Research

Working Paper

How Far Does a Climate Shock Travel? Effect of the Panama Canal Disruption on US West Coast Maritime Traffic and Air Pollution [Job Market Paper] 

Previously titled "Navigating the Ripple Effect: Unveiling the Hidden Currents of El Niño, the Panama Canal, and US West Coast Ports"

• Climate-induced disruptions in global trade routes have significant, far-reaching economic and environmental consequences. This study establishes the causal chain through which a climate shock at a critical chokepoint propagates through the global maritime network to degrade air quality in distant locations. Leveraging the 2023 El Niño-induced drought at the Panama Canal as a natural experiment within a chained 2SLS framework, I demonstrate that the disruption did not simply redistribute traffic flow, but propagated as a congestion spillover. Especially at US West Coast ports, the arrival of affected vessels collided with capacity ceilings, causing a significant surge in vessel waiting time rather than throughput. This accumulation of logistical buildup, in turn, led to a severe degradation of local air quality. The findings reveal notable heterogeneity in this effect: while cargo vessels polluted through congestion queues, tankers exerted a disproportionately larger marginal impact, increasing daily particulate matter (PM1) concentrations by up to 43.7%, driven by their high emissions intensity. My results provide a clear illustration of how localized climatic shocks create significant environmental externalities in distant regions, highlighting a novel and quantifiable mechanism of network-transmitted vulnerability.

Clearing the Air: The Complex Relationship Between Truck Emissions, NOₓ Reductions, and Ozone Formation in Bogotá

• We examine the causal impact of heavy-duty truck activity on urban air quality in Bogotá, Colombia, leveraging the 2016 truck riot as a natural experiment. Using high-frequency monitor data, the analysis finds that the disruption led to a statistically significant 30.2% reduction in daily average nitrogen oxides (NOx) concentrations. However, this reduction was accompanied by a 48.4% increase in ground-level ozone (O3), while fine particulate matter (PM2.5) levels remained statistically unchanged. An event study model further captures the temporal dynamics, showing an immediate divergence in pollutants that partially attenuated in later weeks, consistent with behavioral adaptations by other road users. We validate the intensity and timing of this supply-side shock using wholesale agricultural data, which reveals a structural break in food inflows and a distinct "V-shaped" recovery that temporally aligns with the observed air quality anomalies . These inverse outcomes for NOx and O3 provide compelling empirical evidence that Bogotá operated under a VOC-limited regime.  Consequently, policies focusing solely on reducing truck-related NOx emissions may be insufficient or counterproductive for controlling O3 pollution, underscoring the necessity for integrated management strategies targeting both NOx and VOCs.

China's Green Paradox: Electric Vehicle Dreams versus Coal Realities

• This study examines China's ambitious transition to electric vehicles (EVs) in relation to the Environmental Kuznets Curve (EKC) hypothesis, assessing its efficacy in reducing emissions given the nation’s energy infrastructure. Analyzing longitudinal data from 1960 to 2023, the research integrates a well-to-wheels emissions perspective with macroeconomic developments, technological innovations, and shifts in energy composition. Results show that China's coal-intensive electricity grid significantly undermines the short-term environmental advantages of EV adoption. However, over the long term, EV adoption demonstrates a modest yet statistically significant reduction in CO2, NOx, and GHG emissions, especially as natural gas and renewables become more integrated into the power grid.

Locked Out: Land Use Transitions and Demographics Dynamics

• Upzoning is increasingly cited as a supply-side instrument to combat the housing affordability crisis. However, some are concerned that upzoning is a part of a thinly veiled agenda for gentrification (Rodríguez-Pose and Storper, 2020). This paper investigates this tension in Southern California using novel longitudinal zoning data. We first employ emerging hotspot analysis to demonstrate the spatio-temporal trend of residential upzoning in Southern California over the last decade, finding that they cluster near popular migration destinations. We then use fixed-effects models and an instrumental variable approach to quantify the impacts of upzoning on populations. Our results show that upzoning did not increase the total population. Instead, cities with more upzoning experienced significant increases in young college graduates and decreases in the non-white population. These demographic shifts coincided with the development of new multi-family housing. As such, upzoning has not increased affordable housing supply, but has instead accommodated local gentrification trends.

Work in Progress

"Bureaucratic Professionalism and Sustainable Development: A Cross-National Analysis"

"Temporary Shipping Disruptions and Persistent Reconfiguration of Global Trade and  Shipping Networks"

"Effects of Phasing Out Nuclear Power: Evidence from South Korea"

"Health Implications of Maritime Transportation and Port Congestion at the Gulf Coast"

Publication

Lee, P. S. & Lee, C. M. (2022), “Are South Korean College Students Benefitting from Digital Learning,” International Journal of Human-Computer Interaction.

Lee, P. S. (2015), “Bayesian Model to Minimize the Loss from Loan Default,” BS Thesis, Duke University.