Seven years ago, a pair of scholars released a study of NBA referees (pdf) that found white officiating crews more likely to call fouls against black player—and, to a lesser degree, black officiating crews more likely to call fouls against white players. The study drew broad media attention and caused a small stir in the league. Then-Commissioner David Stern, questioned its validity in the New York Times, and players weighed in on sports-talk radio and ESPN.
The same scholars, Justin Wolfers of the University of Michigan and Joseph Price of Brigham Young University, returned to the subject of racially biased referees in a working paper released in December with an astounding result. Once the results of the original study were widely known, the bias disappeared. “When we conduct the same tests for own-race bias in the period immediately following the media coverage,” they wrote, “we find none exists.”
The original data set came from the 1991-2002 NBA seasons. In the new study, in which the original scholars worked with Devin Pope of the Booth School of Business, the authors looked both at a sample from the 2003-2006 seasons—after the original data but before the public attention—and from 2007-2010. From 2003 to 2006, the bias persisted at the same level, roughly an extra fifth of a foul every 48 minutes. But from 2007 to 2010, they found no significant bias in either direction.
In explaining why this happened, the authors argue that public awareness itself shaped referee behavior. The NBA, they wrote, did not increase the frequency of mixed-race officiating crews or otherwise take action after the release of the initial study:
A phone conversation with NBA league administrators who oversee the NBA’s officiating department suggests that that NBA did not take any specific action to eliminate referee discrimination. Specifically, the administrators to whom we spoke denied that the NBA spoke with the referees about the Price and Wolfers study. They also indicated that the study did not lead to a change in referee incentives or a change in the way they train their referees.
Simply knowing that bias was present and that other people knew, they wrote, made it go away:
We argue that this dramatic decrease in bias is a causal result of the awareness associated with the treatment—the release and subsequent publicity surrounding the original academic study in 2007.
The study may hold implications for any organization looking to reduce group bias. In the realms of public policy and education, the focus is often on increased exposure and proximity to out groups. But bias, as the original referee study showed, can sometimes withstand proximity. The remedy might be to locate bigotry and bring it into the light. As Louis Brandeis famously wrote in 1913: “Publicity is justly commended as a remedy for social and industrial diseases. Sunlight is said to be the best of disinfectants; electric light the most efficient policeman.”