Is the NFL betting market still inefficient?

Abstract

In this paper, I examine market efficiency in the National Football League betting market. In the point spread market, sportsbooks appear to underestimate the abilities of the home team as they are more likely to cover the spread when they are a substantial underdogs and when the home team has not covered the spread in its previous games. In the totals market, games are more likely to cover the over when the closing line is small or large showing a quadratic relationship to game outcomes and when the home team has covered the over in its previous games. Overall, the results show that both the point spread and totals market are statistically inefficient.