为什么会发生金融危机?或者说为什么金融市场会经常发生危机?

金融市场是资产市场,具有与商品市场不同的特点。在商品市场中,商品价格上涨,驱使供给增加或需求减少,进而驱使商品价格降低,低价会驱使供给减少或需求增加。也就是说,供需趋向于均衡,一只“看不见的手”在支配着经济活动。

而在资产市场,情况恰恰相反:价格上涨会吸引更多的人买入同时供给减少,而资产的价格下跌会导致抛售同时供给增加。资产市场具有内在的不稳定性。

The critical difference between markets for goods and those for assets is how the markets respond to shifting prices, or equivalently shifting demand. In the goods market, higher (lower) prices trigger lower (higher) demand; in the asset market higher (lower) prices trigger higher (lower) demand. One market is a stable equilibrium-seeking system and the other habitually prone to boom-bust cycles, with no equilibrium state.

In goods markets items are purchased for consumption; in asset markets items are purchased for their potential to change price; making the nature of how the markets’ participants respond to price changes fundamentally different.

-- 《The Origin of Financial Crises》