Border Walls

What are the economic impacts of a border wall between the United States and Mexico? We use detailed data on bilateral ows of primarily unauthorized Mexican workers to the United States to estimate how a substantial expansion of the border wall between the United States and Mexico from 2007 to 2010 affected migration. We use these effects to estimate a general equilibrium spatial model featuring multiple labor types and quantify the economic impact of the wall expansion. At a construction cost of approximately $7 per person in the United States, we estimate that the border wall expansion harmed Mexican workers and high-skill U.S. workers, but benefited U.S. low-skill workers, who on average achieved welfare gains equivalent to an increase in per capita income of $0.28 per year.