This book is the result of a collaborative European research project. After first ideas to organise a joint project on the convergence of environmental policies had been put forward at a ‘tapas’ bar in Barcelona in autumn 2000, seven political scientists at five universities participated in the common endeavour: Christoph Knill (University of Jena, and later on, Konstanz, coordination), Katharina Holzinger (Max Planck Institute for Research on Collective Goods Bonn, and later on, University of Konstanz), Martin Jänicke and Helge Jörgens (Free University Berlin), Bas Arts (University of Wageningen) and Duncan Liefferink (University of Nijmegen) and Andrea Lenschow (University of Salzburg and later on, Osnabrück). In a series of very inspiring, enjoyable and sometimes exciting meetings – one of them took place on 11 September 2001 – this group developed a joint research design and a proposal under the Fifth Framework Programme of the European Commission.

Under this programme, our research was supported by the RTD programme ‘Improving the human research potential and the socio‐economic knowledge base’, contract no. HPSE‐CT‐2002‐00103. Funds were provided from January 2003 to June 2006. This way the initial group could be complemented by a full dozen senior and junior researchers: Stephan Heichel, Jessica Pape, Maren Riepe, Jale Tosun and Natascha Warta in Konstanz, Thomas Sommerer and Tobias Meier in Hamburg, Per‐Olof Busch in Berlin, Johan Albrecht, Jelmer Kamstra, Jeroen Ooijevaar and Sietske Veenman in Nijmegen, and Dieter Pesendorfer in Salzburg.