College of Behavioral & Social Sciences
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The collections in this community comprise faculty research works, as well as graduate theses and dissertations..
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Item Potential Transient Response of Terrestrial Vegetation and Carbon in Northern North America from Climate Change(MDPI, 2019-09-18) Flanagan, Steven A.; Hurtt, George C.; Fisk, Justin P.; Sahajpal, Ritvik; Zhao, Maosheng; Dubayah, Ralph; Hansen, Matthew C.; Sullivan, Joe H.; Collatz, G. JamesTerrestrial ecosystems and their vegetation are linked to climate. With the potential of accelerated climate change from anthropogenic forcing, there is a need to further evaluate the transient response of ecosystems, their vegetation, and their influence on the carbon balance, to this change. The equilibrium response of ecosystems to climate change has been estimated in previous studies in global domains. However, research on the transient response of terrestrial vegetation to climate change is often limited to domains at the sub-continent scale. Estimation of the transient response of vegetation requires the use of mechanistic models to predict the consequences of competition, dispersal, landscape heterogeneity, disturbance, and other factors, where it becomes computationally prohibitive at scales larger than sub-continental. Here, we used a pseudo-spatial ecosystem model with a vegetation migration sub-model that reduced computational intensity and predicted the transient response of vegetation and carbon to climate change in northern North America. The ecosystem model was first run with a current climatology at half-degree resolution for 1000 years to establish current vegetation and carbon distribution. From that distribution, climate was changed to a future climatology and the ecosystem model run for an additional 2000 simulation years. A model experimental design with different combinations of vegetation dispersal rates, dispersal modes, and disturbance rates produced 18 potential change scenarios. Results indicated that potential redistribution of terrestrial vegetation from climate change was strongly impacted by dispersal rates, moderately affected by disturbance rates, and marginally impacted by dispersal mode. For carbon, the sensitivities were opposite. A potential transient net carbon sink greater than that predicted by the equilibrium response was estimated on time scales of decades–centuries, but diminished over longer time scales. Continued research should further explore the interactions between competition, dispersal, and disturbance, particularly in regards to vegetation redistribution.Item Parenting in place: Young children's living arrangement and migrants' sleep health in South Africa(Wiley, 2023-07-11) Madhavan, Sangeetha; Wan Kim, Seung; White, Michael; Gomez-Olive, XavierMigration research tends to treat childrearing as a secondary role for migrants. By prioritising the economic objectives of migration, most models present migrants as either delaying childbearing or, if they have young children, not living with them. However, migration has become increasingly feminised, the types of mobility more varied, while the returns to migration remain uncertain at best. At the same time, norms around childrearing are shifting, and the capacity of kin to take care of children may be weakening. In such contexts, migrants may not want to or be able to be separated from their children. Confronting such difficult decisions and their consequences may be reflected in poor sleep health for the migrant parent. We draw on data from the Migration and Health Follow-Up Study (MHFUS) in South Africa to examine the following questions: (i) To what extent is children's coresidence associated with sleep health for migrant parents? (ii) Do effects vary by sex of migrant? and (iii) Do effects vary by location of migrant? Results from propensity score matching confirm that migrants who coreside with all their young children are more likely to experience healthy sleep compared to those who have nonresident or no young children. However, stratified analysis shows that these effects are only significant for women and those not living in Gauteng province. The value of these findings is underscored by the need for research on the well-being of migrant parents who are negotiating multiple agendas in economically precarious and physically insecure destinations.Item Essays in Gender and Development(2023) SIVARAM, ANUSUYA; Goldberg, Jessica; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation consists of three essays at the intersection of gender and economics in developing countries. In chapter 1, I study the economic implications of a particular cultural practice: cousin, or consanguineous, marriage. One sixth of all marriages in Egypt are between first cousins, but there are important differences in the characteristics of individuals who select into such relationships relative to those who marry non-relatives. To measure the causal impact of the practice on socioeconomic outcomes abstracting from selection, I instrument for the probability of marrying a cousin using exogenous variation in family structure, and use weak instrument robust methods to estimate parameters and evaluate statistical significance. I find that individuals who marry a cousin because of exogenous attributes of their natal family structure are further in age from their spouse, predominantly driven by older men marrying cousins. I also find that women married to cousins receive higher levels of marital transfers that give them bargaining power within their marriages, likely as compensation for their spouse's attributes. This contrasts to patterns for those who select into cousin marriage; those individuals are younger at the time of marriage, match with partners closer to their own ages, and have no differences in the level of marital transfers exchanged. The contrast between OLS and IV results suggests that selection into cousin marriage may be motivated by anticipation of not matching on the wider marriage market, credit constraints, or the desire to consolidate property within the extended family. In chapter 2, I present baseline statistics from an experiment which examines the impact of random job offers on women's experiences of intimate partner violence in Bangladesh. This paper build on a larger study which aims to increase women's labor force participation and use of mobile money services. I collect supplementary data on women's experiences of intimate partner violence, men and women's agreement with conservative social norms, and second order beliefs regarding their community's sanction of intimate partner violence. I validate survey measures of intimate partner violence with a list randomization elicitation. I also present results from two incentivized decisionmaking activities conducted at baseline. I specify the outcomes I plan to test once endline data is available, as well as the econometric specifications I will use. Finally, I present power calculations using baseline data to determine the smallest effect sizes I can detect. Finally, in chapter 3, I study the impact of an exogenous negative shock to labor demand for female migrants within Bangladesh. I use a difference in differences strategy and compare outcomes between districts that have a history of sending migrants with those that do not, before and after the shock. I find that migrants respond to the initial shock and return to their households rather than remain unemployed in Dhaka, and that at least some of these women marry. I see no decrease in the level of investment in children's human capital, which suggests households do not revise their perceptions regarding the returns to education, and have access to other tools to smooth consumption. Finally, I see no changes in the daily agricultural wage rate for women in the years after the shock. I lack data on several important margins of adjustment which would allow us to discern the mechanisms behind the effects.Item The Ecological Velocity of Climate Change(2020) O'Leary, Donal Sean; Hurtt, George C; Geography; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Vegetation productivity and distributions are largely driven by climate, and increasing variability in seasonal and interannual climate is both changing the spatiotemporal patterns of resource availability across the landscape, and driving species’ migrations towards climate refugia. Climate and vegetation dynamics take place along the time dimension (e.g. earlier snowmelt and arrival of spring in temperate mountains), but they also occur throughout space, where changes in climate can be expressed as a movement across the landscape (e.g. warm temperatures and migratory animals moving uphill in spring, or tree species distributions moving uphill and towards the poles under climate change). Here, we present new methods to track the movement of climate and vegetation, quantifying the ecological velocity of climate change at the landscape scale. Our focus is on national parks of the USA, which are important study areas because of their great conservation and social value, protection from anthropogenic disturbances, and longstanding research and monitoring records. First, we explore the spatio-temporal relationships between snowmelt timing and vegetation phenology in Crater Lake National Park. We find that snowmelt timing is closely linked to spring greenup, but has far weaker influence on later season phenology, such as the senescence or growing season length. Second, we extend our comparison of snowmelt timing with vegetation phenology across space and time together as we track the speed and direction of receding seasonal snowpack (snowmelt velocity) with the ‘green wave velocity’ of spring greenness that follows. We find that snowmelt velocity has a moderate predictive power for green wave velocity in areas with steep slopes, where both phenomena are controlled by strong spatial gradients relating to elevation. Third, we extend our analysis into the future as we forecast the climate velocity of air temperature and precipitation in and surrounding national parks from 2019-2099. Here, we identify possible corridors and velocities of future climate migration across park boundaries, highlighting locations of ecological concern and climate vulnerability. Taken together, our analysis of the ecological velocity of climate change forms new connections among climate, conservation, and spatial sciences while prioritizing management-relevant deliverables.Item Essays on Individual Responses to Labor Market Conditions and Policies(2018) Wilson, Riley; Kearney, Melissa S; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation examines how individuals respond to changing conditions and policies in the labor market, with a particular interest in understanding economically motivated migration and labor force attachment. I first turn to the question of labor mobility. There is long-standing academic and policy interest in the issue of economically motivated geographic mobility. I examine the recent context of localized "fracking" booms in the United States to explore the migration response to positive labor demand shocks. Using data from 1999 to 2013, I show that local fracking led to large increases in potential earnings and employment rates, as well as a sizable migration response. But, this average migration effect masks substantial underlying heterogeneity in migration behavior across both demographics and regions. Migrants to fracking areas were more likely to be male, unmarried, young, and less educated than movers more generally. Furthermore, both in- and out-migration rates increased with fracking and both flows were driven by the same demographic groups, suggesting fracking resulted in short-term migration and increased churn. An instrumental variables analysis using fracking conditions to instrument for earnings suggests that a ten percent increase in average earnings increased in-migration rates by 3.8 percent in North Dakota fracking counties, as compared to only 2.4 percent in the West, 1.6 percent in the South, and 0.5 percent in the Northeast. The difference across regions is statistically significant; robust to housing market controls, geographic spillovers, and other various specifications; and is only partially explained by differences in commuting behavior, initial population characteristics, or a non-linear relationship between earnings and migration. There is some evidence that heterogeneous information flows might be driving the heterogeneous migration response. This implies that lack of information might be dampening rates of migration to economically favorable labor markets. I next examine how labor market information affects these types of economically motivated migration decisions. Migration is a human capital investment that allows individuals to encounter more favorable labor markets. I exploit county-level variation in exposure to news about labor markets impacted by fracking, to show that access to information about potential labor market opportunities affects migration. I use pre-fracking newspaper circulation rates and content from national news outlets to capture exogenous variation in exposure to news about fracking in a particular destination. I then isolate the effect of news exposure by comparing migration flows to the same destination from differentially exposed origin counties. Exposure to newspaper articles about fracking increased migration to the areas mentioned in the news by 2.4 percent on average. News exposure also increases commuting to fracking counties. Exposure to TV news has a similar impact, and positive news about fracking increases migration more than negative news. As further evidence that news matters, Google searches for the term fracking and the names of states specifically mentioned spike after TV news broadcasts about fracking. Migration responses to news about fracking are largest from counties experiencing weak labor markets, suggesting these areas see the largest benefits to information provision. Finally, I examine how a well known government policy aimed to incentize labor force participation -- the Earned Income Tax Credit (EITC)-- affects labor force transitions. Less-educated single women frequently transition in and out of the labor force. Although there is evidence that the Earned Income Tax Credit (EITC) increases annual labor force participation, it is unclear how it affects these high frequency, within year employment decisions and entry and exit. By exploiting the panel nature of the Current Population Survey, I overcome challenges associated with compositional changes and estimate the impact of increases in EITC generosity on employment transitions. EITC expansions induce less-educated single women who were previously attached to the labor force to work more months, leading stronger labor force attachment and more annual weeks worked. This leads to less annual exit, suggesting that the documented impact of the EITC on labor force participation rates in part operates by keeping previously employed single women in the labor force. This highlights the importance of understanding how income support programs affect not only labor force participation, but transitions as well. Employment decisions respond to increases in the maximum EITC credit eligible to receive in the current year, rather than the maximum credit eligible to earn, which differ because the EITC is a tax credit transferred with a one year lag. This would be consistent with workers basing their current work decisions on their lagged experience with the EITC. Further evidence additionally suggests that the employment response to the lagged EITC amount is likely due to information about the return to work, rather than to the relaxation of liquidity constraints.Item Violence and Belonging: The impact of citizenship law on violence in Sub-Saharan Africa(2016) Fruge, Anne Christine; Birnir, Johanna K; Government and Politics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Many countries in Africa are embroiled in heated debates over who belongs where. Sometimes insider/outsider debates lead to localized skirmishes, but other times they turn into minor conflict or even war. How do we explain this variation in violence intensity? Deviating from traditional explanations regarding democratization, political or economic inequality, or natural resources, I examine how nationality laws shape patterns in violence. Citizenship rules determine who is or is not a member of the national political community. Nationality laws formalize these rules, thus representing the legal bond between individuals and the state. Restrictive nationality laws increase marginalization, which fuels competition between citizenship regime winners and losers. This competition stokes contentious insider/outsider narratives that guide ethnic mobilization along the dual logics of threat and opportunity. Threats reduce resource levels and obstruct the exercise of rights. Opportunities provide the chance to reclaim lost resources or clarify nationality status. Other work explains conditions necessary for insider/outsider violence to break out or escalate from the local to the national level. I show that this violence intensifies as laws become more exclusive and escalates to war once an outsider group with contested foreign origins faces denationalization. Groups have contested foreign origins where the “outsider” label conflates internal and foreign migrants. Where outsiders are primarily in-migrants, it is harder to deny the group’s right to citizenship, so nationality laws do not come under threat and insider/outsider violence remains constrained to minor conflict. Using an original dataset of Africa’s nationality laws since 1989, I find that event frequency and fatality rates increase as laws become more restrictive. Through case studies, I explain when citizenship struggles should remain localized, or escalate to minor or major conflict. Next, I apply a nationality law lens to individual level conflict processes. With Afrobarometer survey data, I show that difficulty obtaining identity papers is positively correlated with the fear and use political violence. I also find that susceptibility to contentious narratives is positively associated with using violence to achieve political goals. Finally, I describe the lingering effects of a violent politics of belonging using original survey data from Côte d’Ivoire and Ghana.Item Plant Migrations Impact on Potential Vegetation and Carbon Redistribution in Northern North America from Climate Change(2016) Flanagan, Steven; Hurtt, George C; Geography; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Forests have a prominent role in carbon storage and sequestration. Anthropogenic forcing has the potential to accelerate climate change and alter the distribution of forests. How forests redistribute spatially and temporally in response to climate change can alter their carbon sequestration potential. The driving question for this research was: How does plant migration from climate change impact vegetation distribution and carbon sequestration potential over continental scales? Large-scale simulation of the equilibrium response of vegetation and carbon from future climate change has shown relatively modest net gains in sequestration potential, but studies of the transient response has been limited to the sub-continent or landscape scale. The transient response depends on fine scale processes such as competition, disturbance, landscape characteristics, dispersal, and other factors, which makes it computational prohibitive at large domain sizes. To address this, this research used an advanced mechanistic model (Ecosystem Demography Model, ED) that is individually based, but pseudo-spatial, that reduces computational intensity while maintaining the fine scale processes that drive the transient response. First, the model was validated against remote sensing data for current plant functional type distribution in northern North America with a current climatology, and then a future climatology was used to predict the potential equilibrium redistribution of vegetation and carbon from future climate change. Next, to enable transient calculations, a method was developed to simulate the spatially explicit process of dispersal in pseudo-spatial modeling frameworks. Finally, the new dispersal sub-model was implemented in the mechanistic ecosystem model, and a model experimental design was designed and completed to estimate the transient response of vegetation and carbon to climate change. The potential equilibrium forest response to future climate change was found to be large, with large gross changes in distribution of plant functional types and comparatively smaller changes in net carbon sequestration potential for the region. However, the transient response was found to be on the order of centuries, and to depend strongly on disturbance rates and dispersal distances. Future work should explore the impact of species-specific disturbance and dispersal rates, landscape fragmentation, and other processes that influence migration rates and have been simulated at the sub-continent scale, but now at continental scales, and explore a range of alternative future climate scenarios as they continue to be developed.Item Essays on Migration and Health(2013) Knaup, Amy E.; Betancourt, Roger; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Migration is often thought of as a risky endeavor in which a migrant trades a known low return for an unknown but potentially higher return. However, migration has been empirically linked to insurance mechanisms through remittances. Chapter 1 unifies the risk-taking and insurance-seeking behaviors of migration into a single framework by framing the migration decision as one of income diversification in which multiple agents within a household to decide whether or not to migrate. Each migration strategy (no migration, partial migration, and full household migration) has its associated risks which are weighed against the returns the household could gain through choice of that particular migration strategy. I test the framework by estimating the probability of each migration strategy for Indonesian households during the period 1993-1998. The framework performs reasonably well in the case of urban households. However, the framework's predictions do not hold as well for rural households, which may be linked to the fact that they function within a larger insurance network than the nuclear family. In Chapter 2, I find that the response of return migration to GDP per capita can differentiate migrants who are seeking increased consumption for their household (i.e., consumption-oriented migrants) from migrants with intentions to invest at origin (i.e., investment-oriented migrants). Each type of migrant should have differential responses to GDP per capita at destination and may have differential responses to GDP per capita at origin. Using data on Mexican households between 1992-2002, I show that migrants returning from the USA exhibit characteristics of consumption-oriented migrants and migrants returning from internal locations exhibit characteristics of investment-oriented migrants. Chapter 3 is a published work in collaboration with Sandra Decker, Jalpa Doshi, and Daniel Polsky which uses Medicare claims data linked to two different surveys--the National Health Interview Survey and the Health and Retirement Study--to describe the relationship between insurance status before age 65 years and the use of Medicare-covered services beginning at age 65 years. Although we do not find statistically significant differences in Medicare expenditures or in the number of hospitalizations by previous insurance status, we do find that individuals who were uninsured before age 65 years continue to use the healthcare system differently from those who were privately insured.Item The Changing Spatial Distribution of the Population of the Former Soviet Union(2009) Heleniak, Timothy Edmund; Geores, Martha E; Geography; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)When it existed, the Soviet Union was a closed economic and migration space with tightly-controlled movement of goods, people, and ideas across its borders. It was also an ethnically complex region with 130 different nationalities, fifty-three with territorially-based ethnic homelands, of which fifteen became the successor states to the Soviet Union. The breakup of the Soviet Union, the transition towards market economies, and the liberalization of the societies have together greatly impacted the lives of people in the region. Many found themselves in countries or regions with dramatically shrunken economies or as ethnic minorities in newly independent states and many have chosen migration as a strategy of adaptation to the new circumstances in which they found themselves. Using established migration theory, this dissertation examines the causes of migration among the fifteen successor states since 1991. The main test was to compare the relative impact of economic factors versus ethnic factors driving migration movements in the post-Soviet space. The results showed that while some of the movements could be classified as people migrating to their ethnic homelands, a majority could be explained by neoclassical economic theories of migration and the large income differentials that have resulted from the economic transition. Other theories that have been found to explain migration in other world migration systems were found to also be applicable in the former Soviet Union.Item Civil Liberties, Mobility, and Economic Development(2009) BenYishay, Ariel; Betancourt, Roger R.; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)To what extent do civil liberties affect economic development? This dissertation addresses this question in two essays. The first chapter (joint with Roger Betancourt) provides a new economic interpretation of civil liberties as rights over a person's most basic human asset: her own self. The importance of these rights to economic development is based on the principle that property rights-defined over a broad set of "property''-are crucial for economic growth. The empirical literature to date shows little support for such claims related to civil liberties, however, with ambiguous evidence on the role of these rights in driving long-run growth. Using newly available data from Freedom House, we find that one of the recently disaggregated categories of civil liberties explains income differences across countries more powerfully and robustly than any other measure of property rights or the rule of law considered. This component, entitled "Personal Autonomy and Individual Rights,'' evaluates the extent of personal choice over issues such as where to work, study, and live, as well as a broader set of property rights and other choices. While the first chapter finds that greater civil liberties can substantially improve long-run economic development, the second chapter identifies a key friction in this relationship. In countries that lack complementary institutions, civil liberties governing individual mobility can complicate credit transactions. By allowing individuals to move to locations where less is known about their prior defaults, mobility freedoms induce opaqueness and can result in credit rationing. I develop an instrumental variable estimation to study these effects, which would otherwise be complicated by omitted variable bias and endogeneity. Using household survey data from Guatemala, I instrument for individual migration with the interaction of violence patterns and individual sensitivities toward that violence. Using this approach, I find that the act of migration within a country actually causes individuals to have significantly less access to credit, primarily because lenders are concerned about these borrowers' opportunistic default.