It’s often said that what our leaders need is common sense, not fancy theories. But common-sense ideas that work in individuals’ everyday lives are often useless for dealing with complex problems of society as a whole. For example, it’s common sense that government payments to the unemployed will lead to more jobs because those receiving the payments will spend the money, thereby increasing demand, which will lead businesses to hire more workers. But it’s also common sense that if people are paid for not working, they will have less incentive to work, which will increase unemployment. The trick is to find the amount of unemployment benefits that will strike the most effective balance between stimulating demand and discouraging employment. This is where our leaders need to talk to economists.