Source: Thomas J. Miles, Adam B. Cox, University of Chicago Coase-Sandor Institute for Law & Economics Research Paper No. 705, August 21, 2014
From the abstract:
Does immigration enforcement actually reduce crime? Surprisingly, little evidence exists either way — despite the fact that deporting noncitizens who commit crimes has been a central feature of American immigration law since the early twentieth century. We capitalize on a natural policy experiment to address the question and, in the process, provide the first empirical analysis of the most important deportation initiative to be rolled out in decades. The policy initiative we study is “Secure Communities,” a program designed to enable the federal government to check the immigration status of every person arrested for a crime by local police. Before this program, the government checked the immigration status of only a small fraction of arrestees. Since its launch, the program has led to over a quarter of a million detentions. We exploit the slow rollout of the program across more than 3,000 U.S. counties to obtain differences-in-differences estimates of the impact of Secure Communities on local crime rates. We also use rich data on the number of immigrants detained under the program in each county and month — data obtained from the federal government through extensive FOIA requests — to estimate the elasticity of crime with respect to incapacitated immigrants. Our results show that Secure Communities led to no meaningful reductions in the FBI index crime rate. Nor has it reduced rates of violent crime — homicide, rape, robbery, or aggravated assault. This evidence shows that the program has not served its central objective of making communities safer.