Through conditionality, socialisation, externalisation, and imitation, the EU generates external effects. The comparison of EU relations with "quasi-member states", candidate countries, the European neighbourhood, other OECD countries, and far-away regions shows that the mechanisms and conditions of Europeanisation vary significantly across contexts. In general, however, market power and supranational regulation are the most important conditions of effectiveness. In their absence, the EU's institutions can merely serve as an agency for socialisation and a model for imitation -albeit with a limited and superficial impact.