Measuring the True Cost of Active Management by Mutual Funds

Ross M. Miller

Volume 5, Number 1, First Quarter 2007

This article derives a rigorous method for allocating fund expenses between active and passive management and that enable one to compute the implicit cost of active management. Computing this “active expense ratio” requires only a fund’s published expense ratio, its R-squared relative to a benchmark index, and the expense ratio for a competitive fund that tracks that index. This method is then applied to the Morningstar universe of large-cap mutual funds and active expense ratios are found to average more than 7%. The cost of active management for other classes of mutual funds is also found to substantial.