This paper develops a simple theory of capital controls as dynamic terms-of-trade manipulation. We study an infinite horizon endowment economy with two countries. One country chooses taxes on international capital flows in order to maximize the welfare of its representative agent, while the...

The Lerner Symmetry Theorem (Lerner, 1936) establishes the equivalence between import tariffs and export taxes in a simple neoclassical economy with two countries, two final goods, and no trade costs. In this paper we provide a number of generalizations and qualifications of this well-known...

Technological change, from the advent of robots to expanded trade opportunities, tends to create winners and losers. How should government policy respond? And how should the overall welfare impact of technological change on society be valued? We provide a general theory of optimal technology...

The theory of comparative advantage is at the core of neoclassical trade theory. Yet we know little about its implications for how nations should conduct their trade policy. For example, should import sectors with weaker comparative advantage be protected more? Conversely, should export sectors...

The empirical observation that “large firms tend to export, whereas small firms do not” has transformed the way economists think about the determinants of international trade. Yet, it has had surprisingly little impact about how economists think about trade policy. In this paper, we...

We present a theory of Keynesian supply shocks: supply shocks that trigger changes in aggregate demand larger than the shocks themselves. We argue that the economic shocks associated to the COVID-19 epidemic—shutdowns, layoffs, and firm exits—may have this feature. In one-sector economies...

What circumstances or policies leave sovereign borrowers at the mercy of self-fulfilling increases in interest rates? To answer this question, we study the dynamics of debt and interest rates in a model where default is driven by insolvency. Fiscal deficits and surpluses are subject to shocks...

To what degree should societies allow inequality to be inherited? What role should estate taxation play in shaping the intergenerational transmission of welfare? We explore these questions by modeling altruistically-linked individuals who experience privately observed taste or productivity...

I study monetary and fiscal policy in liquidity trap scenarios, where the zero bound on the nominal interest rate is binding. I work with a continuous-time version of the standard New Keynesian model. Without commitment, the economy suffers from deflation and depressed output. I show that,...

We provide explicit solutions for government spending multipliers during a liquidity trap and within a fixed exchange regime using standard closed and open-economy models. We confirm the potential for large multipliers during liquidity traps. For a currency union, we show that self-financed...