When it comes to studying unauthorized migration, there is no perfect data set. The fact that undocumented migrants are clandestine means they necessarily fall outside the reach of the usual statistical systems, and the irregularity and marginality of their position in society makes it difficult to gather information on them using alternative methods. The best one can hope for is a triangulation that gets at the truth from multiple angles using diverse data sources that have complementary strengths and weaknesses. Despite obvious challenges, however, demographers have made considerable progress in assessing the numbers, characteristics, and behavior of undocumented migrants in the United States, especially those from Mexico.
Although they are clearly underenumerated, undocumented migrants are nonetheless captured to a significant extent in U.S. demographic surveys, such as the Current Population Survey (CPS) and the American Community Survey (ACS), and to an even greater extent in Mexican surveys, such as the National Survey of Population Dynamics (known as ENADID), the National Survey of Occupation and Employment (ENOE), and the Mexican Family Life Survey (MxFLS). Demographers have gotten quite good at using these data sources to derive reliable indirect estimates about the size and demographic composition of the undocumented population of the United States. In addition, data on the characteristics and behavior of undocumented migrants have been compiled using targeted surveys, such as those of the Mexican Migration Project (MMP), the Survey of Migration at the Border (EMIF), and other smaller studies. Although they cannot provide information on the total number of migrants or representative portraits of their characteristics, these surveys yield important insights into the motivations, actions, and processes underlying the larger patterns.
At this juncture, all the leading data sources point to a remarkable conclusion: after six decades of continuous in-movement, Mexican immigration has achieved a hiatus. Undocumented migration has fallen to a net rate of zero, and permanent legal immigration has slowed. At the same time, cross-border circulation in temporary legal categories has increased, and the size of the undocumented population has stabilized at roughly 11 million persons. At this point, few undocumented migrants are arriving (mostly for purposes of family reunification), but few are also going home, and despite record numbers of deportations, the size of the unauthorized population is not decreasing.
The current study by Amuedo-Dorantes et al., which is based on a new survey at the border, provides insight into the situation of undocumented migrants in the United States during the current era of high anti-immigrant sentiment and draconian enforcement. Like all data sets on undocumented migrants, this one has its flaws. It is a probability sample of migrants returning from the United States, both voluntarily and involuntarily, through the Tijuana sector. As such, it is not representative of all undocumented migrants living in the United States or even those headed home, given that Tijuana receives just 37 % of the return flow. It does, however, offer a view of undocumented life for two key subsets of the population: former undocumented residents seeking to return to Mexico, clearly a minority today; and those who were intending to stay but were unlucky enough to get caught, who may or may not reflect the experiences of those left behind. Whether the return was forced or voluntary, however, the socioeconomic traits of the two groups are quite similar, with a few exceptions: volunteers are more likely to be married and to have lived with a partner in the United States but are less likely to have U.S. children, whereas deported migrants, perhaps unsurprisingly, have more prior arrests and deportations.
Reports from these respondents suggest that undocumented life in the United States is quite tough: a third reported difficulty obtaining government assistance, a fifth said they had problems accessing legal services and health care, and half reported a fear of deportation. Despite these issues, however, a large majority intended to come back to the United States in the near future—three-quarters of those who had returned voluntarily and two-thirds of those who were just deported. Whatever the effect of enforcement on access to public services, it does not seem to have a very large deterrent effect on migrants.
A major shift in U.S. policy over the past decade has been the cooptation of states into immigration enforcement by federal authorities through efforts such as the 287(g) program and the E-Verify mandate. In states that enacted the latter, employers are required to verify the legal status of new hires. When the authors tested for the effects of E-Verify across states, however, they found that the program had no effect on access to services but had a huge positive effect on the fear of deportation and a huge negative effect on the rate of interstate mobility. The migrants were thus fearful and immobile. E-Verify also had no main effect on plans to return northward, and the effect of deportation itself was positive, although this positive effect was partially offset if the deportation was from an E-Verify state. The main effect of U.S. enforcement policy today is thus to marginalize and terrify undocumented migrants while not affecting their access to public services or influencing their migratory intentions. How long this situation persists depends very much on future policy action. Given the strong support that Latinos provided to President Obama and Senate Democrats in the 2012 elections, it seems clear that they will move forward on comprehensive immigration reform. The key question is whether the results of the election and the obviously rising political power of Hispanics will be enough to convince House Republicans to drop their obdurate opposition to any mention of immigration reform and move forward to solve the serious problems before us.