On December 4, 2009, the MPIfG marked its twenty-fifth anniversary with an official celebration at the Wallraf-Richartz-Museum in Cologne for some 180 guests. Professor Andreas Pinkwart, Minister for Innovation, Science, Research and Technology for North Rhine-Westphalia, welcomed the audience, as did Thomas Rachel, the Parliamentary State Secretary of the Federal Ministry of Education and Research, Jürgen Roters, the Mayor of the City of Cologne, Professor Thomas Krieg, the Prorector of the University of Cologne, and Professor Christine Musselin, Director of the Centre de Sociologie des Organisations at the Sciences Po, Paris. In his address, Max Planck Society President Peter Gruss acknowledged the efforts of Founding Director Renate Mayntz and Fritz W. Scharpf in developing the institute and noted that today the MPIfG is recognized and respected around the world. Past and present directors of the Institute - Jens Beckert, Renate Mayntz, Fritz W. Scharpf und Wolfgang Streeck - spoke about the MPIfG’s current research focus in a panel discussion entitled, "The Governance of Society: Politics versus Markets?". At the reception hosted by Mayor Jürgen Roters afterward at the Cologne City Hall, the institute’s directors and and directors emeritus signed the guest book of the city.