The demographic trend of decreasing and eldering population, as it is the case in Germany, induces negative effects on the social security system, on the productivity as well as on the innovation potential of the economy. In particular, a higher fertility would ensure a sustainable demographic growth.This project investigates the ecomonic effects of a decreasing and eldering population, the backgrounds of the differentiated demographic trends in the industrialised countries, the motives of the demographic development in Germany, and the impact of public policy measures as regards fertility.