But the arable land and living space thus created would be the most expensive land ever to have existed, by two orders of magnitude. The Dutch project of reclaiming land from the North Sea would have nothing on this. Every gram of steel and glass, every grain of sand and pinch of clay for the farmland inside would be brought up from Earth, at literally astronomical expense.

I’d love to leave the dying society of Ameri-Kwa behind and live in an O’Neill sky-city with a harem of fertile high-IQ wives. Wouldn’t you? It’s never going to happen, though. Ever. It’s a pipe dream.

Until then, not economical.

No, no they’re not. They’re independent cities. Absent the US or a replacement protecting power they fall.
In Hong Kong’s case they have China, and China has them.

Finally.

May also include:

Yes, that’s precisely our problem (yes, I’m from Sweden). Also, no real upper class or elite, only a very rich middle class. Our entire countries are almost exclusively middle-class.