Abstract: | This article seeks to systematically describe and explain variation in European Union policy implementation performance across member states and directives. The analyses rely on a new and original dataset comprising comparable information about transposition delay for practically all EU social directives in Germany, Greece, The Netherlands, Spain and the United Kingdom. On the basis of nearly 300 observations, we could establish that only in 42.7 per cent of our cases did member states transpose in time; 17.5 per cent exceeded the deadline by more than two years. The analysis reveals modest variation between social policy areas, more profound cross‐country differences and strong cross‐area variations within some countries. The need for inter‐ministerial coordination and administrative inefficiency are strongly associated with transposition delay. Whether a directive is new or merely an amendment is unrelated to transposition delay. The same holds for the directive’s complexity and parliamentary involvement in the transposition process. The irrelevance of the latter factors may suggest that member states anticipate some potential challenges to transposition performance and act to mitigate them. Whether and why this is the case merits further research. |