Air pollution disperses across political boundaries, yet many environmental policies regulate specific polluted locations. This paper studies how cross-boundary transport of fine particulate matter (PM2.5) changes the welfare effect and optimal design of pollutant control policy in China. Using particle trajectory data from atmospheric transport models, we construct bilateral pollutant-flow matrices that measure the transboundary air pollution in China. Three patterns emerge: (1) Transboundary pollution contributes heterogeneously to local PM2.5, accounting for less than 10% to over 50% of provincial concentrations; (2) Bilateral pollutant transport networks remain stable over time, enabling long-term policy coordination without frequent recalibration; and (3) Economically developed provinces in China receive more transboundary pollution yet achieve larger pollution reduction. We develop a dynamic spatial general equilibrium model that incorporates pollutant transport, trade, and migration. Using this model, we estimate that transboundary air pollution creates a 1% national welfare loss relative to a counterfactual where pollution remains local. We evaluate China's Air Pollution Prevention and Control Action Plan and compare it to alternative allocation rules. Reallocating abatement target to high-spillover upwind provinces based on marginal social welfare of emission tax improves aggregate welfare by 0.18% relative to the actual policy. The findings reveal welfare gains from accounting for spatial externalities in policy design.

Presentations: *PSE Environmental Economics Workshop, UEA North America Annual Meeting, LSE Economics of Energy and Environment Seminar, LSE Trade and Urban Seminar

This paper examines how trade shocks affect the gender employment gap in economies with large informal sectors. Exploiting regional exposure to Brazil's 1990s trade liberalization, I find that tariff reductions reduce female employment in both medium and long terms, while male employment remains stable and eventually rises, widening the gender gap. Decomposition reveals that women bear disproportionate job losses in the formal sector, while men absorb the shock by moving into informal work. Further analysis shows that occupational segregation and caregiving constraints prevent women from utilizing informal employment to buffer against trade shocks. The results highlight how informality interacts with gender-specific barriers to amplify inequality under trade liberalization.

This project examines how the China Initiative, a U.S. national security policy launched in 2018, reshaped the spatial distribution of Chinese-born researchers and skilled workers across firms and regions. Using online job postings, publication, and patent data, we analyze how heightened scrutiny prompted relocation across firms and regions, and reduced collaboration between U.S. and China-affiliated institutions. The project explores how geopolitical tensions and policy uncertainty reshape the geography of talent and innovation.