Behavioral economists have shown that a sizable percentage of people are willing to pay real money to punish people who are taking from a common pot but not contributing to it. Just to insure that shirkers get what they deserve, we are prepared to make ourselves poorer.

Self-dealing, essentially, occurs when managers run companies to line their own pockets instead of those of the companies' owners. It's been a perennial problem in American capitalism and became a real dilemma when America moved toward a model in which corporations would be run by professional managers who had only small ownership stakes.

I do think that procrastination evolved in humans for good reasons. If you're trying to stay alive as a human being on the savanna 20,000 years ago, worrying about what's right behind that bush is a lot more important than worrying about what might happen three weeks from now.

The smartest groups, then, are made up of people with diverse perspectives who are able to stay independent of each other. Independence doesn't imply rationality or impartiality, though. You can be biased and irrational, but as long as you're independent, you won't make the group any dumber.

The important thing about groupthink is that it works not so much by censoring dissent as by making dissent seem somehow improbable.

Intellectual-property rules are clearly necessary to spur innovation: if every invention could be stolen, or every new drug immediately copied, few people would invest in innovation. But too much protection can strangle competition and can limit what economists call 'incremental innovation' - innovations that build, in some way, on others.

Discussions of health care in the U.S. usually focus on insurance companies, but, whatever their problems, they're not the main driver of health-care inflation: providers are.