In this paper Markus Jachtenfuchs, Philipp Genschel, Marta Migliorati, and Franziska Loschert study two areas of Core State Powers (CSP), i.e. the EU budget and Justice and Home Affairs. The two cases have the aim to reconstruct how Differentiated Integration (DI) has developed over time in these two specific domains. While the aim is the same for both cases, the way the cases are structured is substantially different. This is due to various reasons. First, the politics of the EU budget go back to the early days of the EU, while JHA is a post-Maastricht feature. This implies that the budget case study concentrates on a much longer time span. Second, DI in the budget interests several member states, while in JHA it is a phenomenon circumscribed to fewer members. Finally, the politics of the budget are decided through intergovernmental negotiations, while JHA is a rather supranationalised policy that relies a lot on secondary legislation and EU executive bodies such as EU agencies.
Markus Jachtenfuchs, Philipp Genschel, Marta Migliorati, and Franziska Loschert. 2022. Differentiated integration and core state powers: The EU budget and Justice and Home Affairs. European University Institute.