This paper explores the economic role credit rating agencies play in the corporate bond market. We consider three existing theories about multiple ratings: information production, rating shopping, and regulatory certification. Using differences in rating composition, default prediction, and credit spread changes, our evidence only supports regulatory certification. Marginal, additional credit ratings are more likely to occur because of, and seem to matter primarily for, regulatory purposes. They do not seem to provide significant additional information related to credit quality.

We derive an equilibrium asset pricing model incorporating liquidity risk, derivative assets, and short-selling due to hedging of non-traded risk. We show that, both for positive-net-supply assets and derivatives, the sign of liquidity effects depends on investor heterogeneity in non-traded risk exposure, risk aversion, horizon and wealth. We also show that liquidity risk affects derivatives in a different way than positive-net-supply assets. We estimate this model for the credit default swap market using GMM. We find strong evidence for an expected liquidity premium earned by the credit protection seller. The effect of liquidity risk is significant but economically small.