Cross-Sectional Alpha Dispersion and Performance Evaluation

Abstract

Our paper explores the link between cross-sectional fund return dispersion and performance evaluation. The foundation of our model is the simple intuition that in periods of high return dispersion, which is associated with high levels of idiosyncratic risk for zero-alpha funds, it is easier for unskilled managers to disguise themselves as skilled. Rational investors should be more skeptical and apply larger discounts to reported performance in high dispersion environments. Our empirical results are consistent with this prediction. Using fund flow data, we show that a one-standard deviation increase in cross-sectional return dispersion is associated with an 11% to 17% decline in flow-performance sensitivity. The effect is stronger for recent data and among outperforming funds.

Keywords: Alpha, Investor behavior, Hedge funds, Mutual funds, Performance evaluation, Portfolio management, Risk, Type I errors, Type II errors, Bayesian decision-making, Appraisal ratio, Flow-performance sensitivity, Idiosyncratic risk

JEL Classification: G11, G14, G23