The Sensitivity of Findings of Expected Bookmaker Profitability

Levitt (2004) demonstrates that, contrary to conventional wisdom, sports books may not try to balance the money wagered on the sides of a game but instead exploit preferences of bettors in order to maximize expected profits. Levitt's findings are based on unique data from a wagering contest of the 2002 NFL season. Reconsideration based on 2004-2010 data from a similar contest yields findings of a dramatically smaller increase in expected profitability from strategic line making. Additionally, the traditional underperformance of favorites in athletic wagering may have somewhat subsided which would also imply reduced bookmaker profits compared to those Levitt reports