National, partisan or ideological biases? How EU officials' characteristics can influence infringement proceeding outcomes

Infringement proceedings serve as a key legal mechanism through which the European Union (EU) enforces compliance with common laws among its member states. This article, for the first time, examines how the nationality and partisanship of EU officials influence outcomes of these proceedings. We argue that Commissioners and Directors-General face a principal–agent dilemma, as they simultaneously act as EU officials and as nationals of their home countries. We expect that infringement proceedings are less likely to escalate when they are overseen by EU officials who share the nationality of the member state under investigation. We further posit that officials' partisan affiliations and ideological leaning may shape the outcomes of such cases. Using a novel dataset combining roughly 19.000 infringement proceedings between 2002 and 2020 with information about the responsible officials, we find evidence of a nationality bias, however, only among Commissioners. By contrast, we find no indication of bias linked to ideology or partisanship.