Police brutality, law enforcement, and crime: Evidence from Chicago

It is a popular belief that police brutality incidents increase crime either by causing retaliation (i.e. rioting) or depolicing. But, these incidents may also deter crime, which makes the sign of the effect of brutality and crime ambiguous. In this paper, I build a simple model that highlights this theoretical ambiguity and provides guidance on how to use the joint effects of brutality on crime and arrests to distinguish between these three mechanisms: retaliation, depolicing, and deterrence. Using data on excessive force complaints in Chicago from 2011 to 2015, I exploit variation in the timing and location of serious excessive force incidents to estimate the effect of police brutality on crime rates and arrests rates within Chicago. I find that communities that experience serious brutality incidents experience a 2.1% increase in total crime in the month following the incident. These local crime rate increases are roughly five times larger when the victim is black and the officer is white (i.e. when incidents are racially charged). Racially charged incidents also result in large short-term increases in arrest rates (especially for violent crimes). These results are inconsistent with deterrence at the local level and highlight that the joint criminogenic and enforcement response to police brutality varies substantially by the racial composition of those involved. In addition, I also document some evidence of small post-incident city-wide declines in crime and arrests, highlighting the possibility that different mechanisms may matter at different scales of analysis. Contrary to public perception, I do not any find clear evidence of depolicing.