While I cannot remember or reference the source........

My understanding is, that the main (or a large % of) financial backing for these ghost cities is your ordinary Chinese citizen. They do not trust many of the traditional investment strategies/ or banks like we do here, and with shady sales people giving them the whole speil of huge returns by buying in on a new tower or apartment complex. All those billions of people need to live somewhere right? So they throw a huge chunk of their savings into these shady investment schemes.

I'll try to remember where I saw this discussed.....