From the start of the 1960s, the working population grew with the arrival of the «baby-boom» generations and the increasing economic activity of women. Until the start of the 1970s, the creation of new jobs absorbed these additional workers. Then, as studies rapidly became longer and unemployment rose, the retirement age was lowered; working life was thus concentrated during middle age until the middle of the 1990s. Then, with the problem of financing pensions and the predicted fall in the working population, keeping the increasing numbers of «seniors» in employment became the objective. After 2010, the working population will decline. Yet seniors could continue to work in order to increase pension contributions. The fall in the working population will then occur later.