Until about twenty years ago, the consensus view on the cause of financial-system distress was fairly simple: a run on one bank could easily turn to a panic involving runs on all banks, destroying some and disrupting the financial system. Since then, however, a series of events—such as...

Now in prospect is a major revision of international bank capital regulations that would embody recent advances in credit risk measurement and management. Previous regulations have been simpler in structure, with a primary goal of getting capital requirements right on average, and thus have...