Information Cascades and Social Learning

Abstract

An information cascade is a situation in which an agent who observes others chooses the same action irrespective of the value of the agent’s private information signal. Theoretical models have found that cascades result in poor information aggregation, inaccurate decisions, and fragility of mass behaviors. We review the theory of information cascades and social learning. Our goal is to describe in a relatively integrated and accessible way the more important themes, insights and applications of the literature as it has developed over the last thirty years. We also highlight open questions and promising directions for further theoretical and empirical exploration. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.