Seven years ago, a couple of economists from Ivy League schools dropped a study on the NBA's head saying that its referees called more fouls against black players than they did against white players.
The original study, by Joseph Price and Justin Wolfers, was released in 2007 through the New York Times, and published in the well respected Quarterly Journal of Economics. Essentially, it found that the officiating team calls fouls against black players more frequently than it does against white players. Its findings, it said, were small but significant. Over the course of a year, two identically talented teams, one made up of all white players and the other all black players, would see enough calls swing to project the white team winning about two more games, though of course the effect is far more subtle in real life.
David Stern and the NBA called horseshit basically as soon as they read the headline (discrimination lawsuits are expensive!), fundamentally misunderstanding that the finding wasn't about any intentional or structural agendas, but the intricate ways that humans interact with other humans who aren't exactly like themselves. So the league published its own paper attempting to refute the claims, but sort of confirming them instead, only this time with more robust and granular data. Other studies would soon follow, seeing similar effects in places like the strike zone in baseball.
But that was several years ago at this point. Now Price and Wolfers have taken another swing at the numbers. If the first study's results were really an aberration in the way play in the league happens, they reasoned, then it should be the same now as then, and something besides a small bias could be the reason. Instead, it found the bias has been all but eradicated. Below is a chart put together by the Washington Post, displaying the differences.
These new findings do two things. They show that, first of all, the NBA has done a great job in stamping out a small but noticeable bias. They also show that the bias existed and was correctable. The league says that it did "absolutely nothing" differently, which might be true, or might not. But even if it is, the refs surely saw the study, and probably did a some self-evaluation to see if there was anything they could do to address a big-data bias in their work.
And so, a small racial bias is no more, mainly because we talked about it.