Clicking on Heaven’s Door: The Effect of Immigrant Legalization on Crime
利用意大利每年固定配额、先到先得的居留许可申请制度，通过回归断点设计发现，移民合法化使合法化移民的犯罪率平均降低0.6个百分点（基线犯罪率为1.1%）。
We estimate the effect of immigrant legalization on the crime rate of immigrants in Italy by exploiting an ideal regression discontinuity design: fixed quotas of residence permits are available each year, applications must be submitted electronically on specific “click days,” and are processed on a first come, first served basis until the available quotas are exhausted. Matching data on applications with individual-level criminal records, we show that legalization reduces the crime rate of legalized immigrants by 0.6 percentage points on average, on a baseline crime rate of 1.1 percent.