The argument is here.

I don’t think that the future is going to resemble the past. That doesn’t mean I’m out of stocks, but I’m not going to buy an index fund the way I used to. I think a lot of industries that are represented in the major stock indexes will not be there when the long slump is over with. I currently think that I can beat index investing over a ten-year horizon. We’ll see. I don’t yet see which companies or industries I want to bet on. But I know I don’t want to bet on financials or old media companies.

I should point out that the informal consensus among those at the Kauffman forum this past weekend is that Hamilton writes the most valuable posts of any economics blogger. He really puts a of analytics into what he writes, and he makes himself clear to the layman (Although the post I just linked to has some equations that could scare you, my guess is that you could follow the point even if you could not follow the math).

The folks who I would miss the most if they left the blogosphere would be Hamilton, Tyler Cowen, and Mark Thoma, all for different reasons.