Well... no bubble is the same, otherwise we'd be able to spot them and avoid them every time, right? If there is a common factor in housing bubbles, it's the extent to which housing moves away from its primary purpose (ie. a roof over a family's heads). In China housing has become a massive source of income for local governments, income for developers, and an investment vehicle for rich people. It has all the signs of being a classic bubble and the only question is how/if the government can deflate it. Also don't forget that a lot of people pay cash because they can't get a mortgage or don't trust the banks, but they still borrow money from friends, family, lending circles or other informal sources - there is often still a wobbly chain of debt behind each purchase.