How do institutional constraints affect judicial decision-making? The European Court of Justice’s French language mandate

Under what conditions do the institutional features of courts affect the efficiency of judicial decision-making? Examining the Court of Justice of the European Union’s mandate that all judgments be written in French, I argue that francophone judges—i.e. judges from France, French-speaking Belgium, and Luxembourg—write judgments more efficiently than their non-francophone counterparts. Leveraging the institutional feature of the judge-rapporteur and using matching methods, I show that comparable cases with a francophone judge-rapporteur are a month shorter on average than cases with a non-francophone judge-rapporteur. This estimate is robust to scaling the judgments by their word counts. Although I provide evidence francophones write judgments with lower lexical diversity on average than non-francophones, existing empirical measures are limited in examining differences in judgment quality. These findings have implications for the efficient processing of cases at the Court of Justice and the potential consequences of adopting a lingua franca in the European Union.