Incentives

"Economics is, at root, the study of incentives: how people get what they want, or need, especially when other people want or need the same thing..... An incentive is a bullet, a lever, a key: an often tiny object with astonishing power to change a situation.... An incentive is simply a means of urging people to do more of a good thing and less of a bad thing. But most incentives dont come abou't organically... There are three basic flavours of incentive: economic, social, and moral."

- Steven D. Levitt & Stephen J. Dubner from the book Freakonomics