Trade Policy and the Emissions Content of Agricultural Trade with Keliang Xiao and William Ridley (UIUC),  In Progress
Agriculture's role in the generation of greenhouse gases (GHGs) has come under increasing scrutiny. Simultaneously, global agricultural production and trade continue to rise due to ever-growing demand and persistent reductions in trade barriers. We investigate the implications of agricultural trade liberalization for global farm-gate GHG emissions embodied in traded agricultural commodities. To do this, we employ a structural gravity estimation and simulation framework to quantify the counterfactual impacts of tariff preferences on global trade flows, and the embodied emissions content of these flows, for a selection of prominent agricultural commodities. We document that tariff preferences have led to a global increase in trade-embodied emissions of nitrous oxides (N2O) and methane (CH4), two major greenhouse gases, of 20.68 and 714.65 kilotons, respectively---a CO2-equivalent increase of 37.88 megatons equaling 120.46% of global farm-gate GHG emissions from agriculture. Our findings underscore the critical need to balance trade policy with climate and environmental considerations.

Choking on Smoke: How Wildfire Smoke Fuels Pollution Emissions in the U.S. Electricity Sector with Daniel Kaffine (CU Boulder),  In Progress
Over recent decades, wildfires in the United States have become more frequent and severe. At the same time, the electricity sector has seen a growing shift toward renewable energy sources like solar and wind, contributing to an overall decline in pollution emissions. These two trends raise an important question: does intensified wildfire smoke, by reducing the efficiency of renewable generation, drive up emissions through increased reliance on non-renewables? We address this by first testing whether wildfire smoke leads to higher emissions in the electricity sector, then examining whether short-term shifts from renewable to non-renewable sources are the primary driver, and finally analyzing how non-renewable generation adjusts within counties affected by smoke. Using daily precipitation as an instrument for wildfire-related PM2.5, we find that: (a) pollution emissions rise significantly on smoke days; (b) the shift from renewable to non-renewable generation partly explains the increase, but elevated electricity demand on smoke days also plays a key role; and (c) the response within non-renewables comes mainly from increased generation levels rather than changes in fuel mix or gains in efficiency/intensified abatement activities. These findings reveal overlooked environmental consequences of wildfire smoke and show how the U.S. electricity sector dynamically adjusts under such conditions.

When Regulation Travels: Supply Chain Disruptions and Environmental Spillovers under the Clean Air Act with Scott Holladay (U of Tennessee), Jay Hyun (U of Alberta) and Gueyon Kim (UCSC),  In Progress
We study how environmental regulation shapes firms’ supply chains and emissions. Our analysis rests on three key observations: (i) the Clean Air Act imposes geographically and temporally varying stringency, (ii) U.S. firms deeply embedded in supply chains are also concentrated in regulated regions, and (iii) inter-firm linkages transmit both direct and indirect regulatory exposures through business partners. Using a detailed U.S. establishment data combined with firm-to-firm linkage information, we distinguish between direct regulatory exposures faced by a firm's own establishments and indirect exposures originating from its suppliers and customers. We find that establishments facing regulatory shocks transmitted through their network counterparts sever ties with regulated partners and face barriers to forming new regulated relationships, with little evidence of substitution toward unregulated ones. While these network adjustments reveal how firms reorganize to mitigate regulatory shocks, they play only a modest role in explaining changes in environmental performance: establishments lower emissions in response to direct and supplier-side regulatory exposures but increase emissions when their customers are regulated---regardless of whether network adjustments are controlled for. The asymmetric responses are consistent with customers’ stronger bargaining power within core relationships, which enables them to shift compliance burdens upstream. Overall, the findings underscore the importance of accounting for indirect regulatory exposures when evaluating both supply chain adjustments and the environmental consequences of regulation.

When Trade Meets the Sky: How Global Value Chains Shape Industrial Air Pollution with William Ridley (UIUC),  Under Review
We study the joint roles of global value chain (GVC) positioning (the "distance" of an industry from its upstream inputs and downstream consumers) and trade competitiveness (the effective prices received by an industry for its exports or paid on its imports in terms of foreign exchange) in determining the intensity of industries' emissions of air pollution. Using data on country-by-industry emissions and GVC positions, we first document that industries' emission intensities are mediated by their distance in the value chain from primary factors versus final consumers, as well as their trade competitiveness. Second, we show that the improved import competitiveness but worsened export competitiveness arising from an appreciation of the domestic currency can lead to declines in emission intensities for industries operating in vertically longer production networks (i.e., value chains with a larger number of industry segments separating primary factors from final consumption). The main insights of our analysis underscore that international trade policies that (i) encourage the consolidation of GVC participants towards "core" positions or (ii) extended GVCs can complement international environmental policy efforts.

New Space Economy with Akhil Rao (Middleburry), Forthcoming,  Oxford Handbook Chapter
Do Competitive Markets Cleanup the US Electricity Sector?: Evidence from the Southwest Power Pool with Daniel Kaffine (CU Boulder),  The Energy Journal (2025)
Thirsty for Trade: How Globalization Shapes Virtual Water Trade with William Ridley (UIUC),  Environmental and Resource Economics (2025)
How Do Exchange Rates Affect the Environment? with William Ridley (UIUC),  Canadian Journal of Economics//Revue canadienne d'économique (2025)
Regional Heterogeneity in Environmental Quality: The Role of Firm Production Networks and Trade with Jacob Howard (MITRE) and William Ridley (UIUC),  Journal of the Association of Environmental and Resource Economists (2024)
Harmonizing Welfare and Externalities: Unraveling the Product Versus Process Standards Puzzle in Regulatory Policy with Difei Geng (UARK),  Economics Bulletin (2023)
Can the Federal Reserve Save the Environment? with Kyoung-Gon Kim (Dongguk Univ.),  Journal of Cleaner Production (2023)
 US Power Grid and Trade, with Daniel Kaffine and Sergey Nigai (CU Boulder)
 Wildlife Crossings and Accidents, with Hyunseok Jung and Tandem Young (UARK)