Domestic Trade Shocks from E-Commerce Expansion: Evidence from Amazon’s Distribution Facilities

[paper link] [slides] July 2025

• This paper studies Amazon's distribution facility expansion as a domestic trade shock, using detailed data on Amazon facilities, products, and sellers. I develop a spatial trade model with endogenous online entry and consumer search. Guided by the model, I find that facility entry raises local online seller activity and sales, consistent with reductions in shipping frictions and increases in interregional trade. Quantitative results show gains in state-level welfare driven by price effects, but widening regional disparities in real income. 

• Subsumes an earlier working paper "E-commerce and Regional Inequality: A Trade Framework and Evidence from Amazon’s Expansion"​​​

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Occupational Skill Mixing Under Breakthrough GPTs

 [paper link] [slides] May 2025

• Leveraging a near-universe of U.S. online job postings alongside task descriptors from 2005 to 2024, this paper documents a substantial increase in skill mixing—the integration of skills previously specific to other occupations. This trend is especially pronounced in lower-skill occupations, and is shaped by mixed skills that originate in high-skill jobs and are biased toward non-routine computer and analytical skills. This rise is further corroborated when measured by an intensive margin of skill balancing. To explain these patterns, I examine the impact of breakthrough general‑purpose technologies (GPTs)—innovations that are simultaneously highly novel and broadly applicable—identified using patent data and mapped to occupational usage. Event-study estimates show that exposure to a breakthrough GPT raises the number of mixed skills by about 4 percent on impact—an effect that persists—and increases wages and employment by 2 and 8 percent within six years, with effects concentrated in low-skill occupations. A calibrated multidimensional matching model with endogenous occupation design attributes the breakthrough GPT driven rise in mixing primarily to greater complementarity among skills and more convex occupational costs, which also contribute to aggregate occupation wage gaps and nearly half of the changing employment ratios.