In economics, the most affected foam definition is given by studying the Kindleberger, which is known for the study of the financial crisis, is given in the "New Palgraph Economics":
The word "foam state", one thing to say, is one or a series of assets to raise the price in a continuous process, and the price rise begins makes people still have to rise, so they attract new buyers. - These people generally just want to take profits through trading, and the ability to use and produce profitability for these assets itself is not interested. As the price increase is often the expected reversal, then it is the risk of prices, and finally ended by the financial crisis. Typically, "boom" time is more mild than the bubble state, price, production and profit, and will then have a crisis in the form of plunge (or panic), or gradually retreat with prosperity. Not a crisis.
Jindelberg has a comparative image of the definition of the bubble, but is more difficult to operate in theoretical research. Modern economics research usually defines foam as the sustainable deviation of asset prices on its basic value. Such definitions simplify the judgment of the bubble, there is two points to do, one is to determine the basic value of the asset, and the second is to see the deviation of asset prices is sustained or disappeared in a short period of time.
Xu Xiaonian: Land myth sells a Shanghai to change most of the United States
