Zhihao Han (韩志豪)

Working papers:

• The Road to Cleaner Transit: Shaping Preferences for Electric Buses through Household Education (with Alberto Salvo, Timothy Wong, and Wai Yan Leong) Job Market Paper

Abstract: A major step towards decarbonizing public transport involves electrifying the urban bus fleets that currently run on diesel. We implemented an education campaign with 1200 households over four months, repeatedly highlighting the co-benefits of investing in cleaner technology while tracking use of public transport. Education covered the private benefits of electric buses such as reduced noise and fumes, along with social benefits like improved neighborhood air quality and climate mitigation. Our intervention significantly enhanced households’ awareness of bus engine types and perceived advantages of electric buses. Hypothetical choice experiments indicate that education raises WTP for electric buses by ten US cents per trip. The shift in preferences is observed in real behavior, with transit payments showing a sustained rise in electric bus ridership among treated households, particularly the majority who do not own cars and residents nearby bus lines served by electric buses. However, heterogeneity analysis reveals that stated preference shifts for certain groups, such as young participants and car owners did not consistently translate into real-world behavior change, highlighting the intention-action gap. Overall, our findings suggest that repeated exposure to relatively cheap educational campaigns can effectively shape environmental preferences and widen support for environmental protection.

Presentations:  18th Joint Economics Symposium of Six Leading EastAsian Universities, NUS International Behavioural Public Policy Workshop (IBPPW), Sustainability Forum with Fudan and Korea University, Bridging Transportation Researchers (BTR) Conference, Sustainable Asia Conference, NUS Applied Economics Student Workshop, Singapore Land Transport Authority (LTA) Meeting, NUS Graduate Research Seminar

• The Challenge of Regulating Dirty New Industries: Evidence from Cryptocurrency Mining (with Siddharth George and Alberto Salvo)

Abstract: We evaluate two major efforts to decarbonise energy-intensive cryptocurrency mining.  First, we analyse the impacts of China's cryptomining ban using a difference-in-differences design.  The ban decreased electricity consumption in mining-intensive Chinese provinces by 5% and shifted electricity generation towards non-fossil sources.  While effective within China, the ban induced a global relocation of mining activity, with China exporting and the US importing more cryptomining equipment.  This relocation increased electricity consumption and fossil generation in mining-heavy US states, diluting the global impact of China's ban by 30-40%.  Second, we examine Ethereum's transition to Proof-of-Stake, a cleaner production technology.  Using a regression discontinuity design, we find that Ethereum's switch reduced US electricity consumption.  However, miners redeployed their equipment to mine other cryptocurrencies, offsetting the impact of Ethereum's transition by 30\%.  Our findings illustrate the difficulty of decarbonising energy-intensive industries with mobile, redeployable production factors.

Presentations: Applied Economics Workshop (AEW), Columbia University Interdisciplinary Ph.D. Workshop in Sustainable Development (IPWSD), NUS Environmental Economics Workshop, NUS Applied Micro SIG Brownbag Workshop, Joint NUS-ES workshop, NUS Graduate Research Seminar

Selected Work in Progress:

• NIMBY: Noise from the Build-Out of Clean Infrastructure and the Housing Market (with Yaming Lei)

Brief summary (subject to revision): This paper quantifies the noise disamenities from large-scale infrastructure construction inferred through the housing market. We focus on the construction of high-speed rail linking London to Birmingham in UK. While the final product can be viewed as clean technology, building out such mega-infrastructure is dirty and noisy. The protracted construction timeline provides a unique quasi-experimental setting to evaluate how the construction noise exposure affects the local communities. We build a novel dataset combining high-frequency hourly noise readings, granular construction inventories, and nationwide rental and sales listings as well as housing transaction records. The identification strategy exploits quasi-experimental variation in the timing of noisy construction activities, combined with cross-sectional variation in the intensity of planned construction near properties. We find that a one-decibel increase in daily average noise exposure during the three months prior to listing reduces rental listing prices by 0.6 to 0.9 percentage points and decreases the probability that a property is successfully rented. We find similar patterns on the housing transaction market, where pre-listing noise exposure reduces asking prices, and the listing-to-transaction noise exposure increases the wedge between asking and sold price, lowers the probability and lengthens the time to secure a buyer. Our results provide the first estimates on the elasticity of rents and housing prices with respect to heavy noisy construction, which is important for policymakers who often seek to compensate local communities including homeowners in an attempt to increase public support and spread the social cost of construction across the taxpayer base.

• Classification of Death Causes and Estimates of the Mortality Effects of Air Pollution (with Alberto Salvo and Nelson Gouveia)

Brief summary (subject to revision): This paper examines the impact of air pollution on mortality rates using the universe of death records in the City of São Paulo. We find a smaller elasticity of mortality with respect to air pollution compared to the previous literature. Our results reveal sensitivity to the classification standards used for cause-specific mortality and demonstrate selection bias in studies that rely exclusively on public hospital data. Heterogeneity analyses reveal larger pollution effects among non-Hispanic whites and individuals with higher educational attainment. These findings contrast sharply with evidence from the United States, where disadvantaged groups are typically more vulnerable to pollution exposure. Our results contribute novel evidence from a developing-country context and underscore how the definition of cause of death and coverage of death records can fundamentally affect the estimated relationship between air pollution exposure and health outcomes.

• Contingent Valuation on Willingness-to-Pay for Electric Buses

• Smart Road Pricing (with Alberto Salvo, Binglin Wang, Kwok-Hao Lee, and Esther, Tay Wen Hsin)

Teaching:

• Teaching Assistant, Econ 3303, Econometrics I (Undergraduate), with Dr. Kelvin Seah Kah Cheng and Dr. VU Thanh Hai

• Teaching Assistant, Econ 6103, Econometric Modelling and Applications II (Graduate), with Prof. Seo Juwon

• Lecturer, PhD Math Camp

Miscellneous:

• Top 10 finalist in VSAE Econometrics Game, Team Leader of National University of Singapore

• Dog lovers