The Cost of a Bet After PASPA

My research examines this question by studying bookmaker “margins,” the built-in cost that bettors pay on every wager. Despite margins being a core component of how sportsbooks generate revenue, they have received relatively little academic attention. I analyzed 87,584 bookmaker-sport-month observations across 610 leagues worldwide, with a focus on major international operators, such as Pinnacle. The image visualizes one of my central findings: margins rose sharply following the 2018 repeal of the Professional and Amateur Sports Protection Act (PASPA), which legalized sports betting in much of the United States. The glowing line represents the increasing transaction cost faced by bettors over time, with the bright vertical mark showing the moment PASPA was repealed. Even before legalization, margins began to climb, suggesting that anticipation, awareness, and global interest in sports betting shaped markets well beyond U.S. borders.