Peter Lückoff investigates why fund flows and manager changes act as equilibrium mechanisms and drive the performance of both previously outperforming and previously underperforming funds back to average levels.

This paper adapts the model of Berk and Green (2004) to explain with reasonable success the data on mutual fund returns and flows. Using a Bayesian measure of fund-manager skill that controls for fund flows, I find that posterior estimates of skill vary substantially in the cross section and that perceived differences in ability persist through time. Consistent with the model, investor fund flows respond in a convex manner to posterior updates of manager skill scaled by functions of the expense ratio, and this result is robust after including a convex function of past performance. While cross-sectional variation in posterior skill estimates has predictive power for out-of-sample subsequent fund performance, such predictability is present only in the short run. Beyond one year, high-skilled managers do not consistently out-perform low-skilled managers as skill-chasing fund flows equalize the realized abnormal fund returns across managers. Overall, my empirical evidence is consistent with some managers possessing high ability, investors rationally chasing returns generated by those managers, and lack of long-run persistence in fund returns due to equilibrating fund flows and diseconomies of scale in assets under management. Outside of the model, I show that the cross-sectional distribution of managerial ability is related to fund style and fund-manager compensation in a way that is consistent with matching the managerial productivity to the nature of the underlying portfolio.

We document that the observed persistence amongst the worst performing actively managed mutual funds is attributable to funds that have performed poorly both in the current and prior year. We demonstrate that this persistence results from an unwillingness of investors in these funds to respond to bad performance by withdrawing their capital. In contrast, funds that only performed poorly in the current year have a significantly larger (out)flow of funds/return sensitivity and consequently show no evidence of persistence in their returns.

We document that the observed persistence amongst the worst performing actively managed mutual funds is attributable to funds that have performed poorly both in the current and prior year. We demonstrate that this persistence results from an unwillingness of investors in these funds to respond to bad performance by withdrawing their capital. In contrast, funds that only performed poorly in the current year have a significantly larger (out)flow of funds/return sensitivity and consequently show no evidence of persistence in their returns.