The Dynamics of Social Norms presents a general framework for studying the dynamics of social norms: how they arise, why they persist, and what causes them to change. The aim is to show how social norms can be incorporated into economic analysis without giving up the idea that individuals act purposively and, for the most part, rationally. Over time their interactions produce complex dynamics in which norms emerge, persist for a time, and eventually dissipate or are displaced. The framework is applied to a wide variety of concrete examples, both contemporary and historical. These include changing dress codes, patterns of conspicuous consumption, compensation practices, tipping in restaurants, gender norms, female circumcision, voting rights, and many others. Young illustrates the diversity of norms that shape people's decisions, introduces a framework for analyzing their dynamics, and suggests what types of interventions would be most effective for eliminating harmful norms.