Job Market Paper
Specialization By Design: The Unequal Geographic Effects of Modular Product Design
I show that modular design – a revolution in how firms organize innovation – concentrates industrial production in large countries. Modular products follow common rules called design platforms, and thus can share inputs while remaining customized for local needs. Combining six new datasets on global automotive design and trade, event studies of product redesigns, and a model with scale economies in shared input production, I show that design platforms reshape global trade in two phases. First, platform-sharing across destinations increases input trade, as countries specialize in preferred product types rather than in local products. For instance, poor countries export engines for affordable cars. Second, platform-sharing across product types creates winner-take-all supply chains in which the largest and most-productive countries produce all inputs. Both effects occur because modularity increases the scope of countries’ market size advantages, concentrating input production in large markets for each platform rather than each product. As a result, modular design has unequal country-level implications: in model counterfactuals, adoption to date shifts production from smaller countries to Germany, Japan and South Korea, and universal platforms (expected by 2030 for EVs) double American and Chinese shares while reducing production by over 80% in a majority of countries.
Publications
Unreliable Firms: Evidence from Rwanda
with Brandon Tan (IMF)
Journal of Development Economics (2025)
This paper develops a new measure of reliability — whether firms execute transactions on-schedule — for the universe of Rwandan formal firms using transaction timing data and describe the characteristics of reliable firms. Reliable firms have larger interfirm sales, export more, supply exporters and multinationals, and transact with other reliable firms. Reliable firms are less sensitive to supply chain disruptions. Supplying an MNC increases seller reliability even when servicing non-MNC buyers.
Working Papers
Supply Chain Resilience via Partial Integration
How do firms adapt to ensure supply chain resilience? The typical answer, vertical integration, is limited in practice by its high costs and inflexibility. This paper introduces partial integration, defined as targeted buyer interventions across firm boundaries, as an effective alternative. Using novel daily timeline data from Indian manufacturing supply chains, we show that supplier underinvestment in key inputs, stemming from working capital constraints and noncontractibilities in input use, is the primary driver of disruptions in these supply chains. To reduce the incidence of disruptions, buyers exert control over supplier processes—through in-person monitoring, contingent contracts, and direct sourcing of raw materials—rather than merely advancing cash. This buyer involvement escalates as disruption risk increases: an unanticipated input cost shock leads to direct buyer control of inputs for the most constrained suppliers. We develop a three-stage model that rationalizes these strategies. The model clarifies that buyers control input decisions to prevent resource diversion due to noncontractibility, while allowing suppliers to retain control of production in order to preserve output market incentives. It also predicts that relational buyers with low monitoring and sourcing costs enjoy a comparative advantage in fostering resilient trade with poor regions.
Who Picks Winners? Evidence From Industrial Policy Application Cycles
Draft coming soon
In many settings, bureaucrats are formally responsible for industrial policy, but politicians retain de facto power to disburse limited funds. Using confidential data on the universe of industrial subsidy applications in a large Indian state, we show that bureaucrats approve over 90% of applications, yet fewer than 30% of approved subsidies are ultimately paid, with an average delay of 3.5 years. Firm bargaining power (proxied by size and local headquarters) predicts earlier payouts, and payments often prioritize a specific high-profile plants or industrial cluster. Moreover, firms facing larger negative demand shocks—identified via a shift-share design—are more likely to receive payments for previously approved investments. These results highlight the challenge of insulating industrial policy from political influence, as constrained funds and opaque decision-making enable favoritism long after investments have been made.
Work in Progress
The Origins of Productivity Growth in Modern Manufacturing: Evaluating the P&G Integrated Work System
with David Atkin (MIT), Amit Khandelwal (Yale), and John van Reenen (LSE)
This paper examines the productivity effects of reorganizing workers for automated production environments. Specifically, we evaluate the staggered rollout of a multinational manufacturer's internal production system across machines within several later-adopting manufacturers. The intervention, which was implemented by an elite professional services firm, consists of (i) giving each production worker overall responsibility for a single machine, (ii) requiring workers to complete proactive cleaning and regular maintenance alongside machine operation, and (iii) soliciting worker input on production issues through structured daily line-level meetings. The treatment reduces unplanned downtime by 50%, largely through reductions in short unplanned stops of under 5 minutes in duration. To achieve these gains, workers increase the precision of unique stop reasons tracked during production, and work more days in non-production tasks. The intervention leads to a 25% increase in plant-wide productivity, in part because machine-level gains spill over to (i.e. reduce stops in) other production stages within each plant.
A bank on every corner? Informal supply chain credit amid information frictions
with Daniel Ehrlich (UChicago)
Fieldwork completed November 2025
Supply chains in poor countries are underpinned by informal supply chain credit from suppliers to retailers, and from retailers to customers. How do sellers informally enforce trade credit payments, what frictions constrain the provision and repayment of supply chain credit, how do they shape firm size and scope, and what government interventions could address these frictions? By combining a field experiment with novel transaction-level supply chain credit data from an Indian bookkeeping app, we document that 1) trade credit defaults are common, which increases de facto trade costs, 2) firms restrict supply chain credit to socially and geographically proximate networks, 3) firms learn customer creditworthiness over time, 4) public information on buyer nonpayment is underprovided and predictive of future repayment, and 5) in event studies, providing public default information through the app improves trade credit enforcement in existing (in-default) relationships. Finally, by building a model in which firms grow through new credit relationships, we study how a counterfactual de-bundling of trade and credit through the introduction of credit cards affects the size and number of retail and wholesale firms.
The spatial reach of family business: evidence from India
with Sukrit Puri (London Business School) and Shivram Viswanathan (Harvard)
Other Work
Does Social Distancing Matter?
with Michael Greenstone (UChicago)
COVID Economics (2020)
This paper develops and implements a method to monetize the impact of moderate social distancing on deaths from COVID-19. Using the Ferguson et al. (2020) simulation model of COVID-19's spread and mortality impacts in the United States, we project that 3-4 months of moderate distancing beginning in late March 2020 would save 1.7 million lives by October 1. Of the lives saved, 630,000 are due to avoided overwhelming of hospital intensive care units. Using the projected age-specific reductions in death and age-varying estimates of the United States Government's value of a statistical life, we find that the mortality benefits of social distancing are about $8 trillion or $60,000 per US household. Roughly 90% of the monetized benefits are projected to accrue to people age 50 or older. Overall, the analysis suggests that social distancing initiatives and policies in response to the COVID-19 epidemic have substantial economic benefits.
Media coverage: Wall Street Journal, Washington Post, The Economist, Vox