I study the aggregate effects of labour market frictions in a small open economy where firms grow slowly and make fixed export investments. The model features interactions between dynamic investments in exporting and search frictions with job-to-job mobility. A calibration to Argentina’s economy matching data on firm growth, worker transitions between firms, and export dynamics suggests that the real income gains from lowering frictions in job-to-job transitions are about seven times larger than comparable reductions in frictions from unemployment. Barriers to worker mobility across firms matter for the real income gains of trade-cost reductions.

We develop a framework for studying trade in vertically and horizontally differentiated products. In our model, consumers with heterogeneous incomes and tastes purchase a homogeneous good as well as making a discrete choice of quality and variety of a differentiated product. The distribution of preferences in the population generates a nested logit demand structure. These demands are such that the fraction of consumers who buy a higher-quality product rises with income. We use the model to study the pattern of trade between countries that differ in size and income distributions but are otherwise identical. Trade―which is driven primarily by demand factors―derives from "home market effects" in the presence of transport costs. The model helps to explain why richer countries export higher-quality goods. It provides a tractable tool for studying the welfare consequences of trade, transport costs, and trade policy for different income groups in an economy.

We study optimal spatial policies in a quantitative trade and geography framework with spillovers and spatial sorting of heterogeneous workers. We characterize the spatial transfers that must hold in efficient allocations, as well as labor subsidies that can implement them. There exists scope for welfare-enhancing spatial policies even when spillovers are common across locations. Using data on U.S. cities and existing estimates of the spillover elasticities, we find that the U.S. economy would benefit from a reallocation of workers to currently low-wage cities. The optimal allocation features a greater share of high-skill workers in smaller cities relative to the observed allocation. Inefficient sorting may lead to substantial welfare costs.

Individuals that consume different baskets of goods are differentially affected by relative price changes caused by international trade. We develop a methodology to measure the unequal gains from trade across consumers within countries. The approach requires data on aggregate expenditures and parameters estimated from a nonhomothetic gravity equation. We find that trade typically favors the poor, who concentrate spending in more traded sectors.

We provide new theory and evidence on the role of external and internal integration in structural transformation and economic development, using Argentina’s integration into the world economy in the late nineteenth century. Our theoretical model provides microfoundations for a spatial Balassa-Samuelson effect, in which locations closer to world markets have higher population densities, urban population shares, relative prices of nontraded goods, and land prices relative to wages, as well as specializing in traded goods that are transport-cost sensitive. We estimate the model’s parameters, provide evidence in support of this spatial Balassa-Samuelson mechanism, and find substantial effects of both external and internal integration on economic development.

We study state taxes as a potential source of spatial misallocation in the U.S.. We build a spatial general equilibrium framework that incorporates salient features of the U.S. state tax system, and use changes in state tax rates between 1980 and 2010 to estimate the model parameters that determine how worker and firm location respond to changes in state taxes. We find that heterogeneity in state tax rates leads to aggregate welfare losses. In terms of consumption equivalent units, harmonizing state taxes increases worker welfare by 0.6% if government spending is held constant, and by 1.2% if government spending responds endogenously. Harmonization of state taxes within Census regions achieves most of these gains. We also use our model to study the general equilibrium effects of recently implemented and proposed tax reforms.

We develop a theory of endogenous uncertainty and business cycles in which short-lived shocks can generate long-lasting recessions. In the model, higher uncertainty about fundamentals discourages investment. Since agents learn from the actions of others, information flows slowly in times of low activity and uncertainty remains high, further discouraging investment. The economy displays uncertainty traps: self-reinforcing episodes of high uncertainty and low activity. Although the economy recovers quickly after small shocks, large temporary shocks may have long-lasting effects on the level of activity. The economy is subject to an information externality but uncertainty traps may remain in the efficient allocation. Embedding the mechanism in a standard business cycle framework, we find that endogenous uncertainty increases the persistence of large recessions and improves the performance of the model in accounting for the Great Recession.

After decades of supporting free trade, in 2018 the United States raised import tariffs and major trade partners retaliated. We analyze the short-run impact of this return to protectionism on the U.S. economy. Import and retaliatory tariffs caused large declines in imports and exports. Prices of imports targeted by tariffs did not fall, implying complete pass-through of tariffs to duty-inclusive prices. The resulting losses to U.S. consumers and firms that buy imports was $51 billion, or 0.27% of GDP. We embed the estimated trade elasticities in a general-equilibrium model of the U.S. economy. After accounting for tariff revenue and gains to domestic producers, the aggregate real income loss was $7.2 billion, or 0.04% of GDP. Import tariffs favored sectors concentrated in politically competitive counties, and the model implies that tradeable-sector workers in heavily Republican counties were the most negatively affected due to the retaliatory tariffs. JEL Code: F1.