More discrimination in sports

This time in baseball. Very much looking forward to reading the whole paper. The Sports Economist tips us to the main results from the paper's FAQs.

1. What are the main results of the study?
There are three. First, umpires are more likely to call strikes for pitchers who share their race/ethnicity. The second result is an extension of the first: Umpires are more likely to express a preference for their own race/ethnicity only when their behavior is less closely scrutinized: 1) in parks where QuesTec (a computerized system set up to monitor and review an umpire’s ball and strike calls) is not installed, 2) in poorly attended games, and 3) on pitches where the umpire’s call cannot determine the outcome of the at-bat. Finally, game outcomes are influenced by the race/ethnicity match between starting pitchers and home-plate umpires. Home teams are more (less) likely to win a game when their starting pitcher and home plate umpire have the same (a different) race/ethnicity.

I don't doubt that there may be discrimination in MLB. At the same time, I worry about publication bias. I mean, with this study and the NBA study, it really leads you to believe that racism probably pervades all of sports officiating. That's two out of two, right? (Actually, neither are published in a journal yet but both have received considerable attention--you know what I mean.) I'm sure there are more studies on the way, for the NFL at the very least. Someone should do a comprehensive study of soccer leagues as well since so many countries have leagues--it would be interesting to see how the results differ across countries and continents. In any case, hopefully we'll hear about such papers regardless of the result.