The rapid spread of legal sports betting across the United States is being linked to a troubling side effect: noticeable spikes in violent and impulsive crime during and shortly after major sporting events.
A new study examining crime data from 2017 to 2021 finds that states which legalized sports betting following the 2018 Supreme Court decision in Murphy v. NCAA experienced sharp increases in assaults, larceny, and vehicle theft on professional game days. The rise was especially pronounced when games produced unexpected outcomes, such as underdog victories or last-minute losses.
“What surprised us most was that the increase in crime isn’t limited to states that legalize sports gambling,” said Hua Gong, assistant professor of sport analytics at Rice University. “Even neighboring states that do not allow betting see more crime on game days, likely because people travel to place bets and then return home.”
The research was co-authored by Gong and Wenche Wang, who led the study while serving as an assistant professor of sport management at the University of Michigan. Wang is now an economist in the energy sector.
“It is also worth noting that aggression may not stem solely from financial stress, as often observed in other forms of betting,” Wang said. “We find recent evidence of increased crime associated with stressful games, such as those with close or tied scores throughout as well as games that extend into overtime.”
According to the findings, crime increased by roughly 30 to 70 percent from the start of games through four hours after they ended in states with legalized betting. Assaults showed the steepest rise, jumping as much as 93 percent following unexpected home team outcomes. The study also identified spillover effects in nearby states where sports betting remains illegal.
“Sports gambling is exciting for fans and financially attractive for states, but our findings show it can also lead to more crime,” Gong said. “When people lose their bets or go through very stressful game moments, that emotional volatility can translate into aggressive behavior.”
The study, titled The Impact of Legalized Sports Betting on Aggression, appears in the Journal of Sports Economics. With sports betting now legal in 38 states, Washington, D.C., and Puerto Rico, the researchers urge policymakers to weigh tax revenue against potential social costs and consider stronger safeguards as the industry continues to grow.
