Further Examination of Potential Discrimination Among MLB Umpires

We address potential racial bias by Major League Baseball umpires with respect to ball–strike calls. We offer a number of econometric specifications to test the robustness of the results, adding the role of implicit and explicit monitoring as well as pitch location. Our analysis shows mixed results regarding the matching of umpire and pitcher race. We conclude that evidence of own-race bias is sensitive to specification and methodology. How results can differ based on different data sets, specifications, time periods, and race classifications are discussed.