Worlds of compliance: Why leading approaches to European Union implementation are only 'sometimes-true theories'

This article summarises the main theoretical findings of a large-scale qualitative project on the transposition, enforcement and application of six European Union labour law Directives in 15 Member States. Focusing on the transposition stage, its argument starts from a theoretical puzzle: When confronting the empirical results from the 91 cases covered in the article with the various hypotheses derived from the literature, it turns out that all causal conditions suggested by existing theories, and even two of the most prominent hypotheses (on misfit and veto players), have at best rather weak explanatory power. On closer inspection, these qualitative studies show that even their basic rationale does not hold in some groups of countries. As a solution, this article offers a typology of three worlds of compliance, each of which is characterised by an ideal-typical transposition style: a 'world of law observance', a 'world of domestic politics' and a 'world of transposition neglect'. This typology provides the key to understanding when and how individual theoretical propositions are relevant.