Person:

Garip, Filiz

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.

The authors 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. The authors examine two cases: the first, to explore the mechanism's implications and, the second, to demonstrate its utility in analyzing empirical data. In the first, the diffusion of Internet use, network effects increase adoption's benefits to associates 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. Analysis of longitudinal individual-level migration data indicates that network homophily interacts with network externalities to induce divergence of migration rates among otherwise similar villages.

The number of human cadavers available for medical research and training, as well as organ transplantation, is limited. Researchers disagree about how to increase the number of whole-body bequeathals, citing a shortage of donations from the one group perceived as most likely to donate from attitudinal survey data—educated white males over 65. This focus on survey data, however, suffers from two main limitations: First, it reveals little about individuals' actual registration or donation behavior. Second, past studies' reliance on average survey measures may have concealed variation within the donor population. To address these shortcomings, we employ cluster analysis on all whole-body donors' data from the Universities of California at Davis, Irvine, Los Angeles, and San Francisco. Two donor groups emerge from the analyses: One is made of slightly younger, educated, married individuals, an overwhelming portion of whom are U.S. born and have U.S.–born parents, while the second includes mostly older, separated women with some college education, a relatively higher share of whom are foreign born and have foreign-born parents. Our results demonstrate the presence of additional donor groups within and beyond the group of educated and elderly white males previously assumed to be most likely to donate. More broadly, our results suggest how the intersectional nature of donors' demographics, in particular, gender and migration status, shapes the configuration of the donor pool, signaling new ways to possibly increase donations.

This article 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 because of a reduction in the labor force available to maintain local economic activities, while poor households gain productive assets. 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.

Migrant networks—webs of social ties between migrants in destination and individuals in origin—are a key determinant of the magnitude and direction of migration flows, as well as migrants’ adaptation outcomes. The increasing emphasis on migrant networks represents a new approach to migration research, which until the late 1980s, had been dominated by economic or political explanations of migration.  This entry summarizes findings on migrant networks from relevant areas of research in anthropology, sociology, demography and economics; identifies the promising lines of inquiry recently undertaken; and points to key issues for future research, such as understanding how migrant networks impact migration behavior and migrants’ experiences. Such research into the specific mechanisms of social transmission will need to engage with the on-going discussions on networks effects and their identification in the social science literature at large, and will necessarily require the interdisciplinary collaboration of researchers.

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.

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.

Students of social inequality have noted the presence of mechanisms militating toward cumulative advantage and increasing inequality. Social scientists have established that individuals' choices are influenced by those of their network peers in many social domains. We suggest that the ubiquity of network effects and tendencies toward cumulative advantage are related. Inequality is exacerbated when effects of individual differences are multiplied by social networks: when persons must decide whether to adopt beneficial practices; when network externalities, social learning, or normative pressures influence adoption decisions; and when 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 differences in initial endowments alone; consider cases in which network effects may ameliorate inequality; and describe research priorities.

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.

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.