Hello Richard,

Yes, Tom's research, along with that of others, demonstrates that active managers are actually quite good at security selection, but that they make poor portfolio management choices. See, for example, the interview I conducted with Tom last year that features his research. The detrimental bits of portfolio management are: asset bloat, closet indexing, and over-diversification. These data suggest a different diagnosis than the one popularly offered: humans are not good at investing, to humans have created a whacky culture that interferes with their abilities.

See you in Philly!

Jason