Monitoring Militarization: Erin Hamilton

By Michael Haggerty – At a time when the issue of immigration is more fiercely debated than ever, how does border militarization affect migrant families? In a recent paper, Associate Professor of Sociology Erin Hamilton seeks to find out.

In June 2015, launching his campaign for the presidency, Donald Trump proclaimed that Mexico was sending “people that have lots of problems, and they're bringing those problems with us. They're bringing drugs. They're bringing crime.” For the next year and a half, Trump emphasized the need for tighter border security. He openly courted the support of the United States Border Patrol and promised an “impenetrable, physical, tall, powerful, beautiful, southern border wall.” Though many voters disapproved of his generalizations about Mexicans, Trump’s support for border militarization was undoubtedly crucial to the success of his campaign.

It also forms part of a much larger story about the militarization of the U.S.-Mexico border. In recent years, sociologists, political scientists, and historians have been working to answer some of the many questions that militarization poses. For example, does border militarization successfully prevent the growth of an undocumented population in the United States? How does it affect economic and political relations between the U.S. and Mexico? And perhaps most importantly, what impact does it have on the lives of migrant laborers, many of whom come to the United States out of a basic desire for social and economic wellbeing?

Erin Hamilton’s 2016 article “Changes in the Transnational Family Structures of Mexican Farm Workers in the Era of Border Militarization” (co-authored with Jo Hale) explores the impact of border militarization on migrant families over the last thirty years. It provides insight into the deeply personal and often unintended consequences that border policing has had on the family structure of migrant people. We talked with Hamilton about the importance of her research at a time when issues related to immigration have taken center stage in American politics.

How did you become interested in sociology and what is it about the discipline that drove you to earn a PhD? 

I became interested in sociology after spending four months collecting survey data on migration and health in Mexico in 2002. I loved the experience of being in the field, learning about people’s lives. I was always interested in social issues—immigration, health care, international relations—but it was this experience that made me realize I also had a love for research. Sociology as a discipline appealed to me because of its breadth and flexibility. You can do so many different things in sociology.

How did your interest in Mexican farm workers and border militarization begin? Is this something you have been interested in for a long time or was it a recent turn in your research?

I’ve always been interested in Mexico-U.S. migration, and border militarization is a huge part of that story today. This particular project came about because I learned that the National Agricultural Workers Survey—the data we use in the research—includes both questions about the legal status of immigrant respondents, which is rare in survey data, and questions about the location of residence of dependent family members, which is also rare. Because the NAWS data has been collected on a sample of farm workers every year since 1989, and questions about the location of residence of children were first asked in 1993, my co-author Jo Hale and I realized it would be possible to analyze how border militarization, which began more or less in 1993, affected transnational family life in this population over time.

It turns out that farm workers also represent an ideal immigrant population through which to study this question. This is because agriculture relies heavily on undocumented workers and because the seasonal nature of farm work brought about circular migration between Mexico and the U.S., as well as the transnational family life that accompanies it.

Your article notes that the militarization of the U.S.-Mexico border disrupts transnational family life, interrupting a pattern of circular migration that began with the Bracero Program in the 1940s. How has transnational family life changed as a result of border militarization in the last twenty or thirty years?

Prior to the mid-1980s or so, the vast majority of Mexican migrants to the United States lived in “transnational families,” where members of the migrant’s nuclear family remained in Mexico. The common pattern was for men to migrate to the U.S. while women and children remained in Mexico. Some men did settle here, forming families, while others brought their families with them. Smaller numbers of women did the same. But most of the flow of migration between Mexico and the U.S. at that time was made up of individual migrants who left family-members behind, to whom they returned.

Several changes after the mid-1980s affected these patterns, one of them being the buildup of border control on the southwest border—what scholars have called “border militarization,” which makes it difficult to cross back and forth across the border. Since the early 1990s, we’ve seen changing routes of border crossings, rising costs of border crossings, and increased risk of death on the border as migrants attempt to evade apprehension.

But there’s little evidence that border control has deterred initial migration, at least through 2007. Rather, what we’ve seen is that the rising costs and risks of border crossings deter return migration to Mexico. Migrants have to work for longer in the U.S. to recoup the costs of migrating, and they skip trips home to avoid the risk of re-entry. This makes it difficult to live a transnational family life.

The rising costs and risks of border crossings deter return migration to Mexico.


Consistent with this idea, our research shows that over this period—from the late 1990s to 2012—there was a significant decline in the share of Mexican-born farm workers in the United States whose children and spouses live in Mexico. Among undocumented Mexican farm workers in the U.S., in 1997, about 70 percent had children who lived in Mexico. By 2012, it was only 20 percent.

We suspect this change was largely driven by farm workers starting families in the U.S., rather than migrating with family members from Mexico, but we don’t observe the location of birth of farm workers’ children in the data. Our research also suggests that this change was not simply a result of farm workers spending more time in the United States, although that was part of it—the change also occurred among recently arrived farm workers, suggesting that border control may have changed farm workers’ family migration strategies from the outset of their migrations.

Your article is consistent with a broader argument, put forth among scholars of Mexico-U.S. migration, that a rise in border policing actually creates a permanent population of undocumented migrants within the United States. Why do you think this argument is important for people to understand?

This argument is important because the stated intent of border control is to prevent undocumented migration to the United States—“prevention by deterrence.” In fact, the population of undocumented migrants and their U.S.-citizen family members in the United States grew dramatically over the same period that the U.S. government began and heavily invested in the policy of border control.

So, our research and the research of others suggests that the policy of border control has failed to reach its stated goal. But I share the view with many other researchers in this area that a more nefarious goal of border control policy is to appeal to nativist sentiment for political gain while at the same time continuing to procure a cheap and exploitable workforce for key industries, such as agriculture. This doesn’t seem to be Trump’s intent with the border wall, but I believe this interpretation applies to prior administrations. 

You argue that comprehensive immigration reform needs to include measures that provide permanent legal status to the undocumented population of the United States. Given the current political climate, how do you think scholars can go about promoting this argument? In other words, in an age when political rhetoric often stokes fear and anger, how do we produce policies that effectively deal with the political and social disenfranchisement of undocumented individuals?

Scholars should continue to research these issues with the same zeal and rigor as always but perhaps focus on informing policy at the state level, at least for the next few years. The CA Legislature has passed a number of laws that broaden the rights of undocumented people in CA—including increasing access to higher education, health care, and licenses. But more can be done. 

Currently, the CA Legislature is considering bills to prohibit the sharing of information between—and access by ICE to—public (state) institutions like schools, to provide funding for public defenders for immigrants in removal proceedings, and to train public defenders in the immigration consequences of criminal convictions. The work of scholars is essential to these efforts, insofar as that research helps legislators, policy experts, advocates, and voters understand the issues.

Learn more about Erin Hamilton.

Related: ISS Conference Confronts U.S. Immigration Policy.