This paper uses a large sample containing the complete return histories of 2300UK openended mutual funds over a 23-year period to measure fund performance. We find some evidence of underperformance on a risk-adjusted basis by the average fund manager, persistenceof performance and the existence of a substantial survivor bias. Similar findings have been reported for US equity mutual funds. New findings not previously documented for other markets include evidence that mutual fund performance varies substantially across different asset categories, especially foreign asset categories. We also identify some new patterns in performance related to the funds' distance from their inception and termination dates: underperformance intensifies as the fund termination date approaches, while, in contrast, there is some evidence that funds (weakly) outperform during their first year of existence.

Most empirical studies suggest that mutual funds do not persistently outperform an appropriate benchmark in the long run. We analyze this lack of persistence in terms of two equilibrating mechanisms: fund flows and manager changes. Using data on actively managed US equity mutual funds, we find that if neither mechanism is operating, winner funds (top-decile ranked in previous year) continue to significantly outperform loser funds (bottom-decile ranked in previous year) by 4.08 percentage points per annum. However, the difference between previous winner and loser funds declines to zero within one year if the two mechanisms are acting together. Thus, equity mutual fund out- and underperformance are unlikely to persist in well-functioning financial markets.

We compare two bootstrap methods for assessing mutual fund performance. The first produces narrow confidence intervals due to pooling over time, whereas the second produces wider confidence intervals because it preserves the cross correlation of fund returns. We then show that the average U.K. equity mutual fund manager is unable to deliver outperformance net of fees under either bootstrap. Gross of fees, 95% of fund managers on the basis of the first bootstrap and all fund managers on the basis of the second bootstrap fail to outperform the luck distribution of gross returns.

We show a positive relation between network centrality and risk-adjusted performance in a delegated investment management setting. More connected managers take more portfolio risk and receive higher investor flows, consistent with these managers improving their ability to exploit investment opportunities through their network connections. Greater network connections are shown to be particularly important in reducing the diseconomies of scale for large managers who are well connected. We also use the exogenous merger of two investment consultants, which creates a sudden change in the network connections of the managers they oversee, to provide evidence that a greater number of connections translates into better portfolio performance.

Using a unique data set, we document two secular trends in the shift from centralized to decentralized pension fund management over the past few decades. First, across asset classes, sponsors replace generalist balanced managers with better‐performing specialists. Second, within asset classes, funds replace single managers with multiple competing managers following diverse strategies to reduce scale diseconomies as funds grow larger relative to capital markets. Consistent with a model of decentralized management, sponsors implement risk controls that trade off higher anticipated alphas of multiple specialists against the increased difficulty in coordinating their risk‐taking and the greater uncertainty concerning their true skills.