From 2001 to 2004 he was economic adviser to European Commission President Romano Prodi. As such, he was the coordinator of the landmark report on Europe's growth policy known as the Sapir Report.[2] He then served until 2009 in the group of Economic Policy Advisors to Prodi's successor José Manuel Barroso.
A European Mechanism for Sovereign Debt Crisis Resolution: A Proposal, Bruegel Blueprint No. 10, Bruegel, Brussels, 2010 (with François Gianviti, Anne Krueger, Jean Pisani-Ferry and Jürgen von Hagen). ISBN978-9-078910-18-3
Economic Policy in EMU, Oxford University Press, Oxford, 1998 (co-authored and co-edited with Marco Buti). ISBN0-19-829477-8 (Italian translation published by Il Mulino, Bologna, 1999)