¹OECD, Social Policy Division

^*The author was with the Social Policy Division of the OECD when this article was prepared. He thanks the network of experts from national public and academic institutions who have helped with the study, colleagues from the Secretariat for useful discussions and exchange of information: Manfred Huber, Howard Oxley and Peter Scherer. The views expressed here are the author's sole responsibility and do not represent those of the Organisation or its member countries. The author also thanks Veronique De Fontenay for her wonderful research assistance.