Seriously, that's the kind of statistics people need to think about a little bit more. We are living longer, and our population is getting older. How is this a bad thing? Or is it that taking care of "improductive" old people (you know, those that run our charities and NGOs, take care of their grand children, and spend their hard earned money to keep the economy humming along...) a bad thing? In the long run, we're all dead. John Maynard Keynes
Where do I collect my ration? The fact is that what we're experiencing right now is a top-down disaster. -Paul Krugman
It would be better to start increasing pension ages to take into account that we're living longer and keep fit people economically active for longer.
Also, one major reason that birth rates are falling is that living in W Europe is so expensive that raising children is becoming an unaffordable activity. Increasingly you need two incomes to keep a roof over your head and many are putting off having children in the hope that they achieve a stable financial state before it's too late.
Cheaper housing would help, but in the UK where employment is largely squeezed into the bottom right hand corner, this is impractical. keep to the Fen Causeway
This is the theory, but it is a limited theory. Children and jobless people are economically inactive too (and you described the former's costs), and retirement age can be changed (as you write too) - but is not worth much if only unemployment numbers rise as a consequence. (Present policy is the opposite -- to hide part of unemployment with early retirement.) The ratio of working people to all economically inactive people whom they support can be the same with rather different age structures. *Lunatic*, n. One whose delusions are out of fashion.
