One important point not mentioned: Japan were alone when the country's economy collapsed in late 80's. Today's China is surrounded with relatively strong peripheral economies (Taiwan, Korea, etc.) The support is there. Also, do not discount black-market economy. It's difficult to keep track of economic progress in a cash-based economy. The strength of China's domestic economy is often discounted by foreigners because of economic activities unaccounted for. The real worry is the aging population and the lack of social welfare.