Mapping Reversals: An Empirical Account of Margrethe Vestager's Track Record Before the Court of Justice of the European Union

Margrethe Vestager concluded her second mandate as European Commissioner for Competition in November 2024. During her tenure, the Directorate-General for Competition ("DG Comp") appeared before the Court of Justice of the European Union ("CJEU") in 241 cases. This study is the first to offer an empirical analysis of Vestager's track record before the CJEU. We provide a comprehensive account of her successes and setbacks, and identify key patterns in CJEU rulings. At a macro level, our findings indicate that 27.47% of the decisions first issued under Margrethe Vestager's leadership have been at least partially overruled by the CJEU upon reaching the Court, with more cases likely to follow. When antitrust cases reach a judgment, DG Comp loses 24.6% of them over the period. Our findings also reveal surprising results at a micro level. DG Comp lost only one case before the CJEU on Article 102 over the period. None of the decisions initiated by Margrethe Vestager under Article 102 has been overruled by the CJEU to date. In merger control, only seven cases reached the CJEU during her two mandates, with just two overturned-representing 0.05% of the merger decisions she issued. Regarding state aid, the Commission lost most cases on substantive grounds rather than procedural ones. Our analysis uncovers the underlying patterns behind these cases and thus offers new insights into the judicial dynamics of EU competition law during Vestager's tenure.