Using the passage of the Sarbanes-Oxley Act and the associated change in listing standards as a natural experiment, we find that while board independence decreases the cost of debt when credit conditions are strong or leverage low, it increases the cost of debt when credit conditions are poor or...

Using the Sarbanes-Oxley Act of 2002 as a natural experiment, we document a non-monotonic relation between board independence and credit ratings. Ratings are upgraded with an exogenous increase of board independence only when independence is low, which is consistent with the costs as well as...