Why do people

In research and public discourse, we often treat migrants as a homogeneous group. We assume they move from one country to another to do better. But motivations for migration can actually be quite diverse. My research shows this point in the Mexico-U.S. migration flow.

Motivations for migration change with the context.

We look at migrants, and see people of different races, religions, and ethnicities and yet, tell a single story about why they are here: to do better. We don’t realize that migrants are driven not just by personal goals, but also by circumstances beyond their control.

I studied the importance of the context in the Mexican migration that changed the face of America. Using fifty years of data from more than a hundred thousand people, and algorithms to uncover patterns, my research showed how migrants were swayed by forces much larger than them. And though we toss them into one group, and judge them together, I found, different events mobilized different kinds of people. Labor shortages in America pulled poor rural workers seeking opportunities. Crashing Mexican economy pushed middle-class young people looking to survive the crisis. And, increasing trade made it easier for educated workers from border cities to go back and forth. This analysis is summarized in a paper and elaborated in my book, On the Move: Changing Mechanisms of Mexico-U.S. Migration.

Migration map

Mexico map
Map of Mexico with 24 states categorized into three groups based on the share of urban migrants that state between 1965 and 2010. Map by Jeff Blossom, Center for Geographic Analysis, Harvard University. (Figure from On the Move 2016)

Migration becomes more of a social process over time.

It is easy to think of migration as an economic decision. But migration is also a social process. It is easier for people to migrate if they know others who have done so—they can learn about the journey or jobs in destination. It is also more acceptable for people to migrate if many people in their communities have migrated.

1 I studied this process in rural-to-urban migration in Thailand in the 1980s and 1990s, when the country led the world in economic growth. The new export-processing zones in urban centers attracted thousands of migrants there, changing the traditional livelihoods and family structures in rural communities forever. Using data from the Nang Rong project that surveyed about 20 thousand individuals in 51 communities in Thailand, I showed that some villages were closely tied to urban life by past migration. And it was these settings that fostered greater movement out of rural areas.

2 With Asad Asad, we explored a similar process in Mexico-U.S. migration using interview data. We observed network effects in migration—where an individual’s decision to migrate depends on the presence of other migrants in her network. We also found that the different mechanisms underlying these effects. In another paper with Asad, we used the Mexican Migration Project data to show that social factors come to matter more for migration decisions over time.

3 With Burak Eskici and Ben Snyder, we considered a social-influence process in migrant remittances in Thailand. We established that a migrant’s chances of remitting money to her family is associated with the presences of other remitters in her network.

Heat Map Figure

Heat Map of Migrant Attributes by Cluster Membership
Heat map of migrant attributes for four migrant groups identified with cluster analysis. A gray rectangle denotes the presence of an attribute, and a white one shows its absence. The black vertical lines separate the four clusters. (Figure from Garip 2012 PDR)

Migration can help left-behind families but also increase inequality.

Migrants send remittances to their families and communities. These funds—exceeding half a trillion annually according to the World Bank—reach the most deprived regions of the world. Remittances can alleviate poverty, but also increase inequality between families with migrants and those without.

I found evidence for both of these patterns in my research. In rural Thailand, I showed that remittance receipts are linked to productive asset gains for poor families. In Mexico, I observed that repeat migration and remittances are associated with increasing wealth inequality in migrant-sending communities.

Future migration is likely to be driven by climate change.

Migration as a result of environment and climate stressors has recently gained widespread interest, and dominates the political discourse in many countries. Climate change is projected to accelerate human displacement in the future by increasing the frequency and severity of extreme environmental events, such as droughts, sea level rise, floods, and hurricanes.

Our team (Nancy Chau, Allison Chatrchyan, Ariel Ortiz-Bobea and Amanda Rodewald) received a grant from the Cornell Atkinson Center for Sustainability to establish the linkages between gradual weather changes over the last fifty years and migration patterns from Mexico to the United States. We are now working on three papers from this project.