Classical economic theory assumes that individuals are super-humans with perfect calculation skills and a stable system of preferences. They decide by maximizing their expected utility. In practice, the decisions of “normal” people are affected by a combination of social, psychological and cognitive influences. In this course, we will see theories about how real-world decisions are made (e.g. prospect theory, bounded rationality, herding, self-control) and investigate how this affects the financial market (e.g. market efficiency and limits to arbitrage). We will study the implications for both individual decision makers and policy makers. We will study the use of behavioral finance for designing digital choice architectures. Importantly, through this course, you will understand better your own decision making and how to take into account the mental mistakes of others. The course is interdisciplinary and combines elements from economics and finance, with psychology, sociology and statistics.