Divergence in credit ratings

Abstract

During the recent credit crisis credit rating agencies (CRAs) became increas- ingly lax in their rating of structured products, yet increasingly stringent in their rating of corporate bonds. We examine a model in which a CRA operates in both the market for structured products and for corporate debt, and shares a common reputation across the two markets. We find that, as a CRA s reputation becomes good enough, it can be optimal for it to infl ate its ratings with probability one in the structured products market, but in flate its ratings with a probability zero in the corporate bond market.