I'm curious to hear what sort of economic models you have in mind that works with a non-growing or declining population
It's not like Japan deteriorated into some extreme poverty because of it, right?
So maybe it's not that bad, "to be in decline" (in population number, or related GDP), as we are meant to believe?
I think it's a little too early to draw conclusions. Japan reached their peak population in about 2010, and the decline since has been mild.
> ...pretty painful.
How will the subjected population notice that you reckon? Prices change, sure, but many of us on earth also live in a lot more luxury than 200 years ago: so we have some fat on our bones.