Information content of credit rating affirmations

We examine the economic determinants and informational effects of credit rating affirmations (i.e., the reiteration of past credit ratings) for a sample of US public firms from 1995 to 2020. We find that credit rating affirmations typically follow major corporate events and changes in firm fundamentals that increase information uncertainty about a firm's creditworthiness, suggesting that affirmations reduce uncertainty. We further document that rating affirmations provide value-relevant information to equity and debt investors. Using a short-window event study method, we show that equity investors react positively to rating affirmations and that information uncertainty around affirmations diminishes. These findings are more pronounced for firms with non-investment-grade ratings. We further show that our results strengthen for firms with greater pre-affirmation information uncertainty. Finally, consistent with our information uncertainty reduction results from the stock market, we report that bond yield spreads decrease for affirmed firms. Again, the effect is more pronounced for firms with non-investment-grade ratings. In summary, we highlight the significant capital markets' effects of credit rating affirmations, an area that the literature has largely ignored.