1975.
Academic Visitor, International Institute of Management, Science Center, Berlin, Germany.

1976.
Consultant to the Bank of Greece and the Secretariat of the Commission for Control of Prices of Imports and Exports, Greek Ministry of Coordination. Report: ``Sectoral Ranking Criteria for the Greek Economy, Foreign Investment, and Transfer of Foreign Technology," November, 1976 (in Greek).

1977-1978.
Consultant, Greek Ministry of Transport and Communication: Feasibility Study for the Financing and Management of the New Athens International Airport.

1979.
Academic Visitor, Engineering-Economic Planning Group, Federal Institute of Technology, Zurich.

l982.
Consultant, Ministry of National Economy and Center for Planning and Economic Research, Republic of Greece. Report: ``Public Investment Financing and Social Risk Allocation."

1981-1984.
Member, Executive Board, Modern Greek Studies Association.

1983-1984.
Member, Scientific Advisory Board, Center for Planning and Economic Research, Athens, Greece.

l984-1986.
Project Director, Family Labor Supply and Labor Force Dynamics in the Greek Economy, Center for Planning and Economic Research, Athens, Greece.

1984-1986.
Member, Board of Directors, Center for Economic Research, Athens University of Economics and Business, Athens, Greece.

1987.
Member of Program Committee, Econometric Society European Meeting, Copenhagen, Denmark, 1987.

1990-1991.
Member of the Scientific Committee, 47th Congress of the International Institute of Public Finance, was to be held in Leningrad, USSR, August 26-29, 1991, cancelled due to the coup.

1991-1992.
Member of the Program Committee, 10th World Congress of the International Economic Association Moscow, August 1992.

1990-present.
Associate Editor, Regional Science and Urban Economics.

1990-1995.
Coordinator, and 1995-1997, Member, Faculty Selection Committee for Economics, University of Cyprus.

1991-present.
Member, Academic Board of Trustees, Athens Institute of Economic Policy Studies (IMOP), Athens, Greece.

1996.
Guest Editor,Regional Science and Urban Economics, special issue on Urban--Regional Structure and Economic Growth.

1994.
Consultant. Directorate General on Regional Policy, Commission of the European Communities, Brussels.

1996--1997.
Consultant, U.S. Department of Housing and Urban Development. "Mixed-Income Housing."

1998--2000.
Member, Scientific Board, Foundation for Economic and Industrial Research, Athens, Greece.

1999--2000.
Consultant, European Regional Development, European Investment Bank, Luxembourg.

1996--1997.
Consultant, Institute for Research on Poverty, University of Wisconsin - Madison and The John D. and Catherine T. MacArthur Foundation. "Spatial Aspects of Inequality in the United States."

1998--2005.
Member, Research Network on Social Interactions and Economic Inequality, The John D. and Catherine T. MacArthur Foundation. Co-chair, Fellowships for Younger Scholars,1999--2005.

2002--
Co-organizer of annual Conferences on Research on Economic Theory and Econometrics (with Costas Azariadis, Harris Dellas, Nikos Vettas, Apostolis Philippopoulos and Emmanuel Petrakis).

2004--2008.
Associate editor, The New Palgrave Dictionary of Economics, second edition, Palgrave McMillan.

2005--
Co-chair, Greek Study Group, Center for European Studies, Harvard University.