For these banks, their tests reveal that banks’ credit ratings indeed include valuable private information from monitoring, as theory suggests. However, their tests also reveal that publicly available information from a credit bureau is not efficiently impounded in the bank ratings: The credit bureau ratings not only predict future movements in the bank ratings but also improve forecasts of bankruptcy and loan default. The authors investigate possible explanations for these findings. Their results are consistent with bank loan officers placing too much weight on their private information, a form of overconfidence. To the extent that overconfidence results in placing too much weight on private information, risk analyses of the bank loan portfolios in the authors' data could be improved by combining the bank credit ratings and public credit bureau ratings.
Credit Ratings and Bank Monitoring Ability
WP 13-21 - In this paper the authors use credit rating data from two large Swedish banks to elicit evidence on banks’ loan monitoring ability.