Tamsyn Parker's article at The New Zealand Herald is interesting: it asks us to imagine a world in which a quarter of the workforce are over 55, and 10% are over 65. This is remarkably both difficult and easy. The hard part is that assumptions, long held, are difficult to change. If you grew up thinking of 65 as retirement age, and seeing all these young people around you then when you're older and you see lots of people staying in the workforce you may be forgiven for wondering what went wrong...
...but actually, a lot went right:
Sixty five years ago life expectancy at birth was more than ten years shorter. In 1840 it was usual for most people to be dead by their middle forties, and a cause for celebration if you were still alive at fifty. So, to give our thought exercise a different twist, imagine a world in which half the population are aged more than 82, and most of them are working! That's effectively what has happened over the last 170+ years. With luck, so long as we don't incinerate the planet through war or negligence, it may keep happening. Plus this:
People will still want life insurance.