Pierre Pestieau is Professor Emeritus of Economics at University of Liege, Belgium. He is also a member of CORE, Louvain-la-Neuve, associate member of PSE, Paris, and CESIfo Fellow. Previously, he has taught at Cornell University. His major interests are pension economics, social insurance, inheritance taxation, and redistributive policies. His books include Social Security and Retirement (MIT Press, 2005) and The Welfare State in the European Union (Oxford University Press, 2005). Mathieu Lefebvre is an Associate Professor at the University of Strasbourg, where he is a member of the Bureau d'Economie Théorique et Appliquée. Previously, he has held positions at the University of Lyon and the University of Montpellier. His research is in the areas of public economics, labour economics and behavioural economics and includes, among others, the evaluation of labour market policies towards the elderly, the performance of social protection and the poverty measurement at old age.