Border Walls

Between 2006 and 2010 the U.S. government built an additional 548 miles of border wall along the U.S.-Mexico border. Combining survey data from all major border crossing points with administrative data on 5.7 million primarily unauthorized Mexican migrants, we study how the border wall expansion affected migration patterns and local labor markets. The wall changed migrants’ choice of route, their choice of destination within the United States, and their decision to migrate in the first place. On net, we estimate the wall decreased migration flows by three hundred thousand migrants, roughly one-third of the observed decline in Mexican migration between 2005 and 2015. Incorporating the decrease in migration into a spatial equilibrium model, we estimate that the wall increased (decreased) wages of low-skill (high-skill) U.S. workers by a modest $9 ($21) per year.