In recent years, criminologists, as well as journalists, have devoted considerable attention to the potential deterrent effect of what is sometimes referred to as "proactive" policing. This style of policing entails the vigorous enforcement of laws against relatively minor offenses in order to prevent more serious crime. The current study examines the effect of proactive policing on robbery rates for a sample of large U.S. cities using an innovative measure developed by Sampson and Cohen (1988). We replicate their cross-sectional analyses using data from 2000-2003, a period during which proactive policing is likely to have become more common than the period of the original study-the early 1980s. We also extend their analyses by estimating a more comprehensive regression model that incorporates additional theoretically-relevant predictors. Finally, we advance previous research in this area by using panel data. The crosssectional analyses replicate prior findings of a negative relationship between proactive policing and robbery rates. In addition, our dynamic models suggest that proactive policing is endogenous to changes in robbery rates. When this feedback between robbery and proactive policing is eliminated, we find further evidence that proactive policing reduces robbery rates.