Punishment and Deterrence: Evidence from Drunk Driving

Traditional economic models of criminal behavior have straightforward predictions: raising the expected cost of crime via apprehension probabilities or punishments decreases crime. I test the effect of harsher punishments on deterring driving under the influence (DUI). In this setting, punishments are determined by strict rules on Blood Alcohol Content (BAC) and previous offenses. Regression discontinuity derived estimates suggest that having a BAC above the DUI threshold reduces recidivism by up to 2 percentage points (17 percent). Likewise having a BAC over the aggravated DUI threshold reduces recidivism by an additional percentage point (9 percent). The results suggest that recent recommendations to lower the BAC limit to .05 would save relatively few lives, while increasing marginal punishments and sanctions monotonically along the BAC distribution would more effectively deter the drunk drivers most likely to be involved in fatal crashes.