Investigating the Lisbon Treaty’s Impact on the Co-citation Network of the Court of Justice of the European Union Case Law

This study examines the evolution of the Court of Justice of the European Union’s co-citation networks of precedents, before and after the entry into force of the Lisbon Treaty. By analyzing centrality metrics and clustering patterns, we uncover shifts in the structure of precedents. We introduce a novel framework based on stochastic block models to identify core clusters of precedents, i.e., those that we assume can be applied to different cases and legal domains. The results highlight the evolving nature of legal precedent in the EU, emphasizing the functional adaptability of precedents across diverse legal contexts rather than rigid doctrinal shifts.