I blogged last month about Philip Tetlock's book Expert Political Judgment. Reviews of the book suggested that Tetlock's two main conclusions were:

1) Experts are really bad at making predictions; and

2) Experts who typified Isaiah Berlin's "hedgehogs" did far worse than those who were "foxes." (and no, that doesn't mean Salma Hayek or Scarlet Johansson -- we're talking about indifferent kinds of foxes here).

The New Yorker's review of [Tetlock's] book surveyed the grim state of expert political predictions and concluded by advising readers, "Think for yourself." Prof. Tetlock isn't sure he agrees with that advice. He pointed out an exercise he conducted in the course of his research, in which he gave Berkeley undergraduates brief reports from Facts on File about political hot spots, then asked them to make forecasts. Their predictions -- based on far less background knowledge than his pundits called upon -- were the worst he encountered, even less accurate than the worst hedgehogs. "Unassisted human intuition is a bomb here," Prof. Tetlock told me.