Previous empirical studies have typically uncovered little evidence that police reduce crime.
One problem with those studies is a failure to adequately deal with the simultaneity between
police and crime: while police may or may not reduce crime, there is little doubt that
expenditures on police forces are an increasing function of the crime rate. In this study, the
timing of mayoral and gubernatorial elections is used to identify the effect of police on crime.
This paper first demonstrates that increases in the size of police forces disproportionately …

Justin McCrary (2002) demonstrates that a paper of mine on the subject of elections, police,
and crime published in this journal (Levitt, 1997) suffers from programming and classification
errors. It is with tremendous personal embarrassment that I acknowledge these mistakes,
and I thank McCrary for his careful work that has laid bare these errors. While any mistake in
published work is unacceptable, I take some small solace in the fact that the particular errors
I made have a relatively small impact on the results. For individual crime categories, the …