Our aim is to observe the evolution of this instability from several perspectives: career mobility from employment to unemployment, wage mobility and socio-professional mobility. Two approaches will be jointly used as we will perform a secondary analysis of many Insee studies, among which the Permanent demographic sample (EDP panel) and the Annual declaration of social data (DADS) (but also the vocational training and qualification (“FQP”) survey, as well as the labor surveys). Most studies on professional mobility analyze this theme from a transversal perspective (from one date to another date). We will also use this perspective (from the end of the 1960s up to nowadays) but with a complementary longitudinal and/or biographic perspective which will set the career as an analysis unit. It will be centered on three sociologically relevant cohorts (generations born between 1944 and 1948, 1958 to 1962 and 1974 to 1978). This perspective will enable us to distinguish period effects from age effects and from cohort effects.