Subperfect Game: Profitable Biases of NBA Referees


  • We thank Eric Millis for suggesting the title, two anonymous referees, the Co-Editor, Michael Pang, Joe Harrington, Patrick Emerson, Joshua Price, Dave Berri, and Ryan Rodenberg (especially) for helpful comments, and Henry Tappen for excellent research assistance. The views expressed herein are entirely those of the authors and should not be purported to reflect those of the U.S. Department of Justice.


This paper empirically investigates three hypotheses regarding biases of National Basketball Association referees. Identification of basketball referee bias is typically difficult as changes in observed statistics may be caused by either changes in referee bias or player behavior. We identify bias by exploiting the fact that referees have varying degrees of discretion over different types of a particular statistic-turnovers. This allows us to conduct a treatment and control-style analysis, using the less discretionary turnovers as the player behavior control. The results provide evidence that referees favor home teams, teams losing during games, and teams losing in playoff series. All three biases are likely to increase consumer demand.