60 Minutes did a story on the Chinese Ghost towns and it apepars they have 2 main sources;

• Chinese, who have only been allowed to own property in the last few decades, have never seen housing prices go down, and believe they will forever go up.  So they are investing their life savings into 2nd, 3rd, and 4th homes that no one lives in believing they will sell it for a profit some day.  This has created entire suburbs of empty homes, condos, etc.
• The Chinese Government has built entire cities on the same presumption, mostly on the theory that they need to crate jobs to keep the economy going.

So yes, it's a housing buble that will definitely burst some day when people become shocked that they can no longer sell their home for what they paid for it because there is so much real estate on the market.  Once people stop buying for investment reasons, it all goes to pot there.

Shalom,

Joe