Legal sports betting linked to sharp increases in violent crime, study finds

As legalized sports betting sweeps across the country, new research shows the policy shift comes with a hidden public safety cost: a measurable rise in violent and impulsive crime on game days.

“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 study, co-authored by Gong and Wenche Wang, analyzed crime incident data from 2017 to 2021 and finds that states that legalized sports betting after the 2018 Supreme Court decision in Murphy v. NCAA saw significant increases in assaults, larceny and vehicle theft during and immediately following professional sports games. Crime levels rose the most when betting outcomes defied expectations, e.g., when underdogs won.

Wang led the research while an assistant professor of sport management at the University of Michigan and is now an economist in the energy industry.

“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.”

“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, “The Impact of Legalized Sports Betting on Aggression,” appears in the Journal of Sports Economics.

Key findings

• Crime increases 30-70% from the start of a game through four hours after its conclusion in states that legalized sports betting with the largest increases tied to home games and unexpected outcomes.

• Assaults see the largest jump — up to 93% after unexpected home team outcomes.

• Spillover effects appear in neighboring states even when those states have not legalized betting.

• After the pandemic, the mechanism driving betting-related aggression appears to shift from primarily financial stress to nonfinancial factors, particularly the stressfulness of the game itself, as bettors increasingly wager on more unpredictable contests.

Growing national issue

Sports betting is now legal in 38 states plus Washington, D.C., and Puerto Rico, and generates billions in tax revenue. But Gong says policymakers need to understand the tradeoffs.

“Legal betting brings in revenue, but there are serious social consequences we cannot ignore,” Gong said. “Lawmakers should consider safeguards, better consumer protections and public awareness efforts as the industry continues to expand.”