The present report makes an overview of the progresses made so far in Work Package 5. At this initial stage, the main aim was to develop a new coding for core state powers in EU legislation. Such coding serves the purpose of expanding EUDIFF1 through new information on core state powers integration. The report is structured as follows: after a brief introduction, Section I presents a tripartite categorization of core state powers modes of integration. Section II tests the plausibility of the proposed categorisations through an empirical analysis that explores primary legislation from 1952 to 2016. Section III discusses the possibility of a more fine-grained distinction
