Tito Boeri holds a Ph.D. in Economics from New York University; he has been senior economist at the OECD from 1987 to 1996. Currently he is Professor of Economics at Bocconi University, Milan. Axel Borsch-Supan is Director of the Mannheim Research Institute for the Economics of Aging. He received a Ph.D. from MIT and taught at Harvard's Kennedy School of Government before he moved back to Germany. Agar Brugiavini is Professor of Economics at the University of 'Ca'Foscari' of Venice, Italy. She obtained a Ph.D. in Economics at the London School of Economics, United Kingdom and was recently awarded a Fulbright Fellowship at Northwestern University, USA. Richard Disney is Professor of Economics at the University of Nottingham, a Research Fellow of the Institute for Fiscal Studies, London, and a Director of Axia Economics. He has acted as a consultant to OECD and the World Bank. Arie Kapteyn is a senior economist at RAND. Before that he was the director of CentER at Tilburg University and professor of economics. Franco Peracchi (Ph.D., Princeton University, 1987) is a Professor of Econometrics at Tor Vergata University in Rome.