Kaiyi Wen (温开一)
Working Papers & Work in Progress
(Working Paper)
The Hidden Toll: Public Health Burden of Illicit Opioid Market Shifts
(with Xiaolong Hou, Yichu Li, Donglan Zhang, and Zhuo Chen)
This paper estimates the causal impact of a major supply-side shock in the U.S. illicit opioid market. Beginning in 2012, Mexican drug trafficking organizations displaced Colombian suppliers and took control of white-powder heroin distribution in the Eastern U.S. This transition raised the mean and variance of heroin purity and facilitated widespread fentanyl adulteration. Using 2004–2019 discharge-level data from the National Inpatient Sample and an event-study design, we show that this shift led to a 73 percent (0.11 percentage point) increase in heroin overdose inpatient admissions in affected regions. Placebo tests using alcohol poisoning and cocaine show no comparable effects, while spillovers to fentanyl- and methadone-related admissions are positive but imprecise. The effects are concentrated among Medicaid-covered and self-pay patients, indicating substantial public sector exposure. We estimate direct medical costs of approximately $4 billion, but the total welfare loss is far larger once accounting for excess mortality, reduced labor force participation, and intergenerational deficits in human capital.
(Working Paper)
Neglected Hazard: Mental Health and Roadway Noise
(with Neha Khanna, presented at AERE 2023 Summer Conference, 2023 HINTS Data Users Conference, *PSU AGSE Seminar, *Delhi School of Economics Seminar, *MEA 2024 Annual Conference, CES 2024 North America Conference, *Indian Statistical Institue Seminar, September 2024 OSWEET Online Workshop, 2024 Heartland Workshop, Global GLO-JOPE Conference 2024, 2025 ASSA Annual Meeting. * indicates presented by the coauthor)
Poor mental health triggers serious labor market penalties and is a growing cause for concern among health professionals and economists. Using restricted data on approximately 14,000 survey respondents combined with spatially detailed national noise maps, we estimate that road noise is associated with sleep deprivation and has a statistically significant, causal effect on mental health, equivalent to a 12.7% increase in the number of respondents experiencing mild symptoms. This translates to an annual welfare loss as large as $12.8 billion for the US.
Previously circulated as: Beyond the Haze of Air Pollution: Traffic Noise and Mental Health (with Neha Khanna; 2024)
(Working Paper) - Under review
As Time Goes By: Redlining, Kinship, and Environmental Justice
(with Neha Khanna, presented at AERE 2024 Summer Conference, 2024 NAREA Annual Meeting and Workshop, SEA 94th Annual Meeting, *MEA 2025 Annual Conference, *WEAI 100th Annual Conference. * indicates presented by the coauthor)
We contribute to the literature on environmental justice by exploring the role of two relatively unexplored factors, redlining and kinship, in explaining the environmental pollution gap between marginalized and non-marginalized communities. Using restricted data on 23,000 survey respondents in the contiguous US, we measure onsite emissions, ambient road noise, and PM2.5 concentrations at the individual and community levels. We find that individuals identifying as Black are exposed to higher levels of all three pollutants as compared to White individuals. However, the results are sensitive to geographic scale and it matters whether we measure pollution at the local (i.e. individual) or neighborhood scale. Overall, our results suggest that while neighborhoods with higher shares of African Americans have no greater ambient pollution than relatively white neighborhoods, within these neighborhoods, individuals of color may still be disproportionately exposed to pollutants as compared to white individuals.
(Working Paper) - Submitted
Behind Environmental Injustice: Disparate Siting and Post-Siting Migration of Fossil Fuel Power Plants
(with Ruohao Zhang, and Huan Li, presented at *2023 ASSA Annual Meeting. * indicates presented by the coauthor)
Environmental injustice can be explained by two mechanisms: the disproportionate siting of polluting industries in low-income and minority communities, and demographic changes following the establishment of toxic sites. This paper investigates the siting decision of fossil fuel power plants and the subsequent demographic changes due to the siting in the context of environmental injustice. Using data at census tract level in the United States from 2000 and 2019, we find that fossil fuel power plants are more likely to be located in areas with higher minority populations, which leads to an average increase in the local minority ratio by 1.2%.
​(Working Paper)
Too Shiny to Handle: Nighttime Light and Mental Health
(with Yushang Wei, presented at *SEA 94th Annual Meeting, EEA 51st Annual Conference, AERE 2025 Summer Conference. * indicates presented by the coauthor)
Poor mental health imposes significant labor market penalties and is a growing concern among health professionals and economists. While several factors are linked to poor mental health, the role of non-chemical environmental factors remains unclear. Meanwhile, the average night sky has become brighter by 9.6% per year since 2011. This excessive light usage results in substantial welfare losses and health problems. We conduct the first study to establish a causal relationship between light pollution and mental health in the US. Using restricted data on approximately 14,000 survey respondents and granular nighttime light data from NASA, we exploit variations in local cloud cover to establish the exogenous change in nighttime light pollution. Our findings demonstrate that 2.7% of respondents who previously reported minimal mental health concerns are now showing mild symptoms of mental health issues. This translates to an annual welfare loss of up to $47 billion attributed to lost earnings in the labor market.
​(Working Paper) - Submitted
Using a panel of Chinese cities over the period 1999 - 2018, we examine the determinants of economic growth, focusing on the role of foreign direct investment (FDI) and road infrastructure. Consistent with the predictions of a human capital-augmented Solow model, we find that FDI has a positive effect on the per capita GDP growth rate and this effect is intensified by the road infrastructure of the city. The latter suggests one way that road infrastructure contributes to growth is to serve as a facilitator for technology transfers stemming from FDI. The findings suggest the complementary effect of FDI on road infrastructure is stronger for technology-intensive cities, coastal regions, and first-tier cities. The results are robust to alternative model specifications and estimation methods.
​(Working Paper)
Energy Transition and Mental Health
(with Jancy Liu, Dylan Brewer, and Yueming (Lucy) Qiu *2025 ASSA Annual Meeting, *AERE 2025 Summer Conference. * indicates presented by the coauthor)
We provide quasi-experimental estimates of the impact of coal and natural gas power plant retirements on the mental health of local residents in the United States. Combining data on power plant retirements and restricted mental health data, we employ a difference-in-differences approach and find that coal-fired power plant retirements have a significant negative impact on mental health, while natural gas retirements have a positive effect. We explore potential mechanisms and find evidence suggesting that economic impacts and local amenity improvements drive these divergent effects. Our findings highlight the importance of considering mental health implications in energy transition policies and strategies.
​(Working Paper)
Taxing Addiction in Hard Times: Cigarette Taxes and Smoking During Recessions
(with Hyeran Chung, Xiaolong Hou, Yichu Li, and Yeongmi Jeong)
This paper examines whether individuals' behavioral responses to cigarette taxes shifted during the Great Recession. Using repeated cross-sectional data from the Behavioral Risk Factor Surveillance System (BRFSS) between 2003 and 2009, we estimate linear probability models to assess the association between cigarette tax increases and smoking cessation behaviors before, during, and after the recession. Our empirical strategy exploits variation in state-level cigarette taxes and their interaction with a recession-period indicator, while controlling for demographic characteristics, state and year fixed effects, and state unemployment insurance generosity. Contrary to standard economic predictions, we find that individuals were less responsive to cigarette tax increases during the recession, even though overall quit attempts modestly increased. Heterogeneity analyses reveal that this diminished responsiveness was particularly evident among lower-income individuals and those without health insurance - groups more vulnerable to financial and psychological stress. These results suggest that economic downturns may constrain individuals' capacity to respond to price-based health policies, with important implications for the timing, equity, and effectiveness of tobacco control strategies.
​(Working Paper)
Equal Rights, Better Mental Health? The Impact of Non-Discrimination Laws on LGBQ Youth
(with Hyeran Chung, Xiaolong Hou, Yichu Li, and Molin Qin)
Youth suicide has become a growing public health and economic concern in the United States, with sexual minority adolescents facing disproportionately high risks. This paper provides the first evidence on the effects of state-level nondiscrimination laws (NDLs) that explicitly protect sexual minorities on youth mental health. Using nationally representative data from the Youth Risk Behavior Surveillance System and variation in the timing of NDL adoption across states, we estimate a fully interacted difference-in-differences model comparing sexual minority and heterosexual youth before and after implementation. We find that NDLs lead to significant reductions in suicide attempts among sexual minority adolescents, with results robust to controlling for anti-bullying laws, same-sex marriage legalization, demographic characteristics, and state and year fixed effects. We also document declines in bullying and risky behaviors such as smoking and alcohol use, consistent with improved underlying mental health.
(Selected Work in Progress)
The Impact of Health Insurance Transition: Evidence from El Paso
(with Hyeran Chung)
Persistence in Environmental Exposure: Evidence from Anchoring
(with Huan Li, Ruohao Zhang, and Neha Khanna)
Highway Noise Pollution and Infant Health Outcomes: Evidence from California
(with Huan Li, Ruohao Zhang, and Neha Khanna)