> The opposed view is that decadence is a good thing: not making things is a natural consequence of being so wealthy and powerful that you don't need to make things. That things just get made, whether by machines or by less wealthy nations, and you just pay for them.

Except that's a fantasy. Eventually those "less wealthy nations" will realize the little green pieces of paper have no real value, that they actually control the real wealth, and then they should demand payment in something that's actually valuable, which the "wealthy" nation can no longer provide.

> I feel fairly confident that the long-term (within the next century or two, say) trajectory for human population is much more likely one of approaching an asymptote, rather than one of overshooting what is sustainable and then seeing billions of deaths.

It sounds like you're describing some kind of sudden Malthusian collapse due to mass starvation or something, which is not what I was talking about. I'm talking about a much slower process, where sub-replacement reproduction fails to replace, and you eventually get manpower shortages and too few people to care for the elderly without starving other parts of the economy.