A coming paper by a University of Pennsylvania professor and a Cornell University graduate student says that, during the 13 seasons from 1991 through 2004, white referees called fouls at a greater rate against black players than against white players.
Justin Wolfers, an assistant professor of business and public policy at the Wharton School, and Joseph Price, a Cornell graduate student in economics, found a corresponding bias in which black officials called fouls more frequently against white players, though that tendency was not as strong. They went on to claim that the different rates at which fouls are called â€œis large enough that the probability of a team winning is noticeably affected by the racial composition of the refereeing crew assigned to the game.â€
The NBA clearly saw the potential for bad publicity when Price & Wolfers sent them a draft version in 2006, so they commissioned their own paper. So the New York Times did an interesting thing.
Three independent experts asked by The Times to examine the Wolfers-Price paper and materials released by the N.B.A. said they considered the Wolfers-Price argument far more sound. … The three experts who examined the Wolfers-Price paper and the N.B.A.â€™s materials were Ian Ayres of Yale Law School, the author of â€œPervasive Prejudice?â€ and an expert in testing for how subtle racial bias, also known as implicit association, appears in interactions ranging from the setting of bail amounts to the tipping of taxi drivers; David Berri of California State University-Bakersfield, the author of â€œThe Wages of Wins,â€ which analyzes sports issues using statistics; and Larry Katz of Harvard University, the senior editor of the Quarterly Journal of Economics.
(BTW, the Times made a mistake in asking Katz. While he’s a great economist, he was also one of Justin’s thesis advisers, which creates an appearance of partiality. But I don’t think there’s any such issue with Ayres or Berri.)
The Price-Wolfers analysis was based on NBA games from 1991/92 to 2003/04, so you might wonder whether the bias is still as pronounced. To answer that question, they re-run the model using 2004/05 to 2006/07 games, and find very similar estimates.
I don’t find the results at all surprising. If you were ever going to find discrimination, you’d find it in a context that forced people to make snap decisions. Don’t believe me? TryÂ the Implicit Association Test.