My English is not good, so I'm using as least words as I can to explain.
Many analysts and authors put lines on this topic, and I'm not repeating what they already said. I'm going to tell you something that are not reported on popular English media yet.
1. The bubble not only happen in big cities, situation of county towns is much worse. For example, 3 years ago, a county in south Henan province average home price is less than 900 CNY / sqm. Now it has climbed to over 3000 CNY. Local people are willing to tell you their great invest stories.
No joking, the county is one of the poorest county in that province. Does the county have any industry or other incoming source? Absolutely NO. people born there were forced to travel long to southern cities to earn a monthly salary of 1500CNY (optimistic average)
This home price miracle is happening all over the country. Labor forces rush in to big cities to make money, making the home price there went high. It must be aliens who are rushing to the poor county, where there are a lot of room to park their UFO.
2. Ghost towns also exist in big cities. I live in one of the richest cities for 20+ years, so I can tell that. The area with the highest home prices, is also with a highest apartment density (because of new building technique). And the interesting point is, these areas have the least density of human. The buildings with 30+ layers have very few apartments with lights on.
An irony joke says that the rich don't turn on lights so as to save money. Further more, among a few tens of these high rise, you can hardly find stores, and no restaurants, and no where to find an ATM. The reason is simple, too few people live there. They won't be profitable in such wealthy area.
3. More and more Chinese people become bearish about China's coming few years. Obviously I'm one of them. And I can tell that bearish opinions are most welcomed in better educated younger people. Because we live here, we can feel the irrational enthusiasm.
I was bearish about the US too, in longer term. But at the mean time, I think our situation is much more dangerous. I know many smarts out there know the situation very well and awaiting the black swan coming out.
Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.