We provide measures of ethnic and racial segregation in urban consumption. Using Yelp reviews, we estimate how spatial and social frictions influence restaurant visits within New York City. Transit time plays a first-order role in consumption choices, so consumption segregation partly reflects...

A growing literature suggests that high-income countries export high-quality goods. Two hypotheses may explain such specialization, with different implications for welfare, inequality, and trade policy. Fajgelbaum, Grossman, and Helpman (2011) formalize the Linder hypothesis that home demand...

In developed economies, agglomeration is skill-biased: larger cities are skill-abundant and exhibit higher skilled wage premia. This paper characterizes the spatial distributions of skills in Brazil, China, and India. To facilitate comparisons with developed-economy findings, we construct...

This paper shows that greater global spatial correlation of productivities can increase cross-country welfare dispersion by increasing the correlation between a country's productivity and its gains from trade. We causally validate this prediction using a global climatic phenomenon as a natural...

Leading empiricists and theorists of cities have recently argued that the generation and exchange of ideas must play a more central role in the analysis of cities. This paper develops the first system of cities model with costly idea exchange as the agglomeration force. Our model replicates a...

Tracking human activity in real time and at fine spatial scale is particularly valuable during episodes such as the COVID-19 pandemic. In this paper, we discuss the suitability of smartphone data for quantifying movement and social contact. We show that these data cover broad sections of the US...

Evaluating the economic impact of "social distancing" measures taken to arrest the spread of COVID-19 raises a fundamental question about the modern economy: how many jobs can be performed at home? We classify the feasibility of working at home for all occupations and merge this classification...

What determines the distributions of skills, occupations, and industries across cities? We develop a theory to jointly address these fundamental questions about the spatial organization of economies. Our model incorporates a system of cities, their internal urban structures, and a...

We develop a quantifiable multi-country sourcing model in which firms self-select into importing based on their productivity and country-specific variables. In contrast to canonical export models where firm profits are additively separable across destination markets, global sourcing decisions...

We use Belgian data with information on domestic firm-to-firm sales and foreign trade transactions to study how international trade affects firms' unit cost and the consumer's real wage. We show theoretically that the gains from trade depend on domestic firm-to-firm linkages. Furthermore, we...