This intelligence, or what I'll call "the wisdom of crowds," is at work in the world in many different guises. It's the reason the Internet search engine Google can scan a billion Web pages and find the one page that has the exact piece of information you were looking for. It's the reason it's so hard to make money betting on NFL games, and it helps explain why, for the past fifteen years, a few hundred amateur traders in the middle of Iowa have done a better job of predicting election results than Gallup polls have.

Of course, plenty of people don't think that guaranteeing affordable health insurance is a core responsibility of government.

Standards wars involve lots of variables, and understanding them often seems more an art than a science. They generally involve just two big players, and end in a winner-take-all situation.

The world's central banks and the International Monetary Fund still have vaults full of bullion, even though currencies are no longer backed by gold. Governments hold on to it as a kind of magic symbol, a way of reassuring people that their money is real.

Pop music thrives on repetition. You know a song's a hit when you've heard it so often that you'll be happy never to hear it again.

Speculators get a bad rap. In the popular imagination they're greedy, heedless, and amoral, adept at price manipulations and dirty tricks. In reality, they often play a key role in making markets run smoothly.

Markets work best when there's lots of information available and a historical track record to go on; they excel at predicting things like horse races, election outcomes, and box-office results. But they're bad at predicting things like who will be the next Supreme Court nominee, as that depends on the whim of the president.