Interactions between courts and administrative authorities in EU competition law enforcement

The EU competition law reforms of 2004 decentralised enforcement from the European Commission to national competition authorities and national courts, while the European Commission remains central to the system. This thesis responds to a need for research into how institutions interact in this system of concurrent competences to effectively enforce the EU competition rules. It explores the constitutional consequences of the methods for ensuring coherent interpretation and effective application of the EU competition rules, through case studies on the interaction between courts and administrative authorities and between the supranational and national levels. With a focus on the role of courts, the thesis draws on the EU principle of institutional balance and the concept of interpretative pluralism. It finds that while apparently empowering (national) courts, the post‐2004 regime still limits the ambit of judicial competence in favour of administrative bodies. The European Commission can influence interpretation of the competition rules in national court proceedings as well as in the European Competition Network of competition authorities, in which the Court of Justice of the European Union has in effect handed over responsibility. In an extension of national courts’ obligation not to rule counter to a European Commission decision, forthcoming legislation proposes they should be bound by national competition authority decisions. The thesis argues that there should be more emphasis on horizontal relationships between courts, led by judges themselves. This would not only lend itself to coherent – and effective – application of competition law, but would allow courts to push back against the apparent dominance of administrative authorities in this area