Campaigns fail if they waste resources courting voters who are unpersuadable or already persuaded. Their most urgent task is to find and persuade the few voters who are genuinely undecided and the larger number who are favorably disposed but need a push to actually vote.

Auto repair, piloting, skiing, perhaps even management: these are skills that yield to application, hard work, and native talent. But forecasting an uncertain future and deciding the best course of action in the face of that future are much less likely to do so. And much of what we've seen so far suggests that a large group of diverse individuals will come up with better and more robust forecasts and make more intelligent decisions than even the most skilled "decision maker."

The problem is that groups are only smart when the people in them are as independent as possible. This is the paradox of the wisdom of crowds.

The reason advertising is governed by fear, after all, is that most agencies rely on just a few clients to bring in the lion's share of their revenues.

In industries where a lot of competitors are selling the same product - mangoes, gasoline, DVD players - price is the easiest way to distinguish yourself. The hope is that if you cut prices enough you can increase your market share, and even your profits. But this works only if your competitors won't, or can't, follow suit.

It may be that the very qualities that help people get ahead are the ones that make them ill-suited for managing crises. It's hard to prepare for the worst when you think you're the best.

Publishers, naturally, loathe used books and have developed strategies to depress the secondhand market. They bring out new, even more expensive editions of popular textbooks every three to four years, in a classic cycle of planned obsolescence.