We study optimal fiscal and redistributive policies in an open economy without commitment. Due to its redistributive motives, the government's incentive to default on its external debt is affected by inequality. We show that in equilibrium the economy endogenously fluctuates between two regimes....

We propose a new business cycle theory. Firms need to randomize over firing or keeping workers who have performed poorly in the past, in order to give them an ex-ante incentive to exert effort. Firms have an incentive to coordinate the outcome of their randomizations, as coordination allows them...

We study the optimal provision of insurance against unobservable idiosyncratic shocks in a setting in which a benevolent government cannot commit. A continuum of agents and the government play an infinitely repeated game. Actions of the government are constrained only by the threat of reverting...

A planner sets a lump sum transfer and a linear tax on labor income in an economy with incomplete markets, heterogeneous agents, and aggregate shocks. The planner's concerns about redistribution impart a welfare cost to fluctuating transfers. The distribution of net asset holdings across agents...

This paper studies the optimal redistribution of income inequality in a model with search and matching frictions in the labor market. We study this problem in the context of a directed search model of the labor market populated by homogeneous workers and heterogeneous firms. The optimal...

We consider optimal joint nonlinear earnings taxation of couples. We use multi-dimensional mechanism design techniques to study this problem and show that the first-order approach - that restricts attention to only local incentive constraints - is valid for a broad set of primitives. Optimal...

We develop a unified framework for optimally managing public portfolios for a class of macro-finance models that include widely-used specifications for households' risk and liquidity preferences, market structures for financial assets, and trading frictions. An optimal portfolio hedges...

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...

The paper develops a general methodology for analyzing policies with path-dependency (hysteresis) in stochastic models with forward looking optimizing agents. Our main application is a macro-climate model with a path-dependent climate externality. We derive in closed form the dynamics of the...

We fully solve an assignment problem with heterogeneous firms and multiple heterogeneous workers whose skills are imperfect substitutes, that is, when production is submodular. We show that sorting is neither positive nor negative and is characterized sufficiently by two regions. In the first...