Four essays on the effects of an increase in the retirement age on employment.

Summary Our thesis analyzes the impact of longer working hours on employment through four original contributions. First, using US HRS data, we show that an individual who finds that his employer adopts discriminatory practices towards older employees may revise downwards his or her retirement age. Moreover, an employer may grant bonuses to its older workers to force them to leave. Inspired by the French reforms of 2003 and 2008, we consider a tax on the amount of early retirement bonuses paid by the employer. Through a matching model with endogenous job destruction, we show that in the case of a high tax on these bonuses, an increase in the retirement age encourages firms to part with their senior employees. In a second part of the thesis, we examine the effect of a longer working life on youth employment. By considering an imperfect substitution between young and older workers on the labor market, we show theoretically and empirically through an aggregate firm approach, that a decrease in the retirement of older workers can reduce the hiring of young workers. Moreover, youth employment and senior employment are linked via intergenerational transfers. Thus, using a nested-generation model, we show that the labor supply of young people increases with the amount of time their senior parents devote to caring for their grandchildren, but that longer working lives have an ambiguous effect on the amount of this transfer.