(MONEY Magazine) – That's the big issue in a tussle between the Investment Company Institute, the fund industry's lobbyist, and two academics whose fund research has given New York State attorney general Eliot Spitzer Ammo in his assault on fees. The profs' 2001 University of Iowa law journal article argues that investors in large-cap mutual funds are paying more than twice what pension funds are for stock-picking services. Why? Because pension funds negotiate with outside advisers to get the lowest fees, while mutual funds, whose boards are dominated by the advisory firms hired to run the funds, essentially negotiate with themselves. In January, the ICI blasted the Iowa paper and issued its own study claiming that mutual funds and pension funds pay similar amounts for similar services. While data on fund expenses are murky at best, the ICI's would-be rebuttal, based on an unrepresentative subset of funds, isn't convincing. Of course, investors don't need to wait for the dust to settle before lodging their own protest against excessive fees--by moving into cheaper funds. --DAVID FUTRELLE