Henrik Horn is Professor of International Economics at the Institute for International Economic Studies of Stockholm University, Sweden. He has previously worked for the Economic research and Analysis Division of the world Trade Organisation, and has been a judge in the Swedish Market Court (supreme court for competition law). He is a member of the Editorial Board of the World Trade Review and is a member of the Centre for Economic Policy Research (CEPR). Petros C. Mavroidis is Professor of Law at the University of Neuchatel, Switzerland. He was previously Chair of Competition Law, European University Institute, Florence and a member of both the legal affairs division of the World Trade Organization and the Centre for Economic Policy Research (CEPR). He is Associate editor of the Journal of World Trade and a member of the Editorial board of the World Trade Review, Columbia Journal of Transnational Law, and Columbia Journal of European Law.