From 1999 to 2008, Professor Hahn served as the director of the AEI-Brookings Joint Center, a leader in policy research in law and economics, regulation, and antitrust. Previously, he worked for the US President's Council of Economic Advisers, where he helped design the market-based cap-and-trade system for limiting smokestack sulfur emissions at minimum cost to industry. He also served on the faculties of Harvard University and Carnegie Mellon University. Professor Hahn is a frequent contributor to leading scholarly journals including the American Economic Review, Science, and the Yale Law Journal, as well as to general-interest periodicals including the New York Times and Forbes.com. He is also the co-founder of Regulation2point0.org.
Following employment at the Oxford Centre for Management Studies, Stirling University and Australian National University, Professor Ulph spent 25 years (1979-2004) at the University of Southampton, the last 20 of these as Professor of Economics, with spells as Visiting Professor at the University of British Columbia (1985), Australian National University (2002), and University of California Santa Barbara (2002). He was appointed Economic Assessor for the Hinkley Point C Public Inquiry (1989-90) and elected President of European Association of Environmental and Resource Economists (2000-2001) and Fellow of the Royal Society of Arts (2000-). Between April 2004 and 2010 he held the post of Vice-President and Dean of the Faculty of Humanities at The University of Manchester. He has published 6 books and over 100 refereed papers.