect, and I demonstrate the differences in specification that drive these discrepancies. In Chapter 2, I study the consequences of migrant occupational downgrading by estimating an aggregate production function that incorporates imperfect substitutability between migrants and natives and migrant occupational downgrading. I find that downgrading concentrates economic competition among less educated natives and decreases output in both the short- and long-term, thus affecting both wage equality and productivity. In Chapter 3, I study the effect of migration on trust towards foreigners using a nationwide survey on social preferences. While migration has no effect on trust on average, the effect is positive in municipalities that are more urbanized, have greater access to high-quality public goods, and where there is more residential integration between migrants and natives.

My dissertation, Fascist Fiction: Inventing the Lesser Evil in Italy and Brazil, accounts for the resilience of fascism by tracing the rhetoric of the “lesser evil”—a discursive practice constitutive of fascism—through contemporary politics and literature in Italy and Brazil. By invoking the looming presence of a graver, more insidious threat the rhetoric of the lesser evil legitimizes fascist violence against dissidents and vulnerable populations. Through an analysis of texts by fascist philosopher Giovanni Gentile and his Brazilian counterpart Miguel Reale, I reveal that the rhetoric of the lesser evil is a constitutive part of fascist discourse and that in Italy and Brazil this aspect of fascist doctrine met a favorable combination of subjective and objective conditions which has allowed it to thrive within democratic structures. Finally, I argue that when moral claims such as the lesser evil work to obfuscate the understanding of traumatic and violent events within the public sphere, novels––precisely because of their putative fictionality––can offer persuasive counter-histories that re-contextualize fascist crimes and sometimes provoke acts of reparative justice by the State. My dissertation advances scholarship on the transcultural reach of fascist ideology: it contributes to an understanding of fascism’s place within a broader tradition of right-wing thought that continues to shape present-day politics in Europe and the world, and enriches our perception of the powers of literary forms.

This dissertation explores the meaning and importance of migration and home for the Christian Life in the context of modernity and the colonial history of the Americas. In doing so, it offers a constructive theological proposal that addresses two interrelated questions. First, what does a truly flourishing human life look like in view of the realities of migration and home? That is to say, how are migration and home aspects of God's created order that are deformed by human sinfulness yet still caught up in the eschatological renewal of all things? Second, can Christianity, despite its role in the colonization of the Americas, offer a vision of migration and home that leads to the flourishing of all creatures? This dissertation addresses these questions by locating the realities and experiences of migration and home within the Triune drama of God's creative, reconciling, and redemptive work as enacted within the story of the Americas—its peoples, lands, and cultures, from the moment of colonization up to our current modern moment.This study makes a methodological contribution to the fields of Reformed and Latinx theology by engaging in a mode of ressourcement from the margins. In dialogue with the works of Karl Barth, George Tinker, Willie Jennings, and Latinx theologians, like Virgilio Elizondo and Ada María Isasi-Díaz, I demonstrate how Christianity's eschatological vision of all creation joined together in Christ by the Spirit provides an alternative to a colonial and modern vision of home grounded in the commodification of the land, the destruction of native cultures, and the segregation of peoples into racial and national enclosures. Moreover, I argue that the Virgin's appearance to Juan Diego at Tepeyac, Mexico in 1531 summons the Church to look for God's redemptive homecoming at the margins of society where the political, economic, and socio-cultural negotiations that displaced peoples make in order to make a home in the world become the site of the Spirit's reconciling and redeeming work in creation. The final chapter provides a theological account of what sociologist Paolo Boccagni describes as the "migration-home nexus" by arguing that a flourishing human life takes place at the nexus of migration and home and the forms of political, economic, and cultural negotiations and mestizaje that this nexus produces. I argue that through these, the Spirit works to transform creation into the eternal home of God. I conclude by drawing on the notion of ‘transplantation’ to describe wise ways of migrating and homing in anticipation of the Triune God's redemptive homecoming.

This dissertation explores the place of Irish-Gaelic language (Gaeilge) television and film media in the lives of youths living in the urban greater Dublin metropolitan area in the Republic of Ireland. By many accounts, there has been a Gaeilge renaissance underway in recent times. The number of Gaeilge-medium primary and secondary schools (Gaelscoileanna) has grown throughout the 1990s and into the twenty-first century, the year 2003 saw the passage of the Official Languages Act (laying the groundwork to assure all public services would be made available in Gaeilge as well as English), and as of January 2007 Gaeilge has become a working language of the European Union. Importantly, a Gaeilge television station (TG4) was established in 1996. This development has increased the amount of Gaeilge media significantly, and that television and film media is increasingly being utilized in Gaeilge classrooms.

The research for this dissertation was based on a year of fieldwork conducted in Dublin, Ireland. The primary methodology was semi-structured interviews with teenage second-level-school students who were enrolled in compulsory Gaeilge classes at two schools in the greater Dublin area. Simultaneous examination of social discourses, in the form of prevalent television and film media, and the talk of the teenage students I interviewed led me to discern a "locality production" process that can be discerned in both these forms of discourse. While it is noted that this process of locality production may be present anywhere, it is suggested that it may be particularly pronounced in Ireland as a result of a traditional emphasis on "place" on the island.

This dissertation thus makes a contribution to Irish and Media Studies through an analysis of Gaeilge cultural productions in the context of increased effects of globalization on the lives of the youth with whom I did my research. Additionally, this dissertation contributes to an on-going critique of identity-based theorizations through contribution of an alternative framework.

Tens of thousands of migrant domestic workers, women working and residing within Kuwaiti households, have taken shehadeh, the Islamic testament of faith over the past decade. Drawing on 21 months of ethnographic fieldwork in Kuwait, and 2 months of research in Nepal, this dissertation analyzes the processes through which South Asian domestic workers develop newfound Islamic pieties, processes that underscore the importance of the household as a site of intersection between transnational migration and globalizing Islamic movements, and that point to the limitation of conventional understandings of wage labour and religious conversion.

In the first chapter of this dissertation, I outline a hedonic equilibrium model that explicitly controls for moving costs and forward-looking behavior. Hedonic equilibrium models allow researchers to recover willingness to pay for spatially delineated amenities by using the notion that individuals "vote with their feet." However, the hedonic literature and, more recently, the estimable Tiebout sorting model literature, has largely ignored both the costs associated with migration (financial and psychological), as well as the forward-looking behavior that individuals exercise in making location decisions. Each of these omissions could lead to biased estimates of willingness to pay. Building upon dynamic migration models from the labor literature, I estimate a fully dynamic model of individual migration at the national level. By employing a two-step estimation routine, I avoid the computational burden associated with the full recursive solution and can then include a richly-specified, realistic state space. With this model, I am able to perform non-market valuation exercises and learn about the spatial determinants of labor market outcomes in a dynamic setting. Including dynamics has a significant positive impact on the estimates of willingness to pay for air quality. In addition, I find that location-specific amenity values can explain important trends in observed migration patterns in the United States.

The second chapter of this dissertation describes a model which estimates willingness to pay for air quality using property value hedonics techniques. Since Rosen's seminal 1974 paper, property value hedonics has become commonplace in the non-market valuation of environmental amenities, despite a number of well-known methodological problems. In particular, recovery of the marginal willingness to pay function suffers from important endogeneity biases that are difficult to correct with instrumental variables procedures [Epple (1987)]. Bajari and Benkard (2005) propose a "preference inversion" procedure for recovering heterogeneous measures of marginal willingness to pay that avoids these problems. However, using cross-sectional data, their approach imposes unrealistic constraints on the elasticity of marginal willingness to pay. Following Bajari and Benkard's suggestion, I show how data describing repeat purchase decisions by individual home buyers can be used to relax these constraints. Using data on ozone pollution in the Bay Area of California, I find that endogeneity bias and flexibility in the shape of the marginal willingness to pay function are both important.

Finally, in the third chapter of this dissertation, I combine the insights of the Bajari-Benkard inversion approach employed in second chapter with more standard estimation techniques (i.e., Rosen (1974)) to arrive at a new hedonic methodology that allows for flexible and heterogeneous preferences while avoiding the endogeneity problems that plague the traditional Rosen two-stage model. Implementing this estimator using the Bay Area ozone data, I again find evidence of considerable heterogeneity and of endogeneity bias. In particular, I find that a one unit deterioration in air quality (measured in days in which ozone levels exceed the state standards) raises marginal willingness to pay by $145.18 per year. The canonical two-stage Rosen model finds, counter-intuitively, that this same change would reduce marginal willingness to pay by $94.24.

Political upheaval in Syria makes Jordan a temporary home to over one million Syrian refugees. More than half of these individuals, due to limited resources and challenging financial circumstances, do not have adequate access to reproductive health and family planning mechanisms. Among pregnant refugee women in Jordan, approximately one in five are at risk for poor obstetrical outcomes, including premature and underweight births. Due to increased rates of birth in humanitarian and lower resource settings, and the crucial need for addressing sexual and reproductive health in these settings, this study conducted a comparative analysis of the sexual and reproductive health climate among Syrian refugee and Jordanian men and women.

Using a case study research design, semi-structured qualitative interviews were conducted with 34 study participants, including 15 Syrian women, 8 Jordanian women, 6 Syrian men, and 5 Jordanian men. These interviews examined participants’ migration experiences, pregnancy outcomes, influencers for reproductive decisions, and gaps in sexual and reproductive health care.

Qualitative interviews revealed that Syrian refugees indicated greater reproductive and sexual health need than Jordanians, more specifically related to education on reproductive health and contraceptive methods. Syrian refugees were married at earlier ages than Jordanians, and, overall, had more children. Additionally, Syrian refugees confirmed that healthcare in Syria was more accessible, affordable, and comprehensive in comparison to Jordan. The greatest contributors to gaps in care for both Jordanians and Syrians were financial constraints and apathy regarding refugee welfare among providers in public facilities.

Increasing access to comprehensive sexual and reproductive healthcare among refugees in low-resourced, humanitarian settings, while also continuing to meet the needs of the nation’s own population, is a healthcare priority. The findings of this study have the potential to guide and influence policy affecting family planning mechanisms afforded to migrants in Jordan in both public and private facilities. Action is required immediately by policymakers and government officials to create budgetary resources for sexual and reproductive health education programs in Jordan in order to meet the family planning needs of refugee and migrant populations residing there.

Background: Plasmodium vivax and Plasmodium falciparum contribute a high burden of disease in the Peruvian Amazon. Migration is an important risk factor for malaria, as travel along the river systems accounts for the vast majority of movement within this region. This travel creates networks of transmission that allows individuals who travel to contract malaria as well as generating transmission across communities by repeatedly reintroducing the parasite into different areas, which can complicate control efforts.

Methods: Surveyors visited homes of participants three times a week to carry out active surveillance between July 2006 and October 2009. For participants returning from travel, data were collected on destination and duration away, which was used to define a typology for migrant populations. Incidence rates of malaria and migration typology characteristics were assessed through Negative Binomial regression models and migration rates with hydrological factors by logistic regression models.

Results: A cohort of 2,202 participants from 402 families were followed for three years and categorized by the average number of annual trips taken. High-frequency and low-frequency migrant populations reported 9.7 (IRR 7.59 (95% CI:.381, 13.160)) and 4.1 (IRR 2.89 (95% CI: 1.636, 5.099)) times more P. vivax cases than those considered non-migrants and 30.7 (IRR 32.42, (95% CI: 7.977, 131.765)) and 7.4 (IRR 7.44 (95% CI: 1.783, 31.066)) times more P. falciparum cases, respectively. Among high frequency migrants, males were at a 1.20 (95% CI: 0.872, 1.641) increased risk compared to female high frequency migrants. Working in agriculture, logging, and fishing were at 1.02, 1.36, 1.93 increased risk for P. vivax and 2.46, 2.35, 2.03 times increased risk of P. falciparum compared to those in non-migrant positions. However, the greatest occupation related risk was attributed to high frequency migrants employed in manual labor within their community. This group was at 2.45 (95% CI: 1.113, 5.416) times higher risk than non-employed low frequency migrants. Travel to lakes, rivers, and streams were 2.36, 1.81, and 1.95 times as many P. vivax and 1.36, 1.34, and 2.08 P. falciparum cases, respectively, compared to travel to communities. More migration episodes were recorded in the dry season, however, the seven day rolling mean streamflow was positively correlated with migration events (OR 1.25 (95% CI: 1.138, 1.368)).

Conclusions: Migration is a key risk factor for malaria; however, it alone does not characterize the distribution on risk within the migrant community. This study gives information about particular population groups to target control efforts.