Economists like to base their theories on individual decision making. Individuals, the idea goes, have their own interests and preferences, and if we don’t include these in our theory we can’t be sure how people will react to changes in their economic circumstances and policy. While there may be social influences, in an important sense the buck stops with individuals. Understanding how individuals process information to come to decisions about their health, wealth and happiness is crucial. You can count me as someone who thinks that on the whole, this is quite a sensible view.