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

If someone really wants my company's business, why shouldn't he be able to do everything he can - including paying me off - to get that business? Because bribery encourages people to make decisions based on the wrong criteria, which means in the business world that it distorts the efficient allocation of resources.

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.

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.

Under the right circumstances, groups are remarkably smart - smarter even sometimes than the smartest people in them.

Corporations hope that the right concept will turn things around overnight. This is what you might call the crash-diet approach: starve yourself for a few days and you'll be thin for life.

Bubbles and crashes are textbook examples of collective decision making gone wrong. In a bubble, all of the conditions that make groups intelligent - independence, diversity, private judgement-disappear.