In this paper we present circumstances under which the possibility of high leverage can lead to widespread default and national crises. In models with incomplete markets, default and production, there will almost always be a mismatch between firm output across states of nature and asset...

In this paper we show that competitive equilibrium prices and margin requirements naturally lead to too much leverage relative to the constrained optimum. We describe two mechanisms through which equilibrium forces lead agents to borrow too much and to hold too little collateral. To illustrate...