Humans just aren't entirely rational creatures. We decide to roll over and hit the snooze button instead of going to the gym. We take out home loans we can't possibly afford. And did you know that people named Paul are more likely to move to St. Paul than other cities? All too often, our subconscious causes us to act against our own self-interest. But our free-market economy is based on the assumption that we always do act in our own self-interest...