what does it mean to "pay for" the continued care of the old.
Unless we have such a population implosion that we can no longer produce food or run our factories, then we don't need to "pay for" anything. We can simply decide to distribute the resources necessary for the care of the old.
The real cost of everything is the labor required to produce it, not the dollar value it receives in a market place. I don't think anyone is talking about a complete collapse in the labor pool.
Yes, but e.g. Japan faces a big problem where the labor pool will be a small part of the population, with a big noticeable slice involved in elder care. If current plans to automate large amounts of this work (and I worry that automating it could be horribly dystopian) do not succeed it will be a large problem. (Not to mention other types of resources that those not in the labor force consume besides direct care).
Pensions, social security, etc. The point is that the "active economy" will shrink beneath what was expected for those systems to function for the number of elderly they will end up having.
Unless we have such a population implosion that we can no longer produce food or run our factories, then we don't need to "pay for" anything. We can simply decide to distribute the resources necessary for the care of the old.
The real cost of everything is the labor required to produce it, not the dollar value it receives in a market place. I don't think anyone is talking about a complete collapse in the labor pool.