ARE NBA OFFICIALS PREJUDICED?
he sports page of the May 2, 2007, edition of the New York Times
contained the headline: “Study of NBA Sees Racial Bias in Calling Fouls.”1
article was based on a study by Cornell professor Joseph Price and Wharton
professor Justin Wolfers.2
Price and Wolfers (PW) claim that “more personal fouls are called against players when they are officiated by an oppositerace refereeing crew than when officiated by an own- race crew.” In this
chapter we discuss their insightful analysis of the referee bias question.
What Are the Best Data to Use
to Test for Referee Bias?
An NBA officiating crew consists of three officials. The ideal way to determine whether the racial composition of the officiating crew influences
the rate at which fouls are called against whites and blacks would be to look
at a set of NBA games and determine the rate at which black officials and
white officials call fouls on white and black players. The data might look
something like the 1,000 games of data excerpted in figure 34.1. For each
game in figure 34.1, we can classify each foul into one of four groups:
|• ||a black official calling a foul on a black player|
|• ||a white official calling a foul on a white player|
|• ||a white official calling a foul on a black player|
|• ||a black official calling a foul on a white player|
A 1 in columns E–G denotes a white official, while a 0 in columns E–G
denotes a black official. For example, in game 1 there were one white and
1 This article is available at http://www.nytimes.com/2007/05/02/sports/basketball/02refs
2 Price and Wolfers, “Racial Discrimination among NBA Referees.”