Sijbren Cnossen is Academic Partner of CPB Netherlands Bureau for Economic Policy Analysis and Professor of Economics at the University of Pretoria. He is Emeritus Professor Erasmus University Rotterdam and the University of Maastricht. He has held appointments at the Law Schools of Harvard University, New York University, the University of Florida, the College of Europe at Bruges, and the Netherlands Institute for Advanced Studies (NIAS). He is the (co-)author of several books and numerous articles on the design and economics of taxation. He is past editor of International Tax and Public Finance and De Economist. As a consultant to the IMF, World Bank, South African Treasury, OECD, EU Commission, USAID, and HIID, he has advised more than 30 countries on the design and reform of their tax systems, most recently Zambia and Aruba. Bas Jacobs is Professor of Public Economics at Erasmus School of Economics. He is an internationally renowned specialist in public finance. He has published on optimal income and commodity taxation, taxation of human capital and education finance, environmental taxation, and the marginal cost of public funds. In recent research, he studies the political economy of income taxation, optimal redistribution with minimum wages and labor unions, optimal policy with technological change, and optimal macro-economic stabilization policy. He has been a visiting fellow of, among others, the universities of Chicago, Munich, California at Berkeley and the Netherlands Institute for Advanced Study, and a consultant to the World Bank and the IMF. He is an influential contributor to the Dutch economic policy debate. He has written dozens of applied policy articles in national economics journals, a book on optimal income redistribution, and hundreds of opinion articles in newspapers, magazines, and blogs.