We characterize the optimal sequential choice of monetary policy in economies with either nominal or indexed debt. In a model where nominal debt is the only source of time inconsistency, the Markov-perfect equilibrium policy implies the progressive depletion of the outstanding stock of debt,...

When the zero lower bound on nominal interest rates binds, monetary policy cannot provide appropriate stimulus. We show that in the standard New Keynesian model, tax policy can deliver such stimulus at no cost and in a time-consistent manner. There is no need to use inefficient policies such as...

This paper investigates whether the quantity theory of money is still alive. We demonstrate three insights. First, for countries with low inflation, the raw relationship between average inflation and the growth rate of money is tenuous at best. Second, the fit markedly improves, when correcting...

We study the immigration policy that maximizes the welfare of the native population in an economy where the government designs an optimal redistributive welfare system and supplies public goods. We show that when the government can design different tax systems for immigrants and natives, free...

Using a quantitative model that features technical progress in automation and endogenous skill choice, we show that, given the current U.S. tax system, a sustained fall in automation costs can lead to a massive rise in income inequality. We characterize the optimal tax system in this model. We...

Over the last three decades there has been a dramatic increase in the size of the financial sector and in the compensation of financial executives. This increase has been associated with greater risk-taking and the use of more complex financial instruments. Parallel to this trend, the...

We study how barriers to competition---such as restrictions to business start-up and strict enforcement of covenants or IPR---affect the investment in knowledge capital when contracts are not enforceable. These barriers lower the competition for human capital and reduce the incentive to...

We study a general equilibrium model in which entrepreneurs finance investment with optimal financial contracts. Because of enforceability problems, contracts are constrained efficient. We show that limited enforceability amplifies the impact of technological innovations on aggregate output....

We show that credit crises can be Self-Confirming Equilibria (SCE), which provides a new rationale for policy interventions like, for example, the FRB's TALF credit-easing program in 2009. We introduce SCE in competitive credit markets with directed search. These markets are efficient when...

We develop an equilibrium search-matching model with risk-neutral agents and two-sided ex-ante heterogeneity Unemployment insurance has the standard effect of reducing employment, but also helps workers to get a suitable job. The predictions of our simple model are consistent with the...