Would a mutual fund manager to better with $1 billion or $100 million?

[Jeffmet3]

I was talking to someone at work about this today, and to me, it seemed to make sense that the same manager would have better results with the smaller fund, as it would allow him to be more agile as well as put more into what he considers his best options. Versus for a larger fund, it becomes more similar to an index and thus is handicapped by its size.

However, the person I work with disagreed and said that there's no evidence, and no reason to believe that.

I think my position makes sense, but can anyone else explain why either way?

thanks,

jeff