The Economic Impact of Mutual Fund Investor Behaviors

Abstract

This study analyzes how equity mutual fund investor behavior has changed over time, and the associated impact on investor returns. First, we find that from 1991-2016 investor return-chasing behavior declined and more recently disappeared, while investor flows have become more sensitive to expenses, past risk and alpha. We also present evidence that these changes correspond to changes in word usage and attention to alphas, past returns and fund expenses in the popular press and academic journals. Investors now pay more attention to fund characteristics that have the potential to improve future performance (e.g. risk, alpha and expenses), and less attention to characteristics that don’t (e.g. past returns). Second, we examine the effect of increased attention to fund alphas on investors’ realized performance. We confirm the well-documented positive persistence of alpha, but note that this positive cross-sectional persistence in alphas measures the net effect of two distinct phenomena: the cross-sectional variation in average alphas across funds (Harvey and Liu, 2018), and the time-series autocorrelation of alpha within each fund. Both properties are independently relevant: fund selection relates to investors’ ability to exploit variation in alphas across funds; timing relates to the ability to exploit the autocorrelation patterns within a given fund. We show that at the fund level, alphas have strong negative serial correlation. Lastly we decompose total mutual fund investor Performance Gap into fund selection and timing components, then further decompose each of these into pieces related to each individual determinant of the cashflow, so that we can determine how much each individual behavior contributes to both fund selection and timing. Even though investors realize some benefit from selecting high-alpha funds (smart money), they time their cash flows very poorly by investing in those funds after periods with the highest realized alphas (dumb money). The dumb money effect dominates, and we show that chasing alphas reduces investor returns by three times as much as chasing past returns. Overall, our results suggest that mutual fund investors have learned that alpha is important, but have not yet learned how to effectively integrate this knowledge into their investment decisions.