When people don’t pay the true cost of something, they tend to consume it inefficiently.

The key to learning is feedback. It is nearly impossible to learn anything without it.

An incentive is a bullet, a key: an often tiny object with astonishing power to change a situation

The data don't lie: a Chicago street prostitute is more likely to have sex with a cop than to be arrested by one.

As W.C. Fields once said: a thing worth having is a thing worth cheating for.

The conventional wisdom is often wrong.

Many of life's decisions are hard. What kind of career should you pursue? Does your ailing mother need to be put in a nursing home? You and your spouse already have two kids; should you have a third?such decisions are hard for a number of reasons. For one the stakes are high. There's also a great deal of uncertainty involved. Above all, decisions like these are rare, which means you don't get much practice making them. You've probably gotten good at buying groceries, since you do it so often, but buying your first house is another thing entirely.