Vieillissement de la population et prise de risque sur les marches financiers

Using a long time series of the stock market return as well as of the demographic structure of the population, we show several robust economic relationships between demographic changes and the equity premium. Seniors' fraction in the population is a strong predictor of the market return. A rise in this fraction predicts an increase in stock prices and thus a reduction of the risk premium. This is reminiscent of a decrease in the aggregate risk aversion in the economy. Moreover, the ratio of the man population to the woman population by age group is also shown to have some predictive ability.