A wide range of interventions, from subsidized grains all the way to conditions on nutrition in conditional cash transfers, have either been tried or put in place in different countries in order to fight under-nutrition. A number of important policy experiments in recent years, directly or...

We study optimal monetary policy in an environment in which firms' pricing and production decisions are subject to informational frictions. Our framework accommodates multiple formalizations of these frictions, including dispersed private information, sticky information, and certain forms of...

We study the Ramsey policy problem in an economy in which firms face a collateral constraint. Issuing more public debt alleviates this friction by increasing the aggregate quantity of collateral. In so doing, however, the issuance of more debt also raises interest rates, which in turn increases...

This paper augments the neoclassical growth model to study the macroeconomic effects of idiosyncratic investment risk. The general equilibrium is solved in closed form under standard assumptions for preferences and technologies. Relative to complete markets, the steady state is characterized by...

We enrich workhorse macroeconomic models with a mechanism that proxies strategic uncertainty and that manifests itself as waves of optimism and pessimism about the short-term economic outlook. We interpret this mechanism as variation in confidence and show that it helps account for many salient...

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...

Coordination models have been used in macroeconomics to study a variety of crises phenomena. It is well understood that, in these models, aggregate fluctuations can be purely self-fulfilling. In this paper I highlight that cross-sectional heterogeneity in expectations regarding the endogenous...

This chapter studies how incomplete information helps accommodate frictions in coordination, leading to novel insights on the joint determination of expectations and macroeconomic outcomes. We review and synthesize recent work on global games, beauty contests, and their applications. We...

We consider a class of convex, competitive, neoclassical economies in which agents are rational; the equilibrium is unique; there is no room for randomization devices; and there are no shocks to preferences, technologies, endowments, or other fundamentals. In short, we rule out every known source...

Financial markets look at data on aggregate investment for clues about underlying profitability. At the same time, firms' investment depends on expected equity prices. This generates a two-way feedback between financial market prices and investment. In this paper we study the positive and...