I want to repost a graph from destatis (German statistics institute) I have posted before. There are a lot of changes due to historical events and fashionable live styles (Baby-boom, -bust, war, migration), which have effects.


It shows in blue the number of people older than 65 years per 100 people between 20 and 65. In green the number of people below 20, as the sum of these people is expected to be those who can't earn their own income. For the modelling it is assumed, that net immigration will be around the value of the last ten years (so slightly higher than currently), constant fertility and some reasonable assumption about life expectancy.

Der Amerikaner ist die Orchidee unter den Menschen
Volker Pispers