Political economy, sectoral shocks, and border enforcement

In this paper, we examine the correlation between sectoral shocks and borde r enforcement in the United States, the U.S. government's main policy instr ument for combating illegal immigration. We see whether border enforcement falls following positive shocks to sectors that are intensive in the use of undocumented labour, as would be consistent with political economy models of illegal immigration. We find that border enforcement is negatively corre lated with lagged relative price changes in the apparel, fruits and vegetab les, and livestock industries and with housing starts in western United Sta tes, suggesting that authorities relax border enforcement when demand for u ndocumented labour is high.