Why do people buy the stuff they buy? In classical economics, most models assume that consumers behave rationally. As you've probably noticed in your real life, in case after case, people don't actually make rational decisions. There can be emotional or social reasons for all this irrationality, and behavioral economics tries to address this. We'll talk about risk, nudge theory, prices and perception, and the ultimatum game. So, let's get irrational, in a logical way, of course.