JULIAN LE GRAND is the Richard Titmuss Professor of Social Policy at the London School of Economics. He is a leading expert on public and social policy and acted as a senior policy advisor to the Prime Minister between 2003 and 2005. He is the author, co-author or editor of seventeen books and over ninety articles on economics, philosophy and public policy. CAROL PROPPER holds professorships at the University of Bristol, where she co-founded the Centre for Market and Public Organisation, and at Imperial College, London where she heads the new Healthcare Management Group. She specializes in the economics of healthcare provision markets, particularly the role of incentives, and has published extensively in economics and professional journals. SARAH SMITH is Senior Research Fellow at the Centre for Market and Public Organisation at the University of Bristol. She has previously worked as an economist at HM Treasury, the Financial Services Authority and the Institute for Fiscal Studies. Her work centres on the microeconomic analysis of public policy and she has published widely in economics and policy journals.