I get how an excess of pensioners (not enough workers) in an economy can be a problem. I get how an excess of unemployed people (people without a job) can be a problem. What I don't get is how both can be a problem at the same time.
I think you're simplifying the relationships too much. First of all, you can't very easily make more qualified workers because you promised too much to too many pensioners. Those pensioners are counting on promises from their too-big-to-fail governments. Meanwhile, the government is funneling an ever-greater percentage of revenue from productive pursuits to pensions. Once you're in the trap, it's not as simple as pen…
That is too simplistic for me. Income for one also is income for somebody else down the line.
All those "economic" considerations I read about - not just on this topic - remind me of my extremely lousy chess play: Never think more than a single step ahead.
But the economy is a circle. All those views are form the PoV of an individual entity - income and expenses, and where it comes from and where it goes "does not matter".
But to look at the economy is completely different! Here you have to look at the entire circle, not at just a single piece of the chain.
For example, giving old people money, directly or indirectly, leads to an increased flow of money through systems of the economy that are utilized by old people. That would be the health sector most of all, not a lot of change in housing or food (they already had a roof to live under before they retired and they won't eat more food than before). Maybe tourism benefits too.
What happens if they get less money? What sector(s) benefit(s), who loses?
The purely financial considerations don't make sense to me on the greater economic level. Is the economy suddenly unable to maintain the housing and produce sufficient food because some numbers in some balance sheets are off? That happened a lot in history. My own grand parents lived with at least five different currencies within their lifetime without moving (Germany). We found that "finance" can easily be reset provided people are willing to do so (that's the important part) - what matters is factories, knowledge, culture, trade, etc.
There certainly are a lot of problems of high pensions (compared to non-pensioners), for example if the old people end up with a larger share of the available housing, which includes not just housing they themselves use but also housing they control (investments) because that funnels even more of the money flow through the economy through the control of (some relatively few) old people. that may no lead to a housing shortage, after all who owns housing does not seem so important as long as there is enough, but a consequence is that young(er) people feel insecure in their outlook and are more reluctant to have a family. Also, the kinds of housing being built is probably different when done purely as an investment.
As for the health sector, I'm not sure how bad it is to have it deal (even more) with old people's problems. After all, aging is everybody's problem at some point and if that leads to progress, be it symptom control or some day even more direct control of aging I don't see why getting more of the economy's money flow to go through that sector would be bad. After all if "cost control" was the overwhelming argument then collective suicide would be the best solution. Since we are alive and like it that way we may as well "waste" our resources on just that.
We have that wonderful tool "money" and "finance", but I think too many people have forgotten that it is a tool and treat it like a natural law and the be-all and end-all. We actually have much greater control - and much more arbitrary control than a lot of people think - over how we use the tool. Unfortunately only severe crisis opens the minds of people enough to wield the power we actually have over our own creation.