The Impact of Legalized Sports Betting on Aggression.

This article examines the impact of legalized sports betting in the United States on crime rates, using incident-level data from the National Incident-Based Reporting System (NIBRS) between 2017 and 2021 and employing a difference-in-differences methodology. Following the 2018 Supreme Court decision in Murphy v. National Collegiate Athletic Association, which allowed states to legalize sports betting, the study finds a significant increase in crimes—particularly assaults, larceny, and vehicle theft—occurring from the start of games to four hours after their conclusion in states that introduced legal sports betting markets. The effect is most pronounced during home games with unexpected outcomes and extends as spillover effects into neighboring states without legalized sports betting. Mechanism analyses suggest that early betting-related aggression was primarily driven by financial stress from unexpected losses, while post-pandemic aggression also involved non-financial emotional factors such as anxiety and frustration related to betting outcomes. The findings highlight important social costs associated with legalized sports betting and underscore the need for proactive policies to mitigate related harms.