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...

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...

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...

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...