Visiting Professor, Department of Economics, S.U.N.Y. - Binghamton, New York, USA, 1991

Research Fellow, UpJohn Institute for Employment Research, 1994

Visiting Professor, Department of Economics, University of Melbourne, Australia, 1995

Professor, Department of Economics, Southern Methodist University, Dallas, USA, 1996-2013

Professor Emeritus, Department of Economics, Southern Methodist University, Dallas, USA, 2013

Fellow, Journal of Econometrics, elected 2008

Consultant to United Nations Development Programme, 2007

Founding Editor, Research on Economic Inequality, 1989-1998

Founding Co-Editor, Journal of Economic Inequality, 2003

Associate Editor, NAFTA: The Business and Law Review of the Americas

Associate Editor, Journal of Economic Surveys, 1995-

Associate Editor, Journal of Income Distribution, 1998-2003

Associate Editor, Empirical Economics, 1998-2003

Member of Editorial Board: Review of Income and Wealth, 1993-1996

Member of Editorial Board, Journal of Informatics and Data Mining, from 2015.

Member of Editorial Board, Journal of Heath & Medical Economics, from 2015.