Debreu, Gerard (1921- )

French-born US economist. He developed mathematical economic models with US economist Kenneth Arrow, and in 1954 they published an epoch-making paper in which they provided a definitive mathematical proof of the existence of general equilibrium, using game theory and the Brouwer-Kakutani fixed-point theorem in topology. He was awarded the Nobel Prize for Economics in 1983.

Debreu was born in Calais, France. He studied mathematics at the prestigious Ecole Normale Supérieure, graduating in 1945. After service with the French occupational forces in Germany, he took up graduate studies at the University of Paris under French economist Maurice Allais which sparked off his life long interest in general equilibrium theory. He was soon identified as a member of the irreverent ‘Bourbaki’ group, a set of young French mathematicians dedicated to the reconstruction of the axiomatic foundations of mathematics. In 1948 he went to the USA on a Rockefeller Foundation Fellowship, and in 1950 he joined the Cowles Commission at the University of Chicago. Debreu left Yale University in 1960. In 2001 he was professor of economics and mathematics at the University of California, Berkeley.

He was president of the Econometric Society (1969-71), a fellow since 1970 of the American Association for the Advancement of Science, a fellow of the American Economic Association since 1982, and its president in 1990. He became Chevalier of the French Legion of Honour in 1976 and Commander de L'Ordre Nationale du Mérite in 1984.