1. Researching interest group Politics in Europe and êlsewhere: much we study, little we know? / Jan Beyers, Rainer Eising and William Maloney -- 2. Opportunity structures in the EU multi-level system / Sebastiaan Princen and Bart Kerremans -- 3. "Enlargement waves" and interest group participation in the EU policy-making system: establishing a framework of analysis / Spyros Blavoukos and George Pagoulatos -- 4. Clientelism, committees, pluralism and protests in the European Union: matching patterns? / Rainer Eising -- 5. Policy issues, organisational format and the political strategies of interest organisations / Jan Beyers -- 6. Interest groups in the European Union: how powerful are they? / Andreas Dür -- 7. The European interest system in comparative perspective: a bridge too far? / David Lowery, Caelesta Poppelaars and Joost Berkhout -- 8. Converging perspectives on interest group research in Europe and America / Christine Mahoney and Frank Baumgartner -- 9. Interest groups and democracy in the European Union / Sabine Saurugger -- 10. Conclusion: Embedding interest group research / Jan Beyers, Rainer Eising and William Maloney.