Gerard Debreu

Gérard Debreu (July 4, 1921 – December 31, 2004) was a French economist and mathematician, who also came to have United States citizenship. Best known as a professor of economics at the University of California, Berkeley, where he began work in 1962, he won the 1983 Nobel Memorial Prize in Economics.
== Tossup Questions ==
# This thinker introduced a coefficient of resource utilization to evaluate the deadweight loss associated with Pareto nonoptimality. Expanding on a result by Sonnenschein, this person proved with Mantel that Walrasian identity and continuity characterize the aggregate excess demand function in a result that nevertheless shows that individual rationality assumptions do not imply uniqueness or stability of general competitive equilibria. With an American, this person proved that demand independence, perfect competition, and convex preferences guarantee the existence of at least one set of prices such that aggregate supply and demand are (*) equal for all commodities. This person showed that any Walrasian equilibrium is Pareto-efficient, thus proving the fundamental theorem of welfare economics, with Kenneth Arrow. For 10 points, name this winner of the 1983 Nobel for his reformulation of general equilibrium theory, a French-born economist.