We empirically analyze the nature of returns to scale in active mutual fund management. We find strong evidence of decreasing returns at the industry level: As the size of the active mutual fund industry increases, a fund’s ability to out- perform passive benchmarks declines. At the fund...

We find that active mutual funds perform better after trading more. This time-series relation between a fund’s turnover and its subsequent benchmark-adjusted return is especially strong for small, high-fee funds. These results are consistent with high-fee funds having greater skill to identify...