The arrival of new, unfamiliar, investment opportunities is often associated with "exuberant" movements in asset prices and real economic activity. During these episodes of high uncertainty, financial markets look at the real sector for signals about the profitability of the new investment...

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 shows how rational investors can have different degrees of optimism regarding the prospects of the economy, even if they share exactly the same information regarding all economic fundamentals. The key is that heterogeneity in expectations regarding endogenous outcomes can emerge as a...

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...