Mark Hulbert discussed an interesting new study in Sunday's New York Times. He sums it up: "Don't even consider holding actively managed mutual funds unless you're willing to switch funds often. All other fund investors should simply buy and hold an index fund for the long term."

The author of the study argues that mutual funds underperform over the long-term not because of the inability of professional managers to pick stocks, but because of the way money flows into funds affects returns. That's right! Blame yourself for the poor performance of your funds! Basically, Jonathan Berk, the University of California professor who wrote the paper, argues that managers who perform well attract greater investments and so the funds stop performing well.

The professor suggests a complicated method of checking your funds regularly and selling bottom-performing funds and buying top-performing ones -- sounds to me a lot like performance-chasing. It also seems to run contrary to Berk's complaint that managers who perform well take on too much in the way of assets. Isn't performance-chasing what causes that problem?

Particularly given the costs of switching funds frequently (mainly taxes), I think investors will still do far better owning index funds. It's a lot easier too, isn't it?