This paper investigates whether CEO pay disparity reflects efficient contracting or managerial power by exploiting a quasi-natural experiment which mandated option expensing, FASB ASC 718. We find supportive evidence for the managerial power hypothesis. Relative to low pay disparity firms, firms characterized by high pay disparity exhibit a significantly larger decline in options pre- versus post-expensing. Further, high pay disparity firms are found to replenish their compensation with cash-based rather than other equity-based pay. Our findings suggest CEOs in high pay disparity firms exploited the free accounting cost of options to inflate their pay rather than for their incentive properties.