We study the perfect Bayesian equilibrium of a model of learning over a general social network. Each individual receives a signal about the underlying state of the world, observes the past actions of a stochastically-generated neighborhood of individuals, and chooses one of two possible actions....

Most economic analyses presume that there are limited differences in the prior beliefs of individuals, as assumption most often justified by the argument that sufficient common experiences and observations will eliminate disagreements. We investigate this claim using a simple model of Bayesian...

In this paper we analyze the problem of whether and/or when to replace a leader (agent) when no monetary rewards are available, and it is the leader's competence rather than effort that is being evaluated. The only decisions that the leader takes over time are whether to undertake risky but...

This paper offers an introduction to game theory for applied economists. I try to give simple definitions and intuitive examples of the basic kinds of games and their solution concepts. There are four kinds of games: static or dynamic, and complete or incomplete information. ( Complete...

This paper studies policy in a class of economies in which information about commonly-relevant fundamentals -- such as aggregate productivity and demand conditions -- is dispersed and can not be centralized by the government. In these economies, the decentralized use of information can fail to...

This paper examines equilibrium and welfare in a tractable class of economies with externalities, strategic complementarity or substitutability, and incomplete information. In equilibrium, complementarity amplifies aggregate volatility by increasing the sensitivity of actions to public...

This paper examines the ability of a policy maker to control equilibrium outcomes in an environment where market participants play a coordination game with information heterogeneity. We consider defense policies against speculative currency attacks in a model where speculators observe the...

In recent years there has been a growing interest in macro models with heterogeneity in information and complementarity in actions. These models deliver promising positive properties, such as heightened inertia and volatility. But they also raise important normative questions, such as whether...

If an investor wants to form a portfolio of risky assets and can exert effort to collect information on the future value of these assets before he invests, which assets should he learn about? The best assets to acquire information about are ones the investor expects to hold. But the assets the...

R&D-intensive firms such as biotechnology and pharmaceutical companies follow very different corporate financial policies from firms in less R&D-intensive industries. To account for these differences, we propose an equilibrium model for such firms in which their capital structure, amount of R&D...