Gerard Debreu was a naturalized US citizen from France

Gerard Debreu (July 4, 1921 – December 31, 2004) was a French economist and mathematician (In July 1975, he became a naturalized citizen of the United States). He won the 1983 Nobel Memorial Prize in Economics. Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... July 4 is the 185th day of the year (186th in leap years) in the Gregorian Calendar, with 180 days remaining. ... 1921 (MCMXXI) was a common year starting on Saturday (see link for calendar). ... December 31 is the 365th day of the year (366th in leap years) in the Gregorian Calendar. ... 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... 1975 (MCMLXXV) was a common year starting on Wednesday. ... Naturalization is the process whereby a person becomes a national of a nation, or a citizen of a country, other than the one of his birth. ... 1983 (MCMLXXXIII) was a common year starting on Saturday of the Gregorian calendar. ... The Bank of Sweden Prize in Economic Sciences (Swe. ...

He was born in Calais. His father was the business partner of his maternal grandfather in lace manufacturing, a traditional industry in Calais. Location within France The Burghers of Calais, by Rodin, with Calais Hotel de Ville behind J.M.W. Turner: Calais Pier Calais (Dutch: ) is a town in northern France, located at 50°57N 1°52E. It is in the département of Pas-de-Calais, of which it is a...

Just prior to the start of World War II he received his baccalauréat, and went to Ambert to begin preparing for the exam for entering a grande école. Later on he moved from Ambert to Grenoble to complete his preparation, both being in the so-called "Free Zone" during World War II. This article is becoming very long. ... Lycée Louis-le-Grand (on the right) in Paris is one of Frances most famous lycées, with a rate of success to baccalauréat usually above 99%. The baccalauréat (IPA: ), often known in France familiarly as the bac, is an academic degree which French students sit... Ambert is a commune of France, loctated in the former province of Auvergne. ... The grandes écoles (French for great schools) of France are higher education establishments outside of the mainstream framework of the public universities. ... Ambert is a commune of France, loctated in the former province of Auvergne. ... , Grenoble (Occitan: Grasanòbol) is a city and commune in south-east France, situated at the foot of the Alps, at the confluence of the Drac into the Isère River. ... This article is becoming very long. ...

In 1941 he was admitted to the École Normale Supérieure in Paris, along with Marcel Boiteux. He was influenced by Henri Cartan and the Bourbaki writers. When he was about to take the final examinations in 1944, D-Day arrived and he instead enlisted in the French army. He was transferred for training to Algeria and then served in French occupational forces in Germany until July 1945. This article is about the year. ... The quadrangle at the main ENS building on rue dUlm is known as the Cour aux Ernests – the Ernests being the goldfish in the pond. ... Part of the Paris area skyline with from left to right: Montparnasse Tower, Eiffel Tower, and La Défense. ... Henri Cartan (born July 8, 1904) is a son of Élie Cartan, and is, as his father was, a distinguished and influential French mathematician. ... Nicolas Bourbaki is the pseudonym under which a group of mainly French 20th-century mathematicians wrote a series of books of exposition of modern advanced mathematics, beginning in 1935. ... 1944 (MCMXLIV) was a leap year starting on Saturday (the link is to a full 1944 calendar). ... Land on Normandy In military parlance, D-Day is a term often used to denote the day on which a combat attack or operation is to be initiated. ...

Debreu passed the Agrégation de Mathématiques exams at the end of 1945 and the beginning of 1946. By this time he had become interested in economics, particularly the general equilibrium theory of Leon Walras. From 1946 to 1948, he was an assistant in the Centre National de la Recherche Scientifique. During these two and a half years he made the transition from mathematics to economics. Marie-Ésprit-Léon Walras (December 16, 1834 in Évreux, France - January 5, 1910 in Clarens, near Montreux, Switzerland) was a French economist, considered by Joseph Schumpeter as the greatest of all economists. He was a mathematical economist associated with the creation of the general equilibrium theory. ... The Centre national de la recherche scientifique (CNRS) is the largest and most prominent public research organization in France. ...

In 1948, Debreu came to the USA on a Rockefeller Fellowship which allowed him to visit several American universities, as well as those in Uppsala and Oslo in 1949-50. Debreu began working as a Research Association and joined the Cowles Commission at the University of Chicago in the summer of 1950. Uppsala (older spelling Upsala) is a Swedish City in central Sweden, located about 70 km north of Stockholm. ... County Oslo NO-03 District Viken Municipality NO-0301 Administrative centre Oslo Mayor (2004) Per Ditlev-Simonsen (H) Official language form Neutral Area  - Total  - Land  - Percentage Ranked 224 454 km² {{{arealand}}} km² 0. ... The University of Chicago is a private university located principally in the Hyde Park neighborhood of Chicago, Illinois. ...

There he remained for five years, returning to Paris periodically. In 1954 he published a breakthrough paper titled Existence of an Equilibrium for a Competitive Economy (together with Kenneth Arrow), in which they provided a definitive mathematical proof of the existence of general equilibrium, using topological rather than calculus methods. Kenneth Arrow Kenneth Joseph Arrow (born August 23, 1921) is an American economist, winner of the Bank of Sweden Prize in Economic Sciences in 1972. ...

In 1955 he moved to Yale University. In 1959 he published his classical monograph, Theory of Value: An Axiomatic Analysis of Economic Equilibrium, (Cowles Foundation Monographs Series), which is perhaps the most important work in mathematical economics. He also studied several problems in the theory of cardinal utility, the additive decomposition of a utility function defined on a Cartesian product of sets. Yale redirects here. ...

In this monograph, Debreu sets up an axiomatic foundation for competitive markets. He establishes the existence of equilibrium using a novel approach. The main idea is to show that there exists a price system for which the aggregate excess demand correspondence vanishes. He does so by proving a fixed point like theorem based on Kakutani's fixed-point theorem. In Chapter 7 of the book Debreu introduces uncertainty and shows how it can be incorporated into the deterministic model. Here he introduces the notion of a contingent commodity, which is a promise to deliver a good should a state of nature realize. This notion is very used in financial economics as Arrow Debreu security. The Arrow-Debreu-McKenzie model (ADM model) is the central model in the General (Economic) Equilibrium Theory and often used as a general reference for other microeconomic models. ...

In 1960-61, he worked at the Center for Advanced Study in the Behavioral Sciences at Stanford and devoted mostly to the complex proof that appeared in 1962 of a general theorem on the existence of an economic equilibrium.

In January of 1962, he started worked at the University of California, Berkeley where he held the title University Professor and Class of 1958 Professor of Economics and Mathematics Emeritus. During his leaves in late sixties and seventies he visited universities in Leiden, Cambridge, Bonn, and Paris. The University of California, Berkeley (also known as UC Berkeley, Berkeley, Cal, and by other names, see below) is the oldest and flagship campus of the ten-campus University of California system. ... Leyden redirects here. ... Shown within Cambridgeshire Geography Status City (1951) Region East of England Admin. ... Bonn is a city in Germany (19th largest), in the Federal State of North Rhine-Westphalia, located about 20 kilometres south of Cologne on the river Rhine in the north of the Siebengebirge. ... Part of the Paris area skyline with from left to right: Montparnasse Tower, Eiffel Tower, and La Défense. ...

His later studies centred mainly on the theory of differentiable economies where he showed that in general aggregate excess demand functions vanish at a finite number of points. Basically, showing that economies have a finite number of price equilibria.

In 1976 he received the French Legion of Honor. He was awarded the 1983 Bank of Sweden Prize in Economic Sciences in Memory of Alfred Nobel for having incorporated new analytical methods into economic theory and for his rigorous reformulation of general equilibrium theory. Medal for the officer class, decorated with a rosette Napoleon wearing the Grand Cross The President of France is the Grand Master of the Legion. ...

In 1990, he served as President of the American Economic Association.

Debreu married Françoise Bled in 1946 and had two daughters, Chantal and Florence, born in 1946 and 1950 respectively.

Debreu died in Paris at age 83 of natural causes on New Year's Eve, 2004 and was interred in the Père Lachaise Cemetery. New Years Eve is a celebration held the day before New Years Day, on December 31, the final day of the Gregorian year. ... Looking down the hill at the Père-Lachaise cemetery The cimetière du Père-Lachaise (pronounced pierre la-sh-ez) is the largest cemetery in the city of Paris (there are larger cemeteries in Paris suburbs). ...

External links

• The Bank of Sweden Prize in Economic Sciences in Memory of Alfred Nobel 1983
• Existence of an Equilibrium for a Competitive Economy
• Obituary for Debreu