1. Associate Professor of Economics, University of Toronto, and Research Scholar, Canadian Institute for Advanced Research, both in Toronto, Canada and Faculty Research Fellow, National Bureau of Economic Research, Cambridge, Massachusetts.
2. Professor of Economics, Norwegian School of Economics and Business Administration, Bergen, Norway; International Research fellow, Center for the Economics of Education, London School of Economics, London, United Kingdom, and Research Fellow, Institute for the Study of Labor (IZA), Bonn, Germany.