This paper explores cross-sectional differences in the behavior and performance of mutual fund managers. The authors find that younger managers earn significantly higher returns than older managers, and that managers from more selective undergraduate institutions with higher SAT scores also earn higher returns. These differences are attributed to systematic variations in expense ratios, risk-taking behavior, and performance. Managers from higher SAT schools have higher risk-adjusted excess returns. The paper also examines the labor market for mutual fund managers, suggesting that managerial turnover is more performance-sensitive for younger managers. The authors conclude that some mutual fund managers are indeed better than others, and that this finding is consistent with the idea that asset markets have a small degree of equilibrium inefficiency.This paper explores cross-sectional differences in the behavior and performance of mutual fund managers. The authors find that younger managers earn significantly higher returns than older managers, and that managers from more selective undergraduate institutions with higher SAT scores also earn higher returns. These differences are attributed to systematic variations in expense ratios, risk-taking behavior, and performance. Managers from higher SAT schools have higher risk-adjusted excess returns. The paper also examines the labor market for mutual fund managers, suggesting that managerial turnover is more performance-sensitive for younger managers. The authors conclude that some mutual fund managers are indeed better than others, and that this finding is consistent with the idea that asset markets have a small degree of equilibrium inefficiency.