Debreu was orphaned at an early age, as his father committed suicide and his mother died of natural causes.

[2] Prior to the start of World War II, he received his baccalauréat and went to Ambert to begin preparing for the entrance examination of a grande école.

Later on, he moved from Ambert to Grenoble to complete his preparation, both places being in Vichy France during World War II.

In 1948, Debreu went to the United States 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 Associate and joined the Cowles Commission at the University of Chicago in the summer of 1950.

The main idea of his argument is to show that there exists a price system for which the aggregate excess demand correspondence vanishes.

Here, he introduced the notion of a contingent commodity, which is a promise to deliver a good should a certain state of nature be realized.

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