The fundamental issue with declining populations - fundamental as in regardless of the economic system of the country - is decreasing standard of living.
The very simple metric is productivity-adjusted hours worked per person. This invariably falls in cases where overall population is declining, because populations age as they decline, and older people work less (retirement) than younger ones.
As this metric falls, the country’s economy basically just produces less stuff per-person than it did in the past. This makes everyone effectively poorer.
In extreme cases, there can also be issues with availability of services. E.g. healthcare: Each doctor/nurse/caregiver can only effectively attend to so many patients and this number is difficult to increase with technology.
Standard of living is supported by those who can produce versus those who cannot. As population declines the demographics skew to mostly be older non-working people. There is a certain point where the percentage of people working versus not working is too small, then the economy can no longer produce enough for everyone’s current standard of living. It can range from relatively minor case of not being able to get all the variety of food, or it can be major where people starve because not enough food can be produced. Or medicine, or care, or electricity, or oil, or plastic, or TV shows, etc.
Given enough time a new equilibrium and standard of living comparable to the old one will likely result, but getting to that new standard of living can mean people died.
Would it have to be extreme where people are straving? A nation already wealthy has a lot of infrastructure which just needs to be maintained or adapted?
The fundamental issue with declining populations - fundamental as in regardless of the economic system of the country - is decreasing standard of living.
The very simple metric is productivity-adjusted hours worked per person. This invariably falls in cases where overall population is declining, because populations age as they decline, and older people work less (retirement) than younger ones.
As this metric falls, the country’s economy basically just produces less stuff per-person than it did in the past. This makes everyone effectively poorer.
In extreme cases, there can also be issues with availability of services. E.g. healthcare: Each doctor/nurse/caregiver can only effectively attend to so many patients and this number is difficult to increase with technology.
How does producing less stuff make people poorer? Less people need less stuff, and there’s more unoccupied houses?
I think the term is demographic inversion
Standard of living is supported by those who can produce versus those who cannot. As population declines the demographics skew to mostly be older non-working people. There is a certain point where the percentage of people working versus not working is too small, then the economy can no longer produce enough for everyone’s current standard of living. It can range from relatively minor case of not being able to get all the variety of food, or it can be major where people starve because not enough food can be produced. Or medicine, or care, or electricity, or oil, or plastic, or TV shows, etc.
Given enough time a new equilibrium and standard of living comparable to the old one will likely result, but getting to that new standard of living can mean people died.
Would it have to be extreme where people are straving? A nation already wealthy has a lot of infrastructure which just needs to be maintained or adapted?