By saving you are in fact betting on your ability to threaten young people with material deprivation to force them to take care of you.

You could make a different bet, e.g. invest into whatever infrastructure they'll need to take care of aging population. But your savings fund likely invests in luxuries for aging big spenders, so...

I am rather curious how this plays out long-term, since there is no investment instrument for "please build train / underground closer to my house".

The whole comment is a bit non-sensical, so I am not sure how to respond. If you are not from the US, you should know that social security is not an option, it is a mandatory program. Things like 401k plans are tax incentivized, and as we know, humans love incentives. Most 401k plans are in index funds, which track a large number of companies, so I am not sure what "luxuries for aging big spenders" means but it sounds like you have it figured out.

> Most 401k plans are in index funds, which track a large number of companies

Who will work in these companies? Who will buy their products and fuel their revenues?

People of all shapes, sizes, and economic levels…not sure what your point is?

That's the respond to your statement above:

> How many children my neighbor has impacts my social security payments or other retirement disbursements in no tangible way.

All the retirement savings you have, whether state-managed or private-managed, are just some coupons for your share in the economy of the future. If the economy of the future shrinks your coupons will be worthless.

The number of kids you and your neighbor have not only have an impact on your retirement, these kids are your retirement.

Fewer people means fewer customers.

Holding company shares does nothing. Those shares are used as a medium of exchange with people actually doing some productive investment elsewhere.

The investment happens when somebody sells you the shares in exchange for fiat used to pay off the workers. Who do you buy your shares from? That's where you invest.

As for the first part, holding fiat or assets convertible to fiat when fiat has been issued with interest and must be eventually repaid under threat of confiscation of assets. :shrug: It's basically a game of chicken.