Les démographes et le temps

This article shows how demographers have dealt with the question of time since WWII. Time, a central dimension of demography, has been both a tool for measuring demographic phenomena and an object of study in itself, and the ways it has been taken into account have considerably developed since the 1950s. The most usual point of view at the time, which was synchronic, was later to be completed by a longitudinal, then biographical and finally multi-faceted approach. At each of these stages, the question of time (individual or collective), as well as of how to measure it and how to evaluate its significance, came under more scrutiny, reminding use how complex an object it is to grasp. After a review of these various stages, the paper examines those demographic studies that have focused on time and social temporalities, particularly through the factors of age, generation or transition markers