Do Traffic Tickets Reduce Motor Vehicle Accidents? Evidence from a Natural Experiment

This paper analyzes the effect of traffic tickets on motor vehicle accidents. Ordinary least squares (OLS) estimate may be upward biased because police officers tend to focus on areas where and periods when there is heavy traffic and thus higher rates of accidents. This paper exploits the dramatic increase in tickets during the Click‐it‐or‐Ticket campaign to identify the causal impact of tickets on accidents using data from Massachusetts. I find that tickets significantly reduce accidents and nonfatal injuries. I provide suggestive evidence that tickets have a larger impact at night and on female drivers.