Everyone knows that Germany is aging fast. What most people don't seem to realize is that working-age population is still stable at the moment, but will start declining rapidly within a few years. So the impact on the economy will only start to hit in coming years.
According to the official population forecast (as published by Destatis), the population segment aged 20-65 will change as follows:
2005-2010: -0.1 %
2010-2020: -4.1 %
2020-2030: -11.6 %
This projection assumes 100,000 net inwards migration per year from 2010 onwards. If no net inwards migration takes place (Germany appears to have had no migration surplus in 2008, and only 40,000 in 2007), the numbers are worse:
2010-2020: -6 %
2020-2030: -14 %
It will be rather hard for Germany to achieve any GDP growth at all after 2020, when working-age population drops 1.4 % per year (and presumably by that time, worldwide resource constraints will also be felt much more acutely, making growth even harder).
(The projection assumes fertility of 1.4 kids per woman, roughly in line with what is currently being observed. But even if fertility goes up a bit in the near future, those extra kids won't hit working-age until after 2030)
(For an update of latest fertility trends, click here.)
(For a comparison with other low-fertility countries, click here.)