Zhihao Han (韩志豪)

Working papers:

• Preference Malleability When Sustained Information and Experience Interact: Evidence from Bus Electrification (with Alberto Salvo, Timothy Wong, and Wai Yan Leong)

Abstract: While accelerating the green transition demands broad public backing, governments often struggle to effectively connect large-scale infrastructure investments to tangible benefits for the taxpayers funding them. We study whether sustained communication can shift citizen attitudes, preferences, and behavior, in the context of public bus electrification in Singapore. In an RCT with 1,200 households in a neighborhood served by electric buses, half of participants watched video clips across seven encounters highlighting both private and social benefits of electric relative to diesel buses. The video treatment significantly raises satisfaction with electric buses across six co-benefit dimensions, with effects that build gradually and persist through the endline; information provision is most effective among initially skeptical participants and complements direct experience with the technology. Choice experiments administered repeatedly over the campaign show that the treatment increases willingness to pay for electric buses by ten US cents per trip---10% of the average fare, or about one minute of walk time in Singapore's hot climate. Farecard-linked ridership data confirm that stated-preference shifts translate into behavior: treated participants persistently increase electric-bus use through intra-modal substitution, with the strongest effects among the majority without cars and those living near highly electrified bus services. The treatment also shifts general environmental attitudes beyond the transport domain among participants with direct experience of the cleaner technology. Governments that invest in green infrastructure but fail to communicate its co-benefits may forgo the broader self-reinforcing public support that such investments can generate.

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 creates broad social benefits while imposing concentrated local costs, which can trigger strong opposition from nearby communities. We study this form of NIMBYism in the context of High Speed 2, one of the largest rail infrastructure projects under construction in Europe. After the project's statutory authorization, transaction prices exhibit a U-shaped discount gradient with distance from the route, falling by up to 5% in the 3–6 km band, while rents respond more modestly. Construction disamenities account for 72% of the gross transaction-price capitalization and 60% of rental capitalization, with anticipated operational benefits and compensation partially offsetting these losses. We then identify construction noise as a key mechanism. 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 a shift-share instrumental-variable design within a hedonic framework, we estimate that a 1 dB increase in daytime construction noise reduces transaction prices by 0.54% and rents by 1.08%, implying marginal willingness to pay for a 1 dB noise reduction of $3,500 for homebuyers and $309 per year for tenants. Although soundproofing attenuates roughly half of the noise discount, we find little evidence of new investment in noise mitigation; instead, affected homeowners leave properties vacant and reside elsewhere while waiting for construction to end. Overall, incorporating construction externalities into ex ante appraisal, mitigation, and compensation scheme design is essential for sustaining public support for socially valuable projects.

Selected Work in Progress:

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

• Building for Yesterday's Rain? Local Rainfall Formulas, Information Lags, and Urban Flood Risk in China (with Yaming Lei and Mingwei Yu)

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

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