I am an Associate Professor of Economics at the University of Chicago Booth School of Business, a Faculty Research Fellow at the National Bureau of Economic Research, and a Research Fellow at the Centre for Economic Policy Research. My research agenda focuses on the spatial distribution of economic activities across neighborhoods, cities, and countries. I try to understand the substantial variation in the amount and nature of economic activity across space (September 2023 research statement). In 2022, my research was recognized by the Bhagwati Award and August-Lösch Prize.

In January 2025, I will join Columbia University as a tenured Associate Professor of Economics.

I have editorial duties at journals listed on my CV: REStat, JIE, and JUE.

jid2106@columbia.edu
(773) 834-5458

Chicago Booth, Room 380
5807 South Woodlawn Avenue
Chicago, IL 60637

NBER | Google Scholar | RePEc | GitHub

TradeDiversion.net | @TradeDiversion

Market Size and Trade in Medical Services

April 2024 (with Josh Gottlieb, Maya Lozinski, Pauline Mourot)
[Revisions requested at American Economic Review]

We uncover substantial interregional trade in medical services and investigate whether regional increasing returns explain it. In Medicare data, one-fifth of production involves a doctor treating a patient from another region. Larger regions produce greater quantity, quality, and variety of medical services, which they “export” to patients from elsewhere, especially smaller regions. We show that these patterns reflect scale economies: greater demand enables larger regions to improve quality, so they attract patients from elsewhere. Despite concerns about rural access, larger regions have higher marginal returns to spending. We study counterfactual policies that would lower travel costs rather than relocating production.

Media mentions: Washington Post, The Center Square, Chicago Booth Review, For All

Spatial Economics for Granular Settings

September 2023 (with Felix Tintelnot)
[More revisions requested at Econometrica]

We examine the application of quantitative spatial models to the growing body of fine spatial data used to study local economic outcomes. In granular settings in which people choose from a large set of potential residence-workplace pairs, observed outcomes in part reflect idiosyncratic choices. Using both Monte Carlo simulations and event studies of neighborhood employment booms, we demonstrate that calibration procedures that equate observed shares and modeled probabilities perform very poorly in these high-dimensional settings. Parsimonious specifications of spatial linkages deliver better counterfactual predictions. To quantify the uncertainty about counterfactual outcomes induced by the idiosyncratic component of individuals' decisions, we introduce a quantitative spatial model with a finite number of individuals. Applying this model to Amazon's proposed second headquarters in New York City reveals that its predicted consequences for most neighborhoods vary substantially across realizations of the individual idiosyncrasies.

Spatial Correlation, Trade, and Inequality: Evidence from the Global Climate

July 2023 (with Kyle Meng and Solomon Hsiang)
[Revisions requested at Review of Economics and Statistics]

Global phenomena, such as climate change, often have local impacts that are spatially correlated. We show that greater spatial correlation of productivities can increase international inequality by increasing the correlation between a country's productivity and its gains from trade. We confirm this prediction using a half-century of exogenous variation in the spatial correlation of agricultural productivities induced by a global climatic phenomenon. We introduce this general-equilibrium effect into projections of climate-change impacts that typically omit spatial linkages and therefore do not account for the global scope of climate change. We project greater international inequality, with higher welfare losses across Africa.

Internal Trade Barriers in India

September 2024 (with Prabhat Barnwal, Daniil Iurchenko, Pravin Krishna, Eva Van Leemput)
PDF

We study barriers to intranational trade in India, which has extensive roads but an inefficient transportation and logistics sector. The Goods and Services Tax introduced in 2017 imposed nationwide tax rates and eliminated the need for tax-collection checkposts at state borders. We quantify the impact of this checkpost reform using high-frequency Global Positioning System records, trucking logs, and a survey of truck drivers. The reform sped up border crossings substantially: average duration declined more than one-third. Eastern states, which had slower checkposts before the reform, improved the most. Household expenditures rose in districts where the reform improved market access, suggesting substantial returns to reducing interstate trucking costs.

Demographic Preferences and Income Segregation

September 2024 (with Victor Couture, Allison Green, Jessie Handbury)
PDF

We investigate whether demographic preferences explain income segregation in shared spaces. To distinguish preferences over demographic composition from preferences over other venue characteristics, we study venue choices within business chains. We find two notable regularities: racial homophily does not vary by income, and preferences for high-income co-patrons are similar across racial groups. These demographic preferences are economically large, explain much of the cross-group variation in exposure to high-income co-patrons, and correlate with movers' neighborhood choices.

Measuring movement and social contact with smartphone data: a real-time application to COVID-19

Journal of Urban Economics, JUE Insight, 2022, Volume 127 (with Victor Couture, Allison Green, Jessie Handbury, Kevin Williams)

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. These data cover broad sections of the US population and exhibit pre-pandemic patterns similar to conventional survey data. We develop and make publicly available a location exposure index that summarizes county-to-county movements and a device exposure index that quantifies social contact within venues. We also investigate the reliability of smartphone movement data during the pandemic.

How Many Jobs Can be Done at Home?

Journal of Public Economics, 2020, Volume 189 (with Brent Neiman)

We classify the feasibility of working at home for all occupations. We find that 37 percent of jobs in the United States can be performed entirely at home, with significant variation across cities and industries. Applying our occupational classification to 85 other countries reveals that lower-income economies have a lower share of jobs that can be done at home.

Media mentions: WSJ, Brookings, Politico, Vox, Journalist's Resource, International Business Times, Daily Mail, Business Insider, Quartz, WSJ, Economist, Vice, Reason, FT, MarketWatch, The Hill, BI, WSJ, NYT, AEI, NYT, Reuters, BI, NYT, Reuters, NYT, Economist, BBC, LA Times, FT, 2023 Economic Report of the President

The Comparative Advantage of Cities

Journal of International Economics, 2020, Volume 123 (with Don Davis)
Winner of 2022 Bhagwati Award

What determines the distributions of skills, occupations, and industries across cities? We develop a theory that incorporates a system of cities, their internal urban structures, and a high-dimensional theory of factor-driven comparative advantage. It predicts that larger cities will be skill-abundant and specialize in skill-intensive activities according to the monotone likelihood ratio property. Data on US cities, education groups, occupations, and industries are consistent with our theory's predictions.

Cities, Lights, and Skills in Developing Economies

Journal of Urban Economics, 2021, Volume 125 (with Antonio Miscio and Don Davis)

We construct metropolitan areas for Brazil, China, and India by aggregating finer geographic units on the basis of contiguous areas of light in nighttime satellite images. In China and India, lights-based metropolitan populations follow a power law, while administrative units do not. Examining variation in relative quantities and prices of skill across these metropolitan areas, we conclude that agglomeration is skill-biased in Brazil, China, and India.

How Segregated is Urban Consumption?

Journal of Political Economy, 2019, 127(4): 1684-1738 (with Don Davis, Joan Monras, and Eduardo Morales)

We measure ethnic and racial segregation in urban consumption using Yelp reviews of NYC restaurants. Spatial frictions cause consumption segregation to partly reflect residential segregation. Social frictions also matter: individuals are less likely to visit restaurants in neighborhoods demographically different from their own. Nonetheless, restaurant consumption in New York City is only about half as segregated as residences. Consumption segregation owes more to social than spatial frictions.

A Spatial Knowledge Economy

American Economic Review, 2019, 109 (1): 153-70 (with Don Davis)

We develop the first system-of-cities model with costly idea exchange as the agglomeration force. The model replicates a broad set of established facts about the cross section of cities. It provides the first spatial equilibrium theory of why skill premia are higher in larger cities and how variation in these premia emerges from symmetric fundamentals.

The Determinants of Quality Specialization

Review of Economic Studies, 2017, 84(4), p.1551–1582

Why do high-income countries export high-quality goods: home demand or factor abundance? I develop a model nesting both hypotheses and employ microdata on US manufacturing plants' shipments and factor inputs to quantify the two mechanisms' roles in quality specialization across US cities. Home-market demand explains as much of the relationship between income and quality as differences in factor usage.

Telemigration and Development: On the Offshorability of Teleworkable Jobs

chapter in Robots and AI: A New Economic Era, 2022 (with Richard Baldwin)

How many newly remote jobs will go overseas? We offer a rough quantification. Telemigration seems unlikely to be transformative. Remote work is English- & soft-skill-intensive. Baseline services exports are small, and the standard gravity model restricts modest changes to have modest impacts. We propose a simple model of telemigration in which small changes can have large consequences.

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MBA

Managing the Firm in the Global Economy

This course studies international economics from the perspective of the firm. Its objective is to equip students with analytical tools to understand the organizational, financial, and legal issues facing firms doing business across borders.

PhD