MARCO BUTI is currently responsible for public finances in EMU in the Directorate-General for Economic and Financial Affairs, and part time Professor at the European University Institute. He is editor and co-author of a number of books in this area.JÜRGEN VON HAGEN is Professor of Economics and Director at the Center for European Integration Studies at the University of Bonn. Previously he taught at Indiana University and the University of Manheim. He has published over 150 articles in academic journals. He has been a consultant to the European Commission, the World Bank and the IMF.CARLOS MARTINEZ MONGAY is currently head of sector in the Directorate-General for Economic and Financial Affairs, and Lecturer at the University of Zaragoza. He has published papers in academic journals and has contributed chapters to several monographs.