This chapter discusses in detail the hypotheses on the reasons for implementation success or failure which we derived from the existing literature as well asa number of new ones which we formulated on the basis of our own theoretical considerations (see Chapter 2). We argue that the ‘upstream phase’ (i.e. features of the decision-making process which leads to the adoption of a Directive) has only a limited impact on the ‘downstream phase’ of adaptation at the national level. Furthermore, we highlight the differential impact of domestic factors in EU policy implementation. The analysis reveals that no single overriding variable may account for the transposition performance of member states, but that we need to look at the interaction of several factors. As the next chapter will show in more detail, the relevant combinations of factors and the logic of their interplay vary fundamentally in different country clusters.

Implementation problems as a result of ‘opposition through the backdoor’?

According to an intergovernmentalist view of European policy-making, the preference formation processes of the lower-level polity and the higher-level polity are clearly distinct. This implies that in cases where a national government is unsuccessful in ‘uploading’ its own preferences at the EU level as the template for the joint measure or standard, it will try to resist during the ‘downloading’ process, i.e. later at the implementation stage. Hence, in those cases where there is no national objection to a specific measure during decision-making at EU level, implementation should be unproblematic.