Differentiated European integration (EUDIFF1 & EUDIFF2)

The EUDIFF1 dataset codes differentiation in EU treaties from 1952-2020. The EUDIFF2 dataset codes differentiation in EU legislation from 1958-2018. These datasets have not been released publicly yet. Please contact me or the other authors for information. The data collection was funded by the German Research Foundation (DFG) and the Swiss National Science Foundation (SNSF) (project leaders: Katharina Holzinger and Frank Schimmelfennig).

For articles introducing and analyzing these datasets, see Schimmelfennig and Winzen (2014) and Duttle et al. (2017). For a broader study of differentiated integration as well as analyses of the most recent versions of EUDIFF1 and EUDIFF2, see Schimmelfennig and Winzen (2020).

• Duttle, Thomas, Katharina Holzinger, Thomas Malang, Thomas Schäubli, Frank Schimmelfennig, and Thomas Winzen. 2017. ‘Opting out from European Union Legislation: The Differentiation of Secondary Law’. Journal of European Public Policy 24 (3): 406–28. https://doi.org/10.1080/13501763.2016.1149206.
• Schimmelfennig, Frank, and Thomas Winzen. 2014. ‘Instrumental and Constitutional Differentiation in the European Union’. Journal of Common Market Studies 52 (2): 354–70. https://doi.org/10.1111/jcms.12103.
• Schimmelfennig, Frank, and Thomas Winzen. 2020. Ever Looser Union? Differentiated Integration. Oxford: Oxford University Press.