Article dans une revue: It is argued that the tax on continued activity should be removed by implementing actuariallyfair schemes. However, these schemes cannot fund the expected Social Security deficit. This paper proposes to give individuals a fraction of the actuarially-fair incentives in the case of postponed retirement. Social Security faces a trade-off between giving enough incentives to make individualselay retirement and giving little increase in pensions in order to help finance its expected deficit. This trade-off is captured by a Laffer curve. Finally, when the Social Security system aims to maximize welfare, the optimal tax on postponed retirement is still strictly positive.