Hi, I'm Yixin Sun, but most people call me Sunny.

I am an environmental economist at the Centre for Net Zero, where I use experimental and quasi-experimental methods to study how we can build a sustainable energy system.

I completed my PhD in economics at the University of Chicago Booth School of Business, where my research focused on the intersection of environmental and development economics. Much of my dissertation work examined how people perceive and adapt to air pollution in developing settings. During the PhD, I was a DRW PhD Fellow at University of Chicago's Energy Policy Institute.

I am also engaged in community-driven research as a Community Science Fellow in the American Geophysical Union's Thriving Earth Exchange, collaborating with local partners on projects that link scientific evidence with real-world community priorities.

Yixin (Sunny) Sun

working papers

Hourly electricity demand: baseline vs. EV tariff

AI in Charge: Large-Scale Experimental Evidence on Electric Vehicle Charging Demand

with Robert Metcalfe, Andrew R. Schein, and Cohen Simpson

Abstract

One of the promising opportunities offered by AI to support the decarbonization of electricity grids is to align demand with low-carbon supply, yet there is little causal evidence on household acceptance of AI managed control, and its impact on their consumption. We evaluated the effects of the world's largest AI managed EV charging tariff (a retail electricity pricing plan) using a large-scale natural field experiment. This tariff is designed to optimize EV charging by dynamically controlling charging in response to real-time wholesale electricity prices. We randomized financial incentives to encourage enrollment onto the tariff and observed consumption for more than a year. We found that the tariff led to a 42% reduction in household electricity demand during peak hours, with 100% of this demand shifted to lower-cost and lower-carbon-intensity periods. The tariff generated substantial consumer savings, while demonstrating potential to lower producer costs, energy system costs, and carbon emissions through significant load shifting. Overrides of the AI algorithm were low, suggesting that this tariff was likely more efficient than a real-time-pricing tariff without AI, given our theoretical framework. We also showed that experimental estimates differed meaningfully from those obtained via non-randomized difference-in-differences analysis, due to differences in the potential outcomes of the samples in the two evaluation strategies, although we can reconcile the estimates somewhat with observables. Our findings highlight the potential for scalable managed charging and its substantial welfare gains for the electricity system and society.

Indoor and outdoor PM2.5 levels over time in Jakarta

High Indoor Air Pollution in a Developing Megacity: The Role of Outdoor PM2.5 and Household Characteristics

with Dil Rahut, Budy P. Resosudarmo, Jeanne Sorin, and Daniel Suryadarma

Revise & Resubmit at the Proceedings of the National Academy of Sciences

Abstract

Exposure to fine particulate matter (PM2.5) poses major health risks, especially in rapidly urbanizing cities. As urbanization accelerates, people in low- and middle-income countries spend more time indoors, where pollution risks remain poorly understood. We present evidence from over 152,000 monitor-hours of indoor PM2.5 measurements across homes in Jakarta, Indonesia, one of the world's largest and most polluted cities. We find that mean daily indoor and outdoor PM2.5 levels are both dangerously high, eight times above World Health Organization's (WHO) health-based guidelines. In addition, indoor PM2.5 frequently reach hazardous levels — 40 to 100 times the WHO guideline, levels that outdoor monitors do not capture. Unlike in developed settings, most indoor pollution originates from outdoor infiltration. Survey data also reveal large inequalities: lower-income households experience double the mean indoor PM2.5 of higher-income households. Our findings show that indoor air pollution remains both severe and unequally distributed, even in this population where most people have adopted cleaner cooking fuels. Researchers and policymakers should integrate outdoor air quality mapping with demographically representative indoor monitoring to close key data gaps, enabling more accurate exposure estimates and better-targeted environmental health policies.

works in progress

Learning is in the Air: Clean Air as an Experience Good

with Budy P. Resosudarmo and Jeanne Sorin

Accepted, Journal of Development Economics Pre-Results Review · AEA RCT Registry No. 0013110

Abstract

Despite the severe health risks posed by air pollution, demand for cleaner air remains slow in many highly polluted developing regions. One potential explanation is that clean air functions as an experience good: where personal demand becomes evident only after consuming cleaner air. We provide the first experimental test of clean air as an experience good by randomly assigning households in Jakarta, Indonesia to a three-month air purifier rental. Our findings reveal that purifier rentals effectively reduced indoor PM2.5 concentrations by 33%, demonstrating that the intervention successfully exposed households to clean air. Households that experienced cleaner air felt the purifiers improved their health, and developed stronger beliefs about the benefits of clean air. The treatment increased WTP for air purifiers, but only among households with above-median income, suggesting that financial constraints limit demand despite learning effects.

Draft available upon request.

A Demand-Side Alternative to Renewable Curtailment: Natural Field Experimental Evidence from Two Countries

with Daniel Lopez Garcia, Robert Metcalfe, and Andrew R. Schein

other writings