Migrants to the United States are a diverse population. This diversity, captured in various migration theories, is overlooked in empirical applications that describe a typical narrative for an average migrant. Using the Mexican Migration Project data from about 17,000 first-time migrants between 1970 and 2000, this study employs cluster analysis to identify four types of migrants with distinct configurations of characteristics. Each migrant type corresponds to a specific theoretical account, and becomes prevalent in a specific period, depending on the economic, social and political conditions. Strikingly, each migrant type also becomes prevalent around the period in which its corresponding theory is developed.

This paper studies the impact of internal migration and remittance flows on wealth accumulation and distribution in 51 rural villages in Nang Rong, Thailand. Using data from 5,449 households, the study constructs indices of household productive and consumer assets with principal component analysis. The changes in these indices from 1994 to 2000 are modeled as a function of households’ prior migration and remittance behavior with ordinary least squares, matching, and instrumental variable methods.  The findings show that rich households lose productive assets with migration, potentially due to a reduction in the labor force available to maintain local economic activities, while poor households gain productive assets due to a reduction in the consumption burden and an influx of remittances. Regardless of wealth status, households do not gain or lose consumer assets with migration or remittances. These results suggest an equalizing effect of migration and remittances on wealth distribution in rural Thailand.

Background: Human cadavers are crucial to numerous aspects of health care, including initial and continuing training of medical doctors and advancement of medical research. Concerns have periodically been raised about the limited number of whole body donations. Little is known, however, about a unique form of donation, namely co-donations or instances when married individuals decide to register at the same time as their spouse as whole body donors. Our study aims to determine the extent of whole body co-donation and individual factors that might influence co-donation. Methods and Findings: We reviewed all records of registrants to the University of Hawaii Medical School’s whole body donation program from 1967 through 2006 to identify married registrants. We then examined the 806 married individuals’ characteristics to understand their decision to register alone or with their spouse. We found that married individuals who registered at the same time as their spouse accounted for 38.2 percent of married registrants. Sex differences provided an initial lens to understand co-donation. Wives were more likely to co-donate than to register alone (p = 0.002). Moreover, registrants’ main occupational background had a significant effect on co-donations (p = 0.001). Married registrants (regardless of sex) in female-gendered occupations were more likely to co-donate than to donate alone (p = 0.014). Female-gendered occupations were defined as ones in which women represented more than 55 percent of the workforce (e.g., preschool teachers). Thus, variations in donors’ occupational backgrounds explained co-donation above and beyond sex differences. Conclusions: Efforts to secure whole body donations have historically focused on individual donations regardless of donors’ marital status. More attention needs to be paid, however, to co-donations since they represent a non-trivial number of total donations. Also, targeted outreach efforts to male and female members of female-gendered occupations might prove a successful way to increase donations through co-donations.

Prior work has modeled individuals’ migration and remittance behavior separately, and reported mixed empirical support for various remittance motivations. This study offers an integrated approach, and considers migration as a mechanism for selection in a censored probit model of remittance behavior. This approach leads to different conclusions about the determinants of remittance behavior in the Thai internal migration setting. To the extent that these determinants capture different remittance motivations, as prior research has presumed, the analysis also provides varying support for these motivations. These results suggest that migration and remittance behavior are interrelated, and it is crucial for an analysis of remittance behavior to control for the selectivity of migration.

Students of social inequality have noted the presence of mechanisms militating toward cumulative advantage and increasing inequality. Social scientists have established that in-­‐ dividuals’ choices are influenced by those of their network peers in many social domains. We suggest that the ubiquity of network effects and tendencies towards cumulative advant-­‐ age are related. Inequality is exacerbated when effects of individual differences are multi-­‐ plied by social networks: when persons must decide whether to adopt beneficial practices; network externalities, social learning, or normative pressure influence adoption decisions; and networks are homophilous with respect to individual characteristics that predict such decisions. We review evidence from literatures on network effects on technology, labor markets, education, demography, and health; identify several mechanisms through which networks may generate higher levels of inequality than one would expect based on dif-­‐ ferences in initial endowments alone; consider cases where network effects may amelior-­‐ ate inequality; and describe research priorities.

To evaluate the distributional impact of remittances in origin communities, prior research studied how migrants’ selectivity by wealth varies with migration prevalence in the community or prior migration experience of the individual. This study considers both patterns, and examines selectivity separately in low and high prevalence communities and for first-time and repeat migrants. Based on data from 18,042 household heads in 119 Mexican communities from the Mexican Migration Project, the analyses show that (i) first-time migrants in low prevalence communities come from poor households, while repeat migrants in high prevalence communities belong to wealthy households, and (ii) higher amounts of remittances reach wealthy households. These results suggest that repeat migration and remittances may be mechanisms for wealth accumulation in the study communities. Descriptive analyses associate these mechanisms with increasing wealth disparities between households with and without migrants, especially in high prevalence communities. The study, similar to prior findings, shows the importance of repeat migration trips, which, given sustained remittances, may amplify the wealth gap between migrants and non-migrants in migrant-sending communities. The study also qualifies prior findings by differentiating between low and high prevalence communities and observing a growing wealth gap only in the latter.

We describe a common but largely unrecognized mechanism that produces and exacerbates intergroup inequality: the diffusion of valuable practices with positive network externalities through social networks whose members differentially possess characteristics associated with adoption. We examine two cases, the first to explicate the implications of the model, the second to demonstrate its utility in analyzing empirical data. In the first, the diffusion of Internet use, network effects increase the utility of adoption to friends and relatives of prior adopters. An agent-based model demonstrates positive, monotonic relationships, given externalities, between homophily bias and intergroup inequality in equilibrium adoption rates. In the second, rural/urban migration in Thailand, network effects reduce risk to persons whose networks include prior migrants. Using longitudinal individual-level migration data, we find that network homophily interacts with network externalities to induce inequality in migration rates among otherwise similar villages.

Sociological research often examines the effects of social context with hierarchical models. In these applications, individuals are nested in social contexts—like school classes, neighborhoods or villages—whose effects are thought to shape individual outcomes. Although applications of hierarchical models are common in sociology, analysis usually focuses on inference for fixed parameters. Researchers seldom study model fit or examine aggregate patterns of variation implied by model parameters. We present an analysis of Thai migration data, in which survey respondents are nested within villages and report annual migration information. We study a variety of hierarchical models, investigating model fit with DIC and posterior predictive statistics. We also describe a simulation to study how different initial distributions of migration across villages produce increasing inter-village inequality in migration.

This paper studies how increasing migration changes the character of migrant streams in sending communities. Cumulative causation theory posits that past migration patterns determine future flows, as prior migrants provide resources, influence, or normative pressures that make individuals more likely to migrate. The theory implies exponentially increasing migration flows that are decreasingly selective. Recent research identifies heterogeneity in the cumulative patterns and selectivity of migration in communities. We propose that this heterogeneity may be explained by individuals’ differential access to previously accumulated migration experience. Multi-level, longitudinal data from 22 rural Thai communities allow us to measure the distribution of past experience as a proxy for its accessibility to community members. We find that migration becomes a less-selective process as migration experience accumulates, and migrants become increasingly diverse in socio-demographic characteristics. Yet, selectivity within migrant streams persists if migration experience is not uniformly distributed among, and hence not equally accessible to, all community members. The results confirm that the accumulation and distribution of prior migrants’ experiences distinctly shape future migration flows, and may lead to diverging cumulative patterns in communities over time.

This paper investigates how migrant social capital differentially influences individuals’ migration and cumulatively generates divergent outcomes for communities. To combine the fragmented findings in the literature, the paper proposes a framework that decomposes migrant social capital into resources (information about or assistance with migration), sources (prior migrants), and recipients (potential migrants). Analysis of multi-level and longitudinal data from 22 rural villages in Thailand shows that the probability of internal migration increases with the available resources, yet the magnitude of increase depends on recipients’ characteristics and the strength of their ties to sources. Specifically, individuals become more likely to migrate if migrant social capital resources are greater and more accessible. The diversity of resources by occupation increases the likelihood of migration, while diversity by destination inhibits it. Resources from weakly-tied sources, such as village members, have a higher effect on migration than resources from strongly-tied sources in the household. Finally, the importance of resources for migration declines with recipients’ own migration experience. These findings challenge the mainstream account of migrant social capital as a uniform resource that generates similar migration outcomes for different groups of individuals or in different settings. In Nang Rong villages, depending on the configuration of resources, sources and recipients, migrant social capital leads to differential migration outcomes for individuals and divergent cumulative migration patterns in communities.

A review of the sociological research about gender and migration shows the substantial ways in which gender fundamentally organizes the social rela- tions and structures influencing the causes and consequences of migration. Yet, although a significant sociological research has emerged on gender and migration in the last three decades, studies are not evenly distributed across the discipline. In this article, we map the recent intellectual history of gender and migration in the field of sociology and then systematically assess the extent to which studies on engendering migration have appeared in four widely read journals of sociology (American Journal of Sociology, American Sociological Review, Demography, and Social Forces). We follow with a discussion of these studies, and in our conclusions, we consider how future gender and migration scholarship in sociology might evolve more equitably.

Employing longitudinal data from Thailand to replicate studies of cumulative causation, we extend current knowledge by measuring frequency of trips, duration of time away, level of network aggregation (village or household), and sex composition of migrant networks to estimate a model of prospective migration among men and women in Thailand. We find that trips and duration of time away have distinct influences upon migration; that household level migrant networks are more influential than village level migrant networks; that female migrant networks and male migrant networks have different influences upon migration outcomes; and, that migrant social capital influences men and women's migration differently. Our elaboration provides significant quantitative evidence as to how gender and family variously imbue migration dynamics.