Does expanding access to cannabis affect traffic crashes? County‐level evidence from recreational marijuana dispensary sales in Colorado

This article examines the effect of recreational cannabis dispensary sales on traffic crashes by employing difference‐in‐differences model that exploits the variation in the timing of recreational marijuana dispensary entry across counties within Colorado. Using marijuana‐related hospital discharge as a measure of marijuana abuse/misuse, the results indicate a sizable rise in marijuana‐related hospital discharges after the entry of retail cannabis stores. However, there is a lack of evidence that traffic crash incidents are affected by the entry. The preferred estimate suggests that, at 90% confidence level, a large increase in traffic crashes by more than 5% can be ruled out.