How do independent directors view powerful CEOs? Evidence from a quasi-natural experiment

Prior research shows that powerful CEOs can exacerbate the agency conflict, resulting in adverse corporate outcomes. Exploiting an exogenous shock introduced by the passage of the Sarbanes-Oxley Act, we explore whether board independence mitigates CEO power. Based on difference-in-difference estimation, our evidence shows that independent directors view powerful CEOs unfavorably. Board independence diminishes CEO power by more than a quarter. Based on a quasi-natural experiment, our research design is less vulnerable to the omitted-variable bias and reverse causality and therefore suggests that the effect of board independence on CEO power is likely causal.