The Securities and Exchange Commission (SEC) sanctioned investor-paid rating agency Egan-Jones for falsely stating that it did not know its clients’ investment positions. The SEC’s action against Egan-Jones raises the broad question whether knowledge of clients’ investment positions creates a conflict of interest for investor-paid ratings. In an experimental setting, we find that investor-paid rating agencies are likely to assign credit ratings that are biased in favor of their clients’ positions, and that this effect is attenuated when the rated company (...) has a sophisticated investor base that is expected to scrutinize ratings. The effect is not conditional on the risk profile of the rated companies. Taken together, our findings suggest that a conflict of interest stemming from investors’ preferences is likely to bias ratings under investor-pays business models, but scrutiny by the company’s investor base can counteract this bias. (shrink)