News Release

Arizona work law found to affect US-Mexico migration

Peer-Reviewed Publication

Carnegie Mellon University

The current political environment has led to an increased focus on the issue of unauthorized migration from Mexico and Central America, with proposals ranging from reforming the U.S. immigration system to building a wall along the U.S.-Mexican border. A new study used data from a Mexican identification-card program to find that a relatively low-cost employment-focused system can reduce unauthorized migration.

The study, by researchers at Carnegie Mellon University and the University of Colorado-Boulder, appears in the journal Demography.

"For the first time, our study shows that state-level immigration restrictions in the United States were effective in deterring the flow of unauthorized migrants into this country," explains Brian K. Kovak, assistant professor of economics and public policy at Carnegie Mellon University's Heinz College of Information Systems and Public Policy, who coauthored the study. "Previous research had shown that state-level employment restrictions reduced the size of a state's population of likely unauthorized individuals, but it wasn't clear whether enforcement diverted migrants to other U.S. destinations or if these policies slowed international migration."

The researchers measured geographic migration patterns using administrative data from a Mexican program that provides identification cards to Mexican citizens living abroad, along with additional migration data from the U.S. and Mexican census bureaus. Specifically, they examined where likely unauthorized Mexican immigrants lived in the United States and where they were born in Mexico. The data are unique because they cover the entirety of the United States and Mexico (including 75 U.S. destinations and more than 2,000 municipal areas in Mexico), and show where 7 million individuals came from and where they went.

Based on this information, the researchers showed that most communities in Mexico send migrants to a very specific set of destinations in the United States. As a result, migrants living in different U.S. states often came from very different parts of Mexico.

Using this information, the researchers then examined the effect of the Legal Arizona Workers Act (LAWA) on migration between Mexico and the United States. Under that law, passed in 2008, Arizona employers are required to use E-verify, a low-cost online system that verifies potential employees' identity and authorization to work in the United States. Recent federal comprehensive immigration reform proposals have included universal E-Verify as a central provision.

The researchers used Mexican census data to calculate changes in international migration rates from 2005 to 2010 for more than 2,000 Mexican municipalities. To determine the effect of LAWA, they then compared Mexican locations where migrants typically select Arizona as their destination to Mexican locations where migrants typically go elsewhere in the United States. In communities with stronger ties to Arizona, they found increased return migration from the United States and decreased emigration to the United States.

"Our findings show that labor-market interventions such as the E-verify program can affect international migration patterns, leading to a reduction in the total number of unauthorized migrants in the United States," notes Brian Cadena, associate professor of economics at the University of Colorado-Boulder, who coauthored the study. "This reduction would likely be even stronger when coupled with the legal guest worker provisions included in recent proposals for comprehensive immigration reform."


The research was funded by the Berkman Faculty Development Fund at Carnegie Mellon University.

Summarized from an article in Demography, Measuring Geographic Migration Patterns Using Matrículas Consulares, by Caballero, ME (Carnegie Mellon University), Cadena, BC (University of Colorado-Boulder and Institute of Labor Economics), Kovak, BK (Carnegie Mellon University, National Bureau of Economic Research, and Institute of Labor Economics). Copyright 2018. All rights reserved.

About Carnegie Mellon University's Heinz College

The Heinz College of Information Systems and Public Policy is home to two internationally recognized graduate-level institutions at Carnegie Mellon University: the School of Information Systems and Management and the School of Public Policy and Management. This unique colocation combined with its expertise in analytics set Heinz College apart in the areas of cybersecurity, health care, the future of work, smart cities, and arts & entertainment. In 2016, INFORMS named Heinz College the number one academic program for Analytics Education. For more information, please visit

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