The Foundation was established in the autumn of 1942 and worked in both biology and the social sciences. After the liberation of France, it became highly coveted, with republican and communist mandarins fighting to seize control over this reputedly collaborationist institution. After some hesitation, General de Gaulle, then in charge of the provisional government, acted on a suggestion by Robert Debré and established a national demography institute, which took over one of the foundation's offices, along with the few staff members (7%) who worked on population questions.
The Institut national d'etudes démographiques (National Institute for Demographic Studies, or INED) was established by decree no. 45-2499 on 24 October 1945. The decree also stipulated the Institute's mission: "The role of INED is to study demographic problems in all their aspects. To this end, the Institute shall collect the relevant documentation, conduct surveys, carry out experiments and follow experiments conducted abroad, study the material and moral means which may contribute to the quantitative growth of the population and its qualitative development, and ensure the dissemination of demographic knowledge".
General de Gaulle appointed Alfred Sauvy, a statistician and economist, to manage the new Institute. Sauvy had published the first policy measures for increasing the birth rate in 1938 when he was advisor to Paul Reynaud, then minister of finance.