Assessing the Impact of EU Legislation on the Member States. A Legal Perspective based on the Notion of National Discretion

How does EU law impact its Member States? The question is as politically sensitive as it is difficult to answer. It is a politically sensitive issue as it concerns how the EU affects national sovereignty. Quantitative research has, however, not delivered an equivocal answer. Instead, it has produced highly diverging conclusions which may be explained from the differing methods that have been applied. This paper argues that a legal approach is key to understanding the impact the EU has on the Member States. Thus far, however, the legal contribution to the understanding of the relation between the EU and its Member States has been mostly limited to the elaboration of the principles of conferral, subsidiarity and other relevant constitutional principles. Guided by the notion of ‘national discretion’ this paper will explore how EU legislation leaves policy choices and other room for manoeuvre to the Member States. Examples may be the inclusion of open norms, the possibility to apply exceptions at the national level or the limitation of the scope of application of EU law (e.g. to transnational situations). It compares three distinct areas of EU law: immigration law, freedom to provide services and criminal law. The objective of this paper is thus to come to a better, and a more refined, understanding of the relation between the EU and the Member States