Heh. Dollars are easily convertible in virtually any amount. They're the world's reserve currency, remember? Dollars held by the Chinese are already in circulation, anyway. They can also hedge in the synthetic derivatives market, as well. It's not in their interests to either cause a dollar value decline or to revalue the yuan upward, anyway, and they've done what they can to provide stability. Funding US debt is part of that. If too many dollars don't come home, one way or another, their value will decline.
The Chinese economy is currently incapable of absorbing all the goods they could buy with their foreign reserves, so they're trying to change that, boost domestic consumption in a variety of ways. And the "ghost cities" are part of that- housing ready for the ongoing migration from the countryside that's occurring at the rate of 20-30M people / year. They won't be moving into shanty towns. Our own "ghost suburbs" won't be filled any time rsn, other than with immigrants, because our urban migration was over long ago. The notion that their housing surplus is worse than our own is absurd, because theirs is paid for, and because of the Chinese urban migration already mentioned.
All their fault, the Chinese, that is? Hardly. American capitalists have benefited every bit as much if not more. Our largest corporations. Our wealthiest citizens. It's not like the Chinese forced them to invest in China, or that the American public wasn't led into letting it be that way, at all. International capitalism and all that comes with it, remember? Or was there some part our leaders forgot to mention?
Of course they've bootstrapped themselves into the 21st century- it wasn't an accident, but rather the result of having leadership with vision & savvy. The notion that they'll suddenly derail & fly off the tracks of history is delusional wishful thinking, particularly considering their performance over the last 40 years.
So, uhh, anybody who wants to disparage the Chinese, engage in the usual raving and chest thumping over the internet using chinese made hardware, sitting in a chinese made chair at what's probably a chinese made desk, be my guest, fools.