Justin Lindeboom is Ph.D. Researcher at the University of Groningen. He took degrees in Law and History from the University of Groningen and an LL.M. degree from University College London. He is also Fellow at the Centre for Law, Society & Economics at University College London, and has been Visiting Researcher at the Max Planck Centre of Comparative Public Law and International Law in Heidelberg (2016) and the European University Institute in Florence (2018). He writes on EU citizenship, philosophy and theory of EU law, and the foundations and informants of competition law. He is also co-editor of the Quality of Nationality Index (www.nationalityindex.com).