Whether CEO stock-based pay effectively enhances firm performancehas been a long time subject of debate for both academics and practitioners.Using a large quantity of U.S. S&P firm data for the years1993–2005, this study is one of the first to employ a conditional quantileregression to explore the changing distribution in firm RoE, bothacross firms and over time. Based on the robustness checks, we find that the empirical results inthis study are robust with respect to industrial and yearly controls. In addition, the impact of stock-based compensation on firm performanceincreases with firm profitability. This result also holds in the tests of market performance, Tobin’s q, as the dependent variable, or the payfor-performance sensitivity as the independent variable. Moreover, the use of a lagged stock-based/total