My life has been, in part, a series of crusades. First I just wanted to understand as much as possible. Then I focused on big problems, wondering how to fix them. Digging deeper I was persuaded by economists: our key problems are institutional. Yes we can have lamentable preferences and cultures. But it is hard to find places to stand and levers to push to move these much, or even to understand the effects of changes. Institutions, in contrast, have specific details we can change, and economics can say which changes would help.