Determinants of cost efficiencies in the mutual fund industry

We evaluate determinants of cost efficiencies in the U.S. mutual fund industry for 1998-2003. Our empirical results show that cost increases in this industry have been less than proportional to increases in assets. We find that funds without a 12b-1 plan show larger economies of scale than funds with a 12b-1 plan; institutional funds show greater economies of scale than do retail funds; and that fund families that are more focused in their investment objectives reap benefits of lower fund management costs than do fund families that are more diversified in their investment objectives.