The Deterrent Effect of Targeted and Salient Police Enforcement: Evidence from Bans on Checkpoints for Driving under the Influence

I estimate the causal effect of checkpoints for driving under the influence of drugs and/or alcohol (DUI) on traffic fatalities, DUI arrests, and self-reported incidents of DUI. Exploiting quasi-random variation in state-level laws that ban checkpoints for DUI, I find a 12.4 percent increase in DUI-related traffic fatalities within the first 5 years following a DUI checkpoint ban. I also find a persistent increase in DUI arrests and a short-run increase in self-reported DUI behavior. Together, these findings suggest that targeted, salient police enforcement has a general deterrent effect on dangerous driving. Furthermore, back-of-the-envelope calculations suggest that a federal ban on DUI checkpoints would lead to an annual cost of approximately $6.4 billion in terms of lives lost from DUI incidents.