
| since 1985 | full Professor (C4) at IMW |
| 2002-2009 | Director of IMW |
| 1984-1985 | Visiting Professor at IMW |
| 1983-1984 | Research Associate at Univ. of Bonn |
| 1983 | Habilitation Univ. of Bonn |
| 1981-1983 | DFG Habilitation Scholarship UC Berkeley and Univ. of Bonn |
| 1974 | Doctorate in Economics at Univ. of Bonn |
| 1971-1981 | Research Assistant at Univ. of Bonn |
| 1971 | Diplom in Mathematics at Univ. of Bonn |
| Mathematical Economics |
| Game Theory (Cooperative Games, Market Games, Mechanisms) |
| General Equilibrium Theory (Large Economies, Demand Analysis) |
| Decision Theory |
| Social Choice and Institutional Design |
| Core-Equivalence for the Nash Bargaining Solution. Economic Theory, 25, pp. 255-263, 2005 |
| Implementation of the Nash Solution based on its Walrasian Characterization. Economic Theory, 16, pp. 277-294, 2000 |
| Nonconvergence of Mas-Colell's and Zhou's Bargaining Sets. Econometrica, 65, pp. 1227-1239, 1997 (with R. Anderson and L. Zhou) |
| On the Uniqueness of Individual Demand at almost every Price System. Journal of Economic Theory, 33, pp. 397 - 399, 1984 |