On Luck versus Skill When Performance Benchmarks are Style-Consistent

Abstract

We firmly believe that style-appropriate, investible benchmarks not only provide a more parsimonious way of describing manager performance, but also that their use better aligns performance evaluation with the real world performance targets of fund managers’. It is against such benchmarks that managers should be judged. With this principle foremost in our approach, we use style-consistent benchmarks to determine whether any observed alpha produced by a sample of U.S. equity funds is due to skill or to luck. We find that different segments of the market, ranging from large-cap growth to small-cap value, exhibit different levels of skill and luck. Our results also show that the use of standard multi-factor models underestimates managerial ability and overstates the proportion of funds whose abnormal performance can be attributed to chance rather than to skill, when compared against the use of style-consistent practitioner benchmarks. We also find that a single factor performance evaluation model that uses Russell style indices consistent with the style orientation of a fund and market practice provides a parsimonious way of accounting for fund performance. Finally, our findings should be of particular relevance in mutual fund markets where the risk factors commonly used in the academic literature to evaluate manager performance – SMB, B/M, MOM and others – are not readily available.

Keywords: Mutual fund performance, style benchmarks, skill versus luck

JEL Classification: G1