Gerard Debreu, 83, a former University of California at Berkeley economist who won a Nobel Prize for breakthroughs in the study of supply and demand, died Dec. 31 in Paris. No cause of death was reported.
Dr. Debreu taught at Berkeley for more than 30 years. He won the 1983 Nobel Prize in economic sciences for his theoretical work on how prices operate to balance supply and demand.
"He really was the most important contributor to the development of formal math models within economics," said Berkeley professor Robert Anderson in a statement from the university.
Born in the northern French coastal city of Calais, Dr. Debreu stopped his mathematics studies to enlist in the French army after U.S. forces swarmed into France in the D-Day invasion on June 6, 1944, the university said.
He resumed his studies after the war, increasingly focusing on economics, and later became a U.S. citizen. Dr. Debreu also held posts at the University of Chicago, Yale University and Stanford University.
He was broadly known in economics circles for his classic monograph, "Theory of Value: An Axiomatic Analysis of Economic Equilibrium" (1959), which emphasized rigorous mathematics in economic explanations.
Contemporary authors noted that computer models based on his work have been used by the World Bank and other institutions for analyzing trends in national economies and world markets.
His marriage to Francoise Debreu ended in divorce.
Survivors include two daughters; five grandchildren; and four great-grandchildren.