I apply standard time series models to US housing prices. Forecasts made in 2005 or earlier would have produced stress scenarios that are worse than the subsequent actual change in housing prices. The probability of these scenarios is in the range that banks claim to consider in their risk...

This paper shows that the stock price of the rating agency Moody’s reacts negatively to ratingactions that are perceived to indicate low rating quality. The reaction is economicallysignificant. The cumulative effect corresponds to a 20% loss in market capitalization. Thissuggests that market...

Rating agencies claim to look through the cycle when assigning corporate credit ratings,which entails that they are able to separate trend components of default risk from transitoryones. To test whether agencies possess this competence, I take market-based estimates of oneyeardefault...

Rating agencies state that they take a rating action only when it is unlikely to bereversed shortly afterwards. Using a formal representation of the rating process, I showthat such a policy provides a good explanation for the empirical evidence: ratingchanges relatively seldom occur, they...

Using a structural model of default, I derive rating characteristics if ratings are meant tolook ‘through the cycle’ as opposed to being based on the borrowers’ current condition.The through-the-cycle method, which is employed by most rating agencies, requires aseparation of permanent and...

This paper uses Monte Carlo simulations to assess the impact of noisy inputparameters on the accuracy of estimated portfolio credit risk. Assumptionsabout input quality are derived from the distribution of historical samplestatistics commonly used in default risk modelling. The resulting...