The short-term and long-term deterrence effects of INS border and interior enforcement on undocumented immigration

This paper analyzes the short-term and long-term deterrence effects of INS border and interior enforcement. Utilizing FY1983-FY1997 border and interior apprehensions and patrol hours data from the INS, we estimate a four-variable VAR model and find that Border Patrol enforcement has significant short-term deterrence effects. These effects are short-lived as undocumented migrants seemingly adjust to new information. Moreover, the non-existent long-term effects are apparently the consequence of basic economic fundamentals: our analysis employing microdata from both Mexico and the US suggests that the wage gap between Mexico and the US is sufficiently large to maintain the illegal migratory flow.