The concept of first-order stochastic dominance defined on distributions is inadequate in models with learning. We extend this concept to the space of distributions on distributions. We discuss conditions under which for all common observations one person's beliefs (over a set of probability...

The sequential search problem, without the assumption that the searcher knows the underlying distribution, is investigated. Both search with recall and without recall are examined. Sufficient conditions for the existence of optimal stopping rules with the reservation property are provided....

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...

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...