He coined the expression Trente Glorieuses ("the glorious thirty [years]") to describe the period of prosperity that France experienced from the end of World War II until the 1973 oil crisis.

Instead, he pursued studies at École Libre des Sciences Politiques where his professors included Charles Rist and Jean Romieu [fr].

During World War II, Fourastié kept working for the state under Vichy France, while keeping distance from direct collaboration with Germany's Nazi regime.

[4] In January 1941, he started giving a course on insurance at the Conservatoire National des Arts et Métiers (CNAM), replacing his ministry colleague Maxime Malinski who was Jewish and thus had been victim of the 1940 Vichy anti-Jewish legislation.

[3] Fourastié then taught at the newly created École nationale d'administration and played an enhanced role in the renewed Plan Comptable committee chaired from 1946 by Robert Lacoste.

He became professor (Directeur d'études) at the VIth section of the École Pratique des Hautes Études (later EHESS) [5] in 1951, and from 1960 he held the chair of Economics and Industrial Statistics at CNAM.