For decades credit rating agencies were viewed as trusted arbiters of creditworthiness and their ratings as important tools for managing risk. The common narrative is that the value of ratings has been compromised by the evolution of the industry to a form where issuers pay for ratings. In this...

What a country has done in the past, and what other countries are doing in the present can feedback for good or for ill. We develop a model which can address hysteresis and contagion in sovereign debt markets. When a country's fundamentals change, those changes affect information acquisition...

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...