Economists Find Racial Bias in NBA Refereeing
A new academic paper by Justin Wolfers and Joseph Price finds evidence of subconscious racial bias by NBA referees, although the effects are rather small:
Mr. Wolfers and Mr. Price examined whether otherwise similar black and white players had fouls-per-minute rates that varied with the racial makeup of the refereeing crew.
“Across all of these specifications,” they write, “we find that black players receive around 0.12-0.20 more fouls per 48 minutes played (an increase of 2 ½-4 ½ percent) when the number of white referees officiating a game increases from zero to three.”
Mr. Wolfers and Mr. Price also report a statistically significant correlation with decreases in points, rebounds and assists, and a rise in turnovers, when players performed before primarily opposite-race officials.
“Player-performance appears to deteriorate at every margin when officiated by a larger fraction of opposite-race referees,” they write. The paper later notes no change in free-throw percentage. “We emphasize this result because this is the one on-court behavior that we expect to be unaffected by referee behavior.”
I’m not sure exactly what to make of their findings without having read the whole paper, but an effect of 0.12 fouls per 48 minutes translates into just 13 fouls over an entire season (assuming a player is on the court every minute of all 82 regular-season games); I don’t doubt the statistical significance of their results, but a foul every 8-9 games would only be an important effect if referees were non-randomly assigned and most games had either all-white or all-black officiating crews, but neither is the case (77% of NBA games were refereed by a mixed-race crew over the period studied, which is a figure likely to increase as the number of black NBA referees is increasing). In other words, we would expect these effects to by-and-large cancel themselves out over the length of a season, even if individual games might be slightly biased by these effects.
As the Times account indicates, the study is probably a more interesting contribution to the debate over the role of subconscious/unconscious racism than it is in terms of its insight into NBA refereeing–doubtless to the disappointment of frequent ref critics like Mavericks owner Mark Cuban.