Instruments for credit risk transfer arise endogenously from and interact with optimizing behavior of their users. This is particularly true with credit derivatives which are usually OTC contracts between banks as buyers and sellers of credit risk. Recent literature, however, does not account...

Rating downgrades are known to make subsequent downgrades more likely. We analyze the impact of this 'downward momentum' on credit portfolio risk. Using S&P ratings from 1996 to 2005, we estimate a transition matrix that is insensitive to and a second matrix that is sensitive to previous...