Deterrent Effects of the Police on Crime: A Replication and Theoretical Extension

This study replicates and then extends Wilson and Boland's (1978) theory of the deterrent effect of policing on crime rates in American cities by linking it to recent thinking on control of urban disorder and incivilities (Sherman, 1986; Skogan and Maxfield, 1981). The theory posits that police departments with a legalistic style tend to generate policies of proactive patrol (e.g., high traffic citation rate and frequent stops of suspicious or disorderly persons), which in turn may decrease crime rates either (1) indirectly, by increasing the probability of arrest, or (2) directly, by decreasing the crime rate through a deterrent effect regarding perceived threat of social control. We test both these propositions in an examination of robbery rates in 171 American cities in 1980. Overall, the major results suggest that proactive policing has direct inverse effects on aggregate robbery rates, independent of known determinants of crime (e.g., poverty, inequality, region, and family disruption). Moreover, when we demographically disaggregate the robbery rate the direct inverse effect of aggressive policing on robbery is largest for adult offenders and black offenders. We examine the reasons for these findings and discuss their theoretical and policy implications.