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.

Disasters redistribute money from taxpayers to construction workers, from insurance companies to homeowners, and even from those who once lived in the destroyed city to those who replace them. It's remarkable that this redistribution can happen so smoothly and quickly, with devastated regions reinventing themselves in a matter of months.

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.

All things being equal, letting people make decisions for themselves will produce smarter outcomes, collectively, than relying on government planners.

If army ants are wandering around and they get lost, they start to follow a simple rule:Just do what the ant in front of you does. The ants eventually end up in a circle. There's this famous example of one that was 1,200 feet long and lasted for two days; the ants just kept marching around and around in a circle until they died.

Addictive behavior is kind of the inverse of procrastination: procrastination is about not being able to do what you want to do, addiction about not being able to not do what you don't want to do (drink, use drugs, etc.)

If you work for Google or Apple, stock options give you a chance to share in the increasing value of the company. In the N.F.L., nothing like this happens; the players, though rich, are just working stiffs like the rest of us.