Structural Shifts in Credit Rating Standards

I examine the time‐series variation in corporate credit rating standards from 1985 to 2007. A divergent pattern exists between investment‐grade and speculative‐grade rating standards from 1985 to 2002 as investment‐grade standards tighten and speculative‐grade loosen. In 2002, a structural shift occurs toward more stringent ratings. Holding characteristics constant, firms experience a drop of 1.5 notches in ratings due to tightened standards from 2002 to 2007. Credit spread tests suggest that the variation in standards is not completely due to changes in the economic climate. Rating standards affect credit spreads. Loose ratings are associated with higher default rates.     

Fire Sales in a Model of Complexity

We present a model of financial crises that stem from endogenous complexity. We conceptualize complexity as banks' uncertainty about the financial network of cross exposures. As conditions deteriorate, cross exposures generate the possibility of a domino effect of bankruptcies. As this happens, banks face an increasingly complex environment since they need to understand a greater fraction of the financial network to assess their own financial health. Complexity dramatically amplifies banks' perceived counterparty risk, and makes relatively healthy banks reluctant to buy risky assets. The model also features a novel complexity externality.