- Professor of Economics, University of East Anglia
- Deputy Director, Center for Competition Policy
- Fellow, Georgetown Center for Economic Research
- Permanent Visiting Professor, Düsseldorf Institute for Competition Economics (DICE), Heinrich-Heine Universität Düsseldorf.
- Research Fellow, Center for Economic Policy Research (CEPR), London. (February 1996 - )
- Bonn University, West Germany. Study of Economics (September 1984 -August 1987). Vordiplom in Economics (October 1986)
- London School of Economics and Political Science, UK. (September 1987 - July 1988). MCs in Economics, August 1988.
- Nuffield College, Oxford University, UK. (October 1988 - August 1991). D.Phil in Economics, November 1991. Thesis: "Principal-Agent Problems and Commitment in Imperfectly Competitive Markets". (Thesis Advisor: Prof. John S. Vickers)
- Member, Executive Committee, European Association for Research in Industrial Economics (EARIE)
- Member, Board of Directors, Center on Regulation in Europe (CERRE)
- Member, Board of Advisors, Global Antitrust Institute, Law Economics Center, George Mason University Law School
- Member, Scientific Advisory Committee, Düsseldorf Institute for Competition Economics, University of Düsseldorf, Germany.
- Member, Scientific Advisory Committee, Forschungsinstitut für Wirtschaftsverfassung und Wettbewerb (FIW), Cologne, Germany Member, International Committee, Concurrences - Journal of Competition Laws
- Member, Editorial Board, Rivista Italiana di Antitrust/Italian Antitrust Review
- Member, Editorial Board, Journal of Industrial Economics
- Editor, Journal of Industrial Economics (July 2008 - April 2011)
- Director of PhD Admissions, Department of Economics, University of Michigan, 2010 - 2012
- Director of Engagement and Impact, School of Economics, University of East Anglia, 2016 -
- Academic Advisor, The Brattle Group (January 2019 -)
- Senior Consultant, CRA International (October 2013 - December 2018)
- Consultant, Amazon, (November 2015 - )
- Senior Academic Advisor, CRA International (European Competition Practice) (formerly Lexicon Ltd.), London, Consultancy for competition policy and regulation cases (1995 - 2011). (Projects advised on cover these areas: collusion, mergers, marker definition, intellectual property rights, regulation of telecommunications and postal services, exclusionary conduct, price discrimination, information exchange, tying arrangements, aftermarkets, vertical market arrangements, joint dominance).
- Expert, Applied Economics Consultants (2008 - 2011) (antitrust litigation)
- Academic Consultant for London Economics, London, on the projects "Single Market Review 96: Competition Issues" and "Report to the Italian Electricity Authority on Regulatory Reform in the Electricity Industry. Country Study: Spain". (1994)
- "Financial Constraints and Moral Hazard: the Case of Franchising", (with Y. Fan and F. Lafontaine), Journal of Political Economy,
- "Communication and Cooperation: A Methodological Study", (with D. Cooper), Southern Economic Journal, Vol. 82, pp. 1167-1185, April 2016
- "Communication, Renegotiation, and the Scope for Collusion", (with D. Cooper, Florida State University), American Economic Journal: Microeconomics, May 2014
- "How Market Fragmentation Can Facilitate Collusion", Journal of the European Economic Association, Vol. 10, pp 1116-1140, October 2012
- "Fighting Collusion by Regulating Communication between Firms", Economic Policy, 32, pp. 169-204, April 2001.
- "Excess Entry, Vertical Integration, and Welfare", The RAND Journal of Economics, Vol. 30 (4), pp. 575-603, Winter 1999. (With X. Vives, IAE, Barcelona).
- "Nonlinear Pricing in Vertically Related Duopolies", The RAND Journal of Economics, Vol. 28 (1), pp. 37-62, Spring 1997.
- "Product Line Decisions and the Coase Conjecture", The RAND Journal of Economics, Vol. 27 (2), pp. 391-414, Summer 1996. (With A.J. Padilla, CEMFI, Madrid).
- "Coase versus Pacman: Who Easts Whom in the Durable Durable Goods Monopoly?", Journal of Political Economy, Vol. 103 (4), pp. 785-812, August 1995, (With N.-H. von der Fehr, University of Oslo).