This paper develops an elementary theory of global supply chains. We consider a world economy with an arbitrary number of countries, one factor of production, a continuum of intermediate goods, and one final good. Production of the final good is sequential and subject to mistakes. In the unique...

This paper proposes a simple theory of international trade with endogenous productivity differences across countries. The core of our analysis lies in the determinants of the division of labor. We consider a world economy comprising two large countries, with a continuum of goods and one factor...

The primary motivation behind quantitative modeling in international trade and many other fields is to shed light on the economic consequences of policy changes. To help assess and potentially strengthen the credibility of such quantitative predictions we introduce an IV-based goodness-of-fit...

The textbook case for industrial policy is well understood. If some sectors are subject to external economies of scale, whereas others are not, a government should subsidize the first group of sectors at the expense of the second. The empirical relevance of this argument, however, remains...

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...

About 8 cents out of every dollar spent in the United States is spent on imports. What if, because of a wall or some other extreme policy intervention, imports were to remain on the other side of the US border? How much would US consumers be willing to pay to prevent this hypothetical policy...

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...

In this paper we develop a new approach to measuring the gains from economic integration based on a generalization of the Ricardian model in which heterogeneous factors of production are allocated to multiple sectors in multiple local markets based on comparative advantage. We implement this...