The long-term demographic projections have progressively raised concerns about the consequences of ageing population. To better understand those changes and measure their size,
projections of social expenditure have been built and progressively refined. Confronted with a large budgetary cost of ageing in the long run, the Government’s alternative is: solve the problem
when it comes up or try to anticipate the negative results and prevent them. Three ways are to be considered that are not mutually incompatible: reforming the social system in order to reduce the cost for the present and future generations, increasing the tax or contribution receipts by pushing up employment rates and the trend growth of GDP and saving now in the public sector to cover the increase of the future expenditure. The paper shows that, since the end of the nineties, a broad movement of reforms has taken place in the EU which involves this three-pronged strategy.