What is the nature of the crisis?

What is the nature of the crisis? The details can be insanely complex, but the basics are fairly simple. The bursting of the housing bubble has led to large losses for anyone who bought assets backed by mortgage payments; these losses have left many financial institutions with too much debt and too little capital to provide the credit the economy needs; troubled financial institutions have tried to meet their debts and increase their capital by selling assets, but this has driven asset prices down, reducing their capital even further.

这是我看到过的最言简意赅的描述此次的经济危机，Paul的这篇文章也很值得一读。

From PAUL KRUGMAN - 2008 Nobel Prize Winner

Reference: Gordon Does Good