It is obvious and has been argued throughout the book that the effect of EU social policy Directives depends on timely and correct implementation in the member states. This chapter will briefly outline which instruments the EU Commission can use to make non-compliant member states fulfil their European duties. The aimis to assess the phenomenon empirically and to confront the occurrence of relevant failures with the Commission's enforcement policy.

State of the art

Within the field of research on the EU, a number of authors have dealt with the question of how well member states follow their commitment to implement EU law. Generally speaking, these studies can be divided along two lines, i.e. the approach taken and the data used. Thus most of the literature could easily be sorted into a four-box matrix, where the x-axis distinguishes between quantitative and qualitative studies, and the y-axis differentiates between cases where the initiative lies with an individual complainant or with the European Commission.