The Determinacy of Equilibria 25 Years Later

Abstract

The paper by G. Debreu, ‘Economies with a Finite Set of Equilibria’, appeared in Econometrica in 1970. As is commonly known, the paper has had since then a great impact on the style and the substance of economic theorizing. If I had been more energetic I would have verified this impact in the Index of Citations. Yet, whatever the latter says, it is bound to be a considerable underestimate of the impact. Often, the sign of the success of a paper is its being referred to only implicitly, without authors even being aware of the fact. In our case, for example, any user of the term ‘generic’ is indebted to Debreu’s paper. At any rate, the research directly inspired by the paper is enormous. By now it includes, at least, two full-length systematic books (Balasko, 1988, and Mas-Colell, 1985).

This is a lecture that I delivered at the University of Bonn on 4 July 1991 on the occasion of the seventieth anniversary of G. Debreu (the celebration was organized by W. Hildenbrand). Its content has a substantial overlap with the comments I delivered in Moscow at the Congress of the IAE.