We develop a perturbational technique to approximate equilibria of a wide class of discrete-time dynamic stochastic general equilibrium heterogeneous-agent models with complex state spaces, including multi-dimensional distributions of endogenous variables. We show that approximating policy...

We study optimal monetary and fiscal policy in a model with heterogeneous agents, incomplete markets, and nominal rigidities. We develop numerical techniques to approximate Ramsey plans and apply them to a calibrated economy to compute optimal responses of nominal interest rates and labor tax...

The paper studies asset pricing in informationally decentralized markets. These markets have two key frictions: trading is decentralized (bilateral), and some agents have private information. We analyze how uninformed agents acquire information over time from their bilateral trades. In...

We study the constrained Pareto efficient allocations in a dynamic production economy in which the group that holds political power decides the allocation of resources. We show that Pareto efficient allocations take a quasi-Markovian structure and can be represented recursively as a function of...

We study the dynamic taxation of capital and labor in the Ramsey model under the assumption that taxes and public good provision are decided by a self-interested politician who cannot commit to policies. We show that, as long as the discount factor of the politician is equal to or greater than...

This paper studies a mechanism design model of financial intermediation. There are two informational frictions: agents receive unobservable shocks and can participate in markets by engaging in trades unobservable to intermediaries. Without regulations, intermediaries provide no risk sharing...

We study optimal tax policy in a dynamic private information economy with endogenous private markets. We characterize efficient allocations and competitive equilibria. A standard assumption in the literature is that trades are observable by all agents. We show that in such an environment the...

The paper analyzes an implementation of an optimal disability insurance system as a competitive equilibrium with taxes. The problem is modeled as a dynamic mechanism design problem in which disability is unobservable. We show that an asset-tested disability system in which a disability transfer...

In this paper, we generalize the notion of Pareto-efficiency to make it applicable to environments with endogenous populations. Two efficiency concepts are proposed, P-efficiency and A-efficiency. The two concepts differ in how they treat people who are not born. We show how these concepts...

This paper develops a model of a monetary economy in which individual firms are subject to idiosyncratic productivity shocks as well as general inflation. Sellers can change price only by incurring a real menu cost.' We calibrate this cost and the variance and autocorrelation of the...