Immigration Enforcement and Crime
研究了移民执法对无证移民犯罪率的影响，利用意大利对不同国籍移民执法力度的差异，发现更严格的执法降低了无证移民的犯罪率。
Immigration enforcement has ambiguous implications for the crime rate of undocumented immigrants. On the one hand, expulsions reduce the pool of immigrants at risk of committing crimes, on the other they lower the opportunity cost of crime for those who are not expelled. We estimate the effect of expulsions on the crime rate of undocumented immigrants in Italy exploiting variation in enforcement toward immigrants of different nationality, due to the existence of bilateral agreements for the control of illegal migration. We find that stricter enforcement of migration policy reduces the crime rate of undocumented immigrants.