I examine outcome predictability in the National Football League totals betting market using data from the 1984 through 2004 seasons. Results suggest that while weather is an important determinant of scoring, the market does not accurately incorporate the effects of adverse conditions into...

We examine 330,857 trades of prediction market contracts, the values of which are based on against-the-spread outcomes of NFL games, and find the presence of a significant reverse favourite-longshot bias. Surprisingly, the timing of this bias is identical to that observed in traditional...

From 2000 to 2008, Tradesports operated an online betting site where gamblers used real money to wager on the outcomes of various sporting events. A critical difference between Tradesports and traditional casino-type venues is that participants were allowed to place wagers after underlying...

Prediction markets add value when they produce unbiased forecasts. However, several prior studies find persistent biases when examining prediction market sides contracts. Sides contracts represent bets on whether the score differential between two teams in a contest will be greater or less than...

This study examines the pre-game and within-game price movements of contracts listed on Tradesports to determine whether relevant information is quickly and accurately embedded into asset prices. Each contract represents a totals (over/under) bet on an NFL game. In traditional casino-style...

We test the NBA betting market for efficiency and find that totals lines are significantly biased early each season, yet sides lines do not show a similar bias. While market participants generally force line movements in the correct direction from open to close, they do not fully remove the...