> Would a shrinkage still cause economic collapse?

Sort of maybe yes.

Even when you save up the cash up front, you live off return on the investments. Of course you can invest globally, but wherever you invest, you rely on there being a young productive workforce to generate said return on investment.

Ultimately, cash is a nice abstraction, but you need someone doing the actual doing - harvest food, run hospitals, fire stations etc. With many old people around, there's many people who need services (especially health) but few to run them.

Where you are better off is you ringfence the saved up cash for investments, ensuring you have more growth to finance the whole party when it comes to it. In principle the state can do it too, but it's often too tempting not to.

In a world with a constantly shrinking population, what investment is expected to grow over time?

- Stocks are a melting ice cube selling to a perennially shrinking consumer base.

- Bonds offer low returns and suffer from credit risk due to the above. Do we really think Japan is good for their 2055 bonds, assuming no inflation or debasement?

- Property also faces challenges with a shrinking population. Rural Korea, Japan, Italy and other places are already full of housing and commercial buildings selling for $30k and they're all overpriced.

The truth is that there is no model of retirement -- not the state model, private investment model, or family model that works in a world where the population is shrinking 50-70% per generation.

Young people will take less financial risks, because if your bet does not pay off and you lose all your money, you starve. Which means less purchase, fewer companies founded, less demand for existing companies, and worse economy.

Even worse, some young people will still take financial risks, their bets do not pay off, and they become the penniless old, who only have their own kids to look after them. These young people are now stacked with debt, having to pay off money they've never even seen. Again, worse economy, and more misery.

In the long term, society is shaped by its people. If enough people decide "I'll take care of myself, and others should do the same," then that's the society you get - one mistake or accident and your life is ruined. There's your personal responsibility, choose wisely.

What portion of the population currently live paycheck to paycheck? That portion will die in the streets.

How do you handle the transition? Either the changes aren’t retroactive and the transitional generations have to fund their own retirement and the grandfathered folks, or they are retroactive and the elderly are either destitute or again supported by people funding their own retirement.

It would be an immense cost on those transitional generations. It seems terrible for the economy. Workers now have to save more of their paychecks, but also need compounding growth on stocks to make retirement feasible.

Lot of starving old people... And probably shoplifting... So lot of them would end up in prison which would be quite expensive at least if those prisons were kept at western standards.

You wouldn't get a collapse, but necessarily a contraction, the pie is getting smaller regardless, having less people to "eat it".

Yes, having a system based solely on positive demography isn't any good. In fact, I would argue that the reverse of this scenario is much worse. No matter what some would like to pretend, ressources are finite on earth and if you have a population big enough that deplete them faster that they can be renewed/recycled it is not good.

In any case I think it's wrong to look at it as a purely economic problem. It seems logical that one should be accountable for one's own retirement.

Previously this was done by having kids, because regardless of the economic situation they could always build on what the parents had and it doesn't take much to support your elder (unless they want a luxurious lifestyle).

Part of the problem is that the old generations (especially the boomers) have re-routed ressource distribution to themselves and you have an overspending on the past at the expense of future building.

The incentive around the providence state and pensions were all wrong in the first place now people are surprised that the results are undesirable (usually the one who advocated for the system).

It's not about money per se, which can be printed etc. It's about missing supply of services and to some extent products.

People in South Sudan feel very financially secure you reckon?

Korean work culture is so awful I'm not sure they could even find enough foreigners willing to work like this long-term. Also the language is really hard to learn.

The only solution IMO would be a culture change. But this is not going to happen while old people hold the reins everywhere.

I think people are talking about immigration, though it's a thorny issue, partly because Korea has been virtually monoethnic for a very long time. But I think Korea will eventually have to open up more: the current population crisis is so dire that I don't think Korea is in a position to choose its medicine.

(I don't think immigration alone will solve the problem, BTW - Korea should obviously fix its horrendous work culture, education, and runaway housing prices.)

I think part of it is, as the youth numbers decline, the culture declines with it. This is addressed in the video, people >18 and <40 are those who keep traditions and culture alive. If you somehow imported a bunch of babies who were raised in Korean families, Korean culture survives, and if you import a bunch of 60+ people, well they're not going to be spreading their culture as much as someone who is 30. But babies and the elderly aren't the ones immigrating all that much, it's the (relatively) young singles and families. If you somehow managed to keep up the current population of SK by importing only young Thai families, within 4 generations SK would be North Thailand. I think is only a small part of why many countries are resistant to immigration, and on the micro-level, it's as simple as asking, do you want more neighbors? Or less? And I think, generalizing greatly, most people would say less.

From personal experience, the east Asian culture is not very immigrant-welcoming. It might change if population continues to shrink, though.

I think for some questions of resource scarcity, it can. Specifically this would apply to housing and material possessions (because war can decrease the population)

When the resources which are scarce are young, able-bodied workers who can caretake for the elderly while tilling the fields, I imagine war would exacerbate the problem.

Well, traditionally this would be the case anyway. In the modern age of warfare where civilians are killed with impunity, I imagine the casualty among non-combatants tracks population demographics more generally. So if there are twice as many people over the age of 60 as there are under 20 (for context, the population of these two groups was roughly equal starting in 2024 in the U.S.[1]), then one could imagine twice as many people in that age group dying. Perhaps more if population groups are required to relocate periodically to avoid bombings (as we've seen in Gaza) where the elderly are less capable of walking distances than the young.

[1]: https://www.populationpyramid.net/united-states-of-america/2...

It could, but then who'd be the ones fighting and dying in the war to make new opportunities for the survivors?

Not really unless it somehow leads to fundamental regime change which can "disrupt" the various conditions described in the video. (Remove from power all the beneficiaries of current policies and replace them with better alternatives. Not easy ...)