What happens when the lake gets dirty, the smoke rolls in, or your neighborhood loses its only grocery store? I study how people and businesses adapt, or don't, to environmental and food system shocks, and what that means for policy.
My toolkit: large-scale cellphone mobility data, structural demand estimation, and a healthy obsession with getting causal identification right.
Per- and polyfluoroalkyl substances (PFAS) — known as "forever chemicals" — are persistent synthetic compounds detected widely across the U.S. This dashboard translates PFAS exposure estimates across industrial, drinking water, recreational, and dietary pathways into ZIP-level risk scores, enabling community-level analysis to support targeted environmental health policies.
Uncovering Disparities in Water-based Outdoor Recreation using Cellphone Mobility Data
With Fan, Ji, Zhang · Environmental Research Letters 19 (2024)
Published+
From 70M+ outdoor trips, communities of color, rural areas, and disadvantaged groups are significantly underrepresented in water-based recreation. Native Americans travel 3–5× longer distances.
When Nature Turns Hazy: How Wildfire Smoke Affects Outdoor Recreation
With Yau-Huo Shr and Wendong Zhang · R&R, Journal of Environmental Economics and Management
R&R+
Each additional smoke day reduces visits 13%+. Wildfire smoke caused $21B/year in lost U.S. recreational benefits. Visitors adapt through substitution but only partially offset losses.
I Love That Dirty Water? Value of Water Quality in Recreation Sites
With Christopher R. Knittel and Jing Li
Working Paper+
Using anonymized mobile device data on ~22 million residents visiting 30,000 water recreation sites (2018–2022), recreators are willing to pay $8.20/trip for a one-meter increase in Secchi depth. Improving all sites to the cleanest observed would yield ~$56.3B in annual benefits.
Unequal Waters: Socioeconomic Disparities in Recreational Benefits from Water Quality Improvements
With Fan, Ji, Zhang · Working Paper
Working Paper+
Demand-side factors explain 80–90% of SES welfare gap; geographic access 10–20%. We propose an equity-informed alternative to current Iowa lake restoration prioritization.
How Do Firms Respond to Political Tensions? Chinese Food Importers
With Haoran Li, Wendong Zhang · The World Economy 47(8), 2024
Published+
20% persistent decline in Norwegian fresh salmon imports. "Political hedging" effect: 20% reduction in max import share from any single country three years post-sanction.
Who Goes to Farmers Markets? Food Desert Gaps, Structural Demand, and Policy Design
With Cristina Connolly and Sandro Steinbach
Working Paper+
~70% of food-desert visit gap is demand-side; ~20% supply. SNAP acceptance closes ~18%; evening hours ~33%; one new market per food-desert CBG ~58%. SNAP delivers highest return per public dollar.
Harnessing Human Mobility Data for Applied Economic Research: Current Knowledge, Challenges, and Emerging Opportunities
With Connolly, Steinbach, Vo · Journal of Economic Surveys
Published+
Survey covering contributions of mobility data to travel behavior, labor markets, social interactions, and health outcomes. Addresses measurement errors, sampling biases, and privacy trade-offs.
Causal Recreation Demand Estimation with Cellphone Mobility Data: Evidence from 2021 Huntington Beach Oil Spill
With Nieyan Cheng · Forthcoming, Land Economics · 🏆 Gregory Chow Best Paper, CES 2025
Forthcoming+
$1.03M aggregate welfare loss; $83k/week losses persisted beyond closure. Integrates empirical Bayes into a two-step random coefficient logit model for low-visit sites.
Evaluating Precision, Privacy, and Representation with Cell Phone Data: Evidence from Cape Cod Beaches
With Connolly, Steinbach, Vo · Forthcoming, Land Economics
Forthcoming+
MWTP $8.92/visit under best practices. Differential privacy reduces MWTP by 65%; relaxed dwell time by 57%. Highlights privacy-accuracy trade-offs in non-market valuation.
The Impact of Texas Senate Bill 8 on Family Care Utilization: Evidence from Large-Scale Mobility Data
With Vo, Connolly, Ghosh, Steinbach · R&R, BMJ Public Health
R&R+
Using GPS mobility data from Texas family care clinics (2021–2022), SB 8 increased administrative demands on day-shift practitioners (+8.74 visits/month) while urban patients visited more but spent less time per visit. Rural and suburban patient visits stagnated, highlighting how restrictive abortion legislation disrupts healthcare access for underserved communities.