How do changes in a rating agency's reputation affect the ratings market? We study the dynamics of credit ratings after Standard & Poor's (S&P) was shut out of a large segment of the commercial mortgage-backed securities (CMBS) ratings market following a procedural mistake. Exploiting the fact that most CMBS have ratings from multiple agencies, we show that S&P subsequently eased its standards compared to other raters. This coincided with a partial recovery in the number of deals S&P was hired to rate. Our findings suggest that an agency can regain market share after suffering reputational damage by issuing optimistic ratings.

Rating agencies produce ratings used by investors, but obtain most of their revenue from issuers, leading to a conflict of interest. We employ a unique data set on the use of non-rating services, and the associated payments, in India, to test if this conflict affects ratings quality. Agencies rate issuers that pay them for non-rating services higher (than agencies not hired for such services). Such issuers also have higher default rates. Both effects are increasing in the amount paid. These results suggest that issuers which hire agencies for non-rating services receive higher ratings despite having higher default risk.