Does Europeanization matter, and, if so, to what extent and in what respects? While research on the European Union is thriving, only limited efforts have been directed towards a discussion of this crucial question. This paper examines the outcome of the EU policy process from various comparative perspectives in an effort to distinguish the 'net effects' of EU membership and EU-level policy outcomes from more general perhaps global processes of change. The effects of EU membership are discussed in relation to the process of liberalization and the major question raised is whether Europeanization matters for the advance of liberalization. In responding to this question, the paper advances the following major argument: While the Europeanization of the telecoms and electricity industries has led to some liberalization, it is at best a mediating variable, not an independent one. The major features of liberalization would have been diffused to practically all member states even in the absence of the European Commission and other agents of supranationalism. This is not to suggest that Europeanization does not matter, but that it matters in less obvious and perhaps less critical ways than is frequently assumed. These arguments are supported by comparative empirical analysis of the spatial and temporal diffusion of liberalization across nations and sectors, and by a comparison of the diffusion of liberalization today with the diffusion of nationalization in the past.