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)

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 or 10% of the average bus fare. The shift in preferences is observed in real behavior, with transit payments showing a persistent rise in electric bus ridership among treated households, particularly the majority who do not own cars and residents who live near bus lines served by electric buses. However, heterogeneity analysis reveals that preference shifts for certain groups, such as car owners, did not consistently translate into behavior change, highlighting the difficulty of substituting across travel modes. Overall, our findings suggest that repeated exposure to relatively cheap educational campaigns can effectively shape environmental preferences and widen support for environmental protection.

Presentations:  International Conference on Empirical Economics (ICEE) at PSU-Altoona, 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: Computation-intensive digital industries are rapidly expanding, yet there is little evidence on how to decarbonise them.  We examine two major efforts to decarbonise cryptocurrency mining.  First, we evaluate China's cryptomining ban using a difference-in-differences design.  The ban reduced electricity consumption and fossil-fuel generation in mining provinces, lowering China's total electricity use by 0.59\%.  In response, mining activity relocated: China exported more cryptomining equipment, which flowed to established US mining hubs.  Electricity consumption increased in US mining states, powered by increased fossil generation, especially from old coal plants. This relocation attenuated the global impact of China's ban by one-third.  Second, we examine Ethereum's transition to Proof-of-Stake, a cleaner production technology, using a regression discontinuity design.  Ethereum's switch reduced US electricity consumption, but miners redeployed their equipment to mine substitute cryptocurrencies, diluting its impact.  Our findings illustrate the difficulty of regulating emerging industries like AI that use mobile, multi-purpose 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

• NIMBY: Build-Out of High Speed Rail and the Housing Market (with Yaming Lei)

Abstract: Provision of public goods often entails a tradeoff between broad social benefits and concentrated local costs, which can trigger strong opposition from nearby communities. We study this form of NIMBYism by quantifying the construction-phase disamenities generated by the High Speed 2 railway project in the United Kingdom. We first estimate how the project’s statutory authorization is capitalized into local housing markets. Transaction prices exhibit a U-shaped capitalization gradient with distance from the route, falling by up to 5% in the 3 to 6 km band, while rental prices respond more modestly. Construction disamenities account for about 72% of the gross transaction-price capitalization and 60% of the rental capitalization, with anticipated operational benefits and compensation partially offsetting these losses. We then focus on construction noise as a key channel through which these disamenities are capitalized. Combining hourly readings from a dense noise-monitoring network with daily construction logs, we show that HS2 construction raises ambient noise by 1.76 decibels. Using the shift-share instrumental variable design within a hedonic pricing framework, we estimate that a one-decibel increase in daytime construction noise reduces transaction prices by 0.54% and rents by 1.08%, implying a marginal willingness to pay for a one-decibel noise reduction of $3,500 for homebuyers and $309 per year for tenants. Even though soundproofing offset roughly half of the noise discount, homeowners do not invest in noise mitigation, because of high upfront costs, split incentives, and information asymmetry. Instead, they adopt reversible avoidance strategies by leaving properties vacant and residing elsewhere until construction subsides. Our findings underscore the importance of incorporating construction-phase externalities and the behavioral responses into project evaluation, and of designing effective compensation schemes to sustain public support for infrastructure investment.

Selected Work in Progress:

• 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:

• Guest Lecturer, Econ 5383, Environmental Economics (Graduate)

• 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

Miscellaneous:

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

• Dog lovers