We revisit the question of how capital should be taxed, arguing that if governments are allowed to use the kinds of tax instruments widely used in practice, for preferences that are standard in the macroeconomic literature, the optimal approach is to never distort capital accumulation. We show that the results in the literature that lead to the presumption that capital ought to be taxed for some time arise because of the initial confiscation of wealth and because the tax system is restricted.

We study cooperative optimal Ramsey equilibria in the open economy addressing classic policy questions: Should restrictions be placed to free trade and capital mobility? Should capital income be taxed? Should goods be taxed based on origin or destination? What are desirable border adjustments? How can a Ramsey allocation be implemented with residence-based taxes on assets? We characterize optimal wedges and analyze alternative policy implementations.

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 wasteful public spending or future commitments to low interest rates.

We explore quantitatively the possibility of multiple equilibria in a model of sovereign debt crises. The source of multiplicity is the one identified by Calvo (1988). This type of multiplicity has been at the heart of the policy debate through the recent European sovereign debt crisis. Key for multiplicity in the model is a stochastic process for output featuring long periods of either high or low growth. We calibrate the output process in the model using data for the southern European countries that were exposed to the debt crisis. We find that expectations-driven sovereign debt crises are empirically plausible, but only in periods of stagnation. Multiplicity is state dependent: in periods of stagnation and for intermediate levels of debt, interest rates may be high for reasons unrelated to fundamentals.

We study a variation of the standard model of sovereign default, as in Aguiar and Gopinath (2006) or Arellano (2008), and show that this variation is consistent with multiple interest rate equilibria. Some of those equilibria correspond to the ones identified by Calvo (1988), where default is likely because rates are high, and rates are high because default is likely. The model is used to simulate equilibrium movements in sovereign bond spreads that resemble sovereign debt crises. It is also used to discuss lending policies similar to the ones announced by the European Central Bank in 2012.

We use the Ramsey and Mirrlees approaches to study how fiscal and trade policy should be set cooperatively when governments must raise revenues with distorting taxes. Free trade and unrestricted capital mobility are optimal. Efficient outcomes can be implemented with taxes only on final consumption goods and labor income. We study alternative tax systems, showing that uniform taxation of household asset returns, and not taxing corporate income yields efficient outcomes. Border adjustments exempting exports from and including imports in the tax base are desirable. Destination- and residence-based tax systems are desirable compared to origin- and source-based systems.

The interplay between competition and trust as efficiency-enhancing mechanisms in the private provision of money is studied. With commitment, trust is automatically achieved and competition ensures efficiency. Without commitment, competition plays no role. Trust does play a role but requires a bound on efficiency. Stationary inflation must be non-negative and, therefore, the Friedman rule cannot be achieved. The quality of money can be observed only after its purchasing capacity is realized. In this sense, money is an experience good.

In this article, we analyze the implications of price-setting restrictions for the conduct of cyclical fiscal and monetary policy. We consider standard monetary economies that differ in the price-setting restrictions imposed on the firms. We show that, independently of the degree or type of price stickiness, it is possible to implement the same efficient set of allocations and that each allocation in that set is implemented with policies that are also independent of the price stickiness. In this sense, environments with different price-setting restrictions are equivalent.

We revisit the question of how capital should be taxed. We allow for a rich set of tax instruments that consists of taxes widely used in practice, including consumption, dividend, capital, and labor income taxes. We restrict policies to respect promises that the government has made in the previous period regarding the current value of wealth. We show that capital should not be taxed if households have preferences that are standard in the macroeconomics literature. We show that Ramsey outcomes that must respect such promises are time consistent. We show that the presumption in the literature that capital should be taxed for some length of time arises because the tax system is restricted.