Gerard Debreu

Gerard Debreu was a French-born American economist and mathematician who made significant contributions to the field of general equilibrium theory and mathematical economics. He was awarded the Nobel Memorial Prize in Economic Sciences in 1983 for his rigorous reformulation of the theory of general equilibrium and his incorporation of new analytical methods into economic theory. Debreu was born in Calais, France, on July 4, 1921. His father was a lace manufacturer and his mother was a homemaker. He was orphaned at an early age, as his father committed suicide and his mother died of natural causes. He attended the College of the City of Calais until 1939, when he moved to Ambert to prepare for the entrance examination of a grande école. He later transferred to Grenoble to complete his preparation, both places being in Vichy France during World War II. In 1941, he was admitted to the École Normale Supérieure in Paris, where he studied mathematics under Henri Cartan and the Bourbaki group. He was also influenced by the general equilibrium theory of Léon Walras, a pioneer of mathematical economics. In 1944, he postponed his final examinations to enlist in the French army after the Normandy landings. He was sent to officer school in Cherchell, Algeria, and then served in the occupying French forces in Germany until July 1945. He then returned to Paris and passed the Agrégation de Mathématiques exams at the end of 1945 and the beginning of 1946. From 1946 to 1948, he worked as an assistant in the Centre National de la Recherche Scientifique, where he made the transition from mathematics to economics. In 1948, he received a Rockefeller Fellowship that allowed him to visit several American universities, as well as those in Uppsala and Oslo. He met several prominent economists, such as Kenneth Arrow, Paul Samuelson, Tjalling Koopmans, and John von Neumann. In 1950, he joined the Cowles Commission for Research in Economics at the University of Chicago, where he collaborated with Arrow on the existence and uniqueness of general equilibrium. He moved with the commission to Yale University in 1955. He received his doctorate in economics from the University of Paris in 1956. In 1960, he became a professor of economics at the University of California, Berkeley, where he taught until 1991. He also held a joint appointment as a professor of mathematics from 1975. He became a U.S. citizen in 1975. He published his classic monograph, Theory of Value: An Axiomatic Analysis of Economic Equilibrium, in 1959. In this book, he provided a rigorous mathematical foundation for the theory of general equilibrium, using tools such as convex sets, topological spaces, fixed-point theorems, and integrable correspondences. He also developed methods to analyze the stability, uniqueness, and optimality of equilibrium states. Debreu received numerous honors and awards for his contributions to economics. He was made an officer of the French Legion of Honour in 1976 and a commander of the French National Order of Merit in 1984. He was elected a member of the National Academy of Sciences in 1977 and a fellow of the Econometric Society in 1978. He served as president of the Econometric Society in 1970 and president of the American Economic Association in 1990. He received honorary degrees from several universities around the world. He won the Nobel Memorial Prize in Economic Sciences in 1983. Debreu married Françoise Bled in 1946 and they had two daughters, Chantal and Florence. He died in Paris at the age of 83 of natural causes on December 31, 2004. He was buried at the Père Lachaise Cemetery in Paris. He is widely regarded as one of the greatest economists and mathematicians of the twentieth century. His work has influenced generations of economists and has advanced the understanding of economic theory and its applications.