El Retorno de la Parcialidad Arbitral

This study quantitatively analyzes the statistical normality of refereeing decisions (penalties, direct red cards, and yellow cards) in the five major European leagues during the 17 seasons between 2001-2002 and 2017-2018. This period coincides chronologically with documented payments made by FC Barcelona to companies owned by José María Enríquez Negreira, then vice-president of the RFEF's Technical Committee of Referees (CTA). By constructing a Composite Index of Refereeing Anomalies (ICA) validated against playing-style confounds and applying non-parametric tests (Mann-Whitney and Fisher's combined probability test) along with linear regression models with fixed effects for each team and season, a severe anomaly favoring FC Barcelona is identified. Fisher's exact test yields a cumulative p-value of 0.00027, confirming the extreme statistical significance of the phenomenon compared to pure chance. The counterfactual model estimates a net competitive benefit for the club ranging from 6.8 to 11.6 points per season, with a central scenario of 9.2 points on average. Finally, the external validation of the model using the case of Juventus (2001-2006) and the identification of a structural break in the subsequent period (2018-2023)—where FC Barcelona's refereeing indicators immediately steadily converge toward the mean of the broader pool of clubs after the cessation of payments—robustly support the hypothesis of a systematic anomaly linked to FC Barcelona's capture of the regulatory institutional framework.