Thursday, May 03, 2007

NYT - Study of N.B.A. Sees Racial Bias in Calling Fouls

in case you haven't turned on espn in the last week:
Study of N.B.A. Sees Racial Bias in Calling Fouls

though i'd love to see the paper itself...
EDIT: nyc deel found it: Text of Study thank you! (i'm not highlighting that; will read later)

Highlights:

[The study] 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 “is large enough that the probability of a team winning is noticeably affected by the racial composition of the refereeing crew assigned to the game.”


“I would be more surprised if it didn’t exist,” Mr. Ayres [author of "Pervasive Prejudice?"] said of an implicit association bias in the N.B.A. “There’s a growing consensus that a large proportion of racialized decisions is not driven by any conscious race discrimination, but that it is often just driven by unconscious, or subconscious, attitudes. When you force people to make snap decisions, they often can’t keep themselves from subconsciously treating blacks different than whites, men different from women.”


But they said they continued to find the same phenomenon: that players who were similar in all ways except skin color drew foul calls at a rate difference of up to 4 ½ percent depending on the racial composition of an N.B.A. game’s three-person referee crew.


With their database of almost 600,000 foul calls, Mr. Wolfers and Mr. Price used a common statistical technique called multivariable regression analysis, which can identify correlations between different variables. The economists accounted for a wide range of factors: that centers, who tend to draw more fouls, were disproportionately white; that veteran players and All-Stars tended to draw foul calls at different rates than rookies and non-stars; whether the players were at home or on the road, as officials can be influenced by crowd noise; particular coaches on the sidelines; the players’ assertiveness on the court, as defined by their established rates of assists, steals, turnovers and other statistics; and more subtle factors like how some substitute players enter games specifically to commit fouls.


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.


Mr. Wolfers and Mr. Price claim that these changes are enough to affect game outcomes. Their results suggested that for each additional black starter a team had, relative to its opponent, a team’s chance of winning would decline from a theoretical 50 percent to 49 percent and so on, a concept mirrored by the game evidence: the team with the greater share of playing time by black players during those 13 years won 48.6 percent of games — a difference of about two victories in an 82-game season.


The N.B.A.’s reciprocal study was conducted by the Segal Company, the actuarial consulting firm which designed the in-house data-collection system the league uses to identify patterns for referee-training purposes, to test for evidence of bias. The league’s study was less formal and detailed than an academic paper, included foul calls for only two and a half seasons (from November 2004 through January 2007), and did not consider differences among players by position, veteran status and the like. But it did have the clear advantage of specifying which of the three referees blew his whistle on each foul.

The N.B.A. study reported no significant differences in how often white and black referees collectively called fouls on white and black players. Mr. Stern said he was therefore convinced “that there’s no demonstration of any bias here — based upon more robust and more data that was available to us because we keep that data.”


Both [authors of the paper] cautioned that the racial discrimination they claim to have found should be interpreted in the context of bias found in other parts of American society.

“There’s bias on the basketball court,” Mr. Wolfers said, “but less than when you’re trying to hail a cab at midnight.”

2 comments:

McChen said...

Probably the worst study I've ever heard. When the uneducated public is destroying your study's statistics and methods, you've done a terrible job. Penn/Columbia should be ashamed.

fny21 said...

haha you should've seen the "watching too much tv causes autism" paper.