Working Papers
"Levees and levies: Local financing of climate infrastructure maintenance and housing market dynamics" (Revise and Resubmit, American Economic Journal: Applied Economics)
Local financing of climate infrastructure structurally connects infrastructure quality with housing value through property tax revenue. I study how this connection shapes the long-term dynamics of neighborhood housing value and climate risk. Using novel data on U.S. flood protection levees, I show that lower-income neighborhoods are disproportionately behind levees of maintenance deficiencies, leading to higher levee failure risk. Exploiting exogenous shocks to local economic conditions and levee failures, I find that weaker housing markets degrade levee maintenance, while levee failures in turn reduce housing values and local revenues. These bi-directional dynamics reinforce a feedback loop of fiscal stress and climate vulnerability, contributing to underinvestment in infrastructure with positive net benefits.
"Portfolio pricing of disaster risk in commercial real estate insurance market" with Dongxiao Niu, Thomas Williams, Siqi Zheng
Institutional investors in commercial real estate do not buy insurance coverage one property at a time; they negotiate it for their entire fund portfolio. Matching property-level insurance expense from the National Council of Real Estate Investment Fiduciaries (NCREIF) to modeled expected disaster damage from Moody's Risk Management Solutions (RMS), we find that a property's insurance cost depends on the fund portfolio it sits in. Holding own hazard exposure fixed, insurance expense rises with the mean risk of the fund portfolio and falls with the fund's scale and risk diversification. A transaction-based design that tracks the same property as it moves between funds with different risk profiles confirms the pattern.
"Cross-regional attention networks in climate disasters: Mapping asymmetric spillovers and blind spots" with Yilan Xu, Siqi Zheng, Zhentao Shi, Yi Huang, Sebastien Box-Couillard (Minor Revision, Journal of Economic Geography)
We introduce an innovative machine-learning enhanced variance decomposition method to uncover the spatial network structure of climate information transmission using high-frequency social media data. Our findings reveal the structure and determinants of climate disaster information networks and pinpoint locations with high disaster risk yet limited information connectivity. Our approach is adaptable to different geographic scales and its capacity to capture real-time information dynamics can facilitate timely interventions and resource allocation during public crises.
"Observing the unobservable: Connecting persistent emotional state to behavior in risky contexts" with Jude Bayham, Eli Fenichel, Juan Palacios, Siqi Zheng
Economists rely on experiments and surveys to measure typically unobserved subjective attributes, e.g., emotional state, which often are important in understanding behavior. Dependence on these data collection modes limits the ability to connect subjective traits with behavior. We use social media posts and natural language processing to infer individuals' persistent emotional state and link this attribute to the behavior of 500,000 individuals during the COVID-19 pandemic. We find that persistent fear propensity has significant moderating effects on social distancing behaviors and can be used to target interventions at scale.
Selected Work in Progress
"Dynamic development responses to flood protection: Implications for valuing climate adaptation infrastructure" with Martin Smith, Farshid Vahedifard, Jianxing Wan
"Incentive dynamics in climate resilience systems: Insurance, public infrastructure, and private adaptation" with Martin Smith, Craig Landry (Supported by CIRCAD)
"Do rising property insurance prices suppress housing investment?" with Abigail Ostriker
"Defending the coasts: Seawalls, typhoons, and adapting to sea-level rise" with Yuqi Song, Rongjie Zhang (2026 APJRI Research Excellence Award)
"Heat and the geography of tourism losses" with Shiyue Luo, Ernani Choma
"A harmonized national work-type classification of 150 million U.S. building permit records" with Candy Martinez, Sean Hardesty Lewis, Siqi Zheng
Selected Publications
"Global physical activity resilience during the COVID-19 pandemic: an observational study of 5.17 million exercise app users across 65 countries" with Yuchen Chai, Fábio Duarte, Stephanie Jegelka, Siqi Zheng
BMJ Public Health, 2026
Public health hazards, such as extreme temperatures, air pollution, and pathogens, pose challenges for physical activity (PA) adherence due to voluntary or mandatory self-protection measures. We collected exercise records across more than 60 countries from Strava, a PA self-tracking app, and investigated the drivers of PA adherence during the COVID-19 pandemic. We use neural network methods to automate the characterize of PA adherence prior and during the pandemic based on personal exercise habits and social network interactions, and use an explainable neural network approach with econometric analysis to reveal the impact of city-level policies, socio-demographics, and built environment factors on PA adherence.
"Unequal impacts of rising temperatures on global human sentiment" with Jianghao Wang, Nicolas Guetta-Jeanrenaud, Juan Palacios, Devika Kakkar, Nick Obradovich, Siqi Zheng
One Earth, 2025
Estimating the potential impact of climate change on human emotional well-being is a critical component of understanding the manners in which future climatic changes may undermine human mental health. We analyze over 1.2 billion social media posts from 157 countries to reveal how rising temperatures affect human sentiment worldwide and project future impacts under climate scenarios. We find that temperatures above 35°C negatively impact emotional well-being globally, with effects three times greater in low- and middle-income countries (25.0% decline in sentiment) than in high-income countries (8.1%). Even accounting for climate adaptation through income growth, global sentiment will be significantly lower by the end of this century.
"Social cost of lifestyle adaptation: air pollution and outdoor physical exercise"
Journal of Environmental Economics and Management, 2024
The social cost of environmental hazards depends on the well-being impacts of both exposure and adaptation. While the monetary expenditure of adaptation is increasingly considered, little research assesses the social cost and inequality associated with non-market lifestyle adaptation. I present novel evidence regarding how urbanites adjust their outdoor physical exercise in response to air pollution and related information policies using 27 million exercise records from a smartphone exercise app. I quantify the health cost associated with foregone exercise, analyze the distributional consequences, and present implications for environmental and health policies.
"Intraday adaptation to extreme temperatures in outdoor activity" with Jianghao Wang, Nick Obradovich, Siqi Zheng
Scientific Reports, 2023
Linkages between climate and human activity are often calibrated at daily or monthly resolutions, which lacks the granularity to observe intraday adaptation behaviors. Ignoring this adaptation margin could mischaracterize the health consequences of future climate change. We construct an hourly outdoor leisure activity database using billions of cell phone location requests in 10,499 parks in 2017 all over China. We then use climate econometrics to investigate the within-day outdoor activity rhythm in response to extreme temperatures and project the impacts of future climate change.
"Global evidence of expressed sentiment alterations during the COVID-19 pandemic" with Jianghao Wang, Juan Palacios, Yuchen Chai, Nicolas Guetta-Jeanrenaud, Nick Obradovich, Chenghu Zhou, Siqi Zheng
Nature Human Behavior, 2022
The COVID-19 pandemic has created unprecedented burdens on people’s physical health and subjective well-being. While countries worldwide have developed platforms to track the evolution of COVID-19 infections and deaths, frequent global measurements of affective states to gauge the emotional impacts of pandemic and related policy interventions remain scarce. Using 654 million geotagged social media posts in over 100 countries, coupled with natural language processing, we develop a global expressed sentiment dataset and identify the affective effects of COVID-19 and lockdown policies.
"Encouraging the resumption of economic activity after COVID-19: evidence from a large scale-field experiment in China" with Juan Palacios, Erez Yoeli, Jianghao Wang, Yuchen Chai, Weizeng Sun, David G Rand, Siqi Zheng
Proceedings of the National Academy of Science (PNAS), 2022
As the COVID-19 pandemic comes to an end, governments find themselves facing a new challenge: motivating citizens to resume economic activity. What is an effective way to do so? We investigate this question using a field experiment in the city of Zhengzhou, China, immediately following the end of the city’s COVID-19 lockdown. We assessed the effect of a descriptive norms intervention providing information about the proportion of participants’ neighbors who have resumed economic activity.
"Health perception and commuting choice: a survey experiment measuring behavioral trade-offs between physical activity benefits and pollution exposure risks" with Juan Palacios, Mariana Arcaya, Rachel Luo, Siqi Zheng
Environmental Research Letters, 2021
Previous literature suggests that active commuting has substantial health benefits. Yet, in polluted regions, it can also cause additional health risks by increasing riders' pollution exposure and raising their inhalation rate. We examine the effect of perceived air pollution on stated commuting choices using an on-site survey experiment for 2,285 commuters in Zhengzhou, a heavily polluted city in central China. The results from our randomized controlled trial show that pollution avoidance tendency significantly attenuates the effect of policies encouraging active commuting, suggesting intertwined relationships between different public health targets.
"Dockless bike sharing alleviates road congestion by complementing subway travel: Evidence from Beijing" with Siqi Zheng
Cities, 2020
Dockless bike sharing provides a flexible transportation alternative, enriching the potential of both a feeder mode for subway access and a direct substitute for subway trips. We use 3.2 million geo-coded bike-sharing trips to evaluate the interaction between dockless shared bikes and the existing subway system in Beijing. Employing a generalized Difference-in-Differences identification strategy, we find that subway lines with high bike-sharing intensity showed an 8% larger growth rate in subway ridership, and the rush hour road congestion around those subway stations drops by 4%. We demonstrate that the synergy between dockless bike sharing and the subway system outweighs substituting effects and can help achieve a greener and healthier city.
"Low-carbon innovation induced by emissions trading in China" with Junming Zhu, Xinghua Deng, Lan Xue
Nature Communications, 2019
Emissions trading scheme (ETS) has been adopted by an increasing number of countries and regions for carbon mitigation, but its actual effect depends on specific program design and institutional context. We provide firm-level evidence of the innovation effect directly from China’s pilot emissions trading, based on latest patenting information and a quasi-experimental design. We show that China’s pilots increase low-carbon innovation of ETS firms by 5–10% without crowding out their other technology innovation, and the effect is driven by mass-based allowance allocation.