To discriminate or not to discriminate -- Is data aggregation the question?

Previous professional sports discrimination studies rely heavily on aggregated data to the game level and therefore do not control for unobservable within game heterogeneity. This article uses an established testing methodology for assessing discrimination among professional sports adjudicators and compares inferences when data are and are not aggregated above an influential factor that affects within game foul/penalty rates. Substantial differences in conclusions are found suggesting that a number of inferences in the literature relating to discrimination in various contexts may be fragile. The issue and findings have potential relevance to a wide range of related studies.