Energy Saving May Kill: Evidence from the Fukushima Nuclear Accident
Following the Fukushima nuclear accident, Japan gradually shut down all its nuclear power plants, causing a countrywide power shortage. In response, the government launched large-scale energy-saving campaigns to reduce electricity consumption. Exploiting the electricity-saving targets across regions and over time, we show that the campaigns significantly increased mortality, particularly during extremely hot days. The impact is primarily driven by people using less air conditioning, as encouraged by the government. Nonpecuniary incentives can explain most of the reduction in electricity consumption. Our findings suggest there exists a trade-off between climate change mitigation and climate change adaptation.
Forthcoming in American Economic Journal: Applied Economics
Watering Down Environmental Regulation in China
This article estimates the effect of environmental regulation on firm productivity using a spatial regression discontinuity design implicit in China’s water quality monitoring system. Because water quality readings are important for political evaluations and the monitoring stations only capture emissions from their upstream regions, local government officials are incentivized to enforce tighter environmental standards on firms immediately upstream of a monitoring station, rather than those immediately downstream. Exploiting this discontinuity in regulation stringency with novel firm-level geocoded emission and production data sets, we find that immediate upstream polluters face a more than 24% reduction in total factor productivity (TFP), and a more than 57% reduction in chemical oxygen demand emissions, as compared with their immediate downstream counterparts. We find that the discontinuity in TFP does not exist in nonpolluting industries, only emerged after the government explicitly linked political promotion to water quality readings, and was predominantly driven by prefectural cities with career-driven leaders. Linking the TFP estimate with the emission estimate, a back-of-the-envelope calculation indicates that China’s water regulation efforts between 2000 and 2007 were associated with an economic cost of more than 800 billion Chinese yuan.
The Short-Term Impacts of COVID-19 Lockdown on Urban Air Pollution in China
To prevent the escalation of COVID-19 transmission, China locked down one-third of its cities, which strictly curtailed personal mobility and economic activities. Using comprehensive daily air quality data in China, we evaluated the impacts of these measures in terms of the Air Quality Index (AQI) and the concentrations of particulate matter with a diameter of less than 2.5 μm (PM2.5). To infer their causal relationships, we employed difference-in-differences models that compare cities with and without lockdown policies. We found that city lockdowns led to a sizeable improvement in air quality. Within weeks, the AQI in the locked-down cities was brought down by 19.84 points (PM2.5 down by 14.07 µg m−3) relative to the control group. In addition, air quality in cities without formal lockdowns also improved because of the enforcement of other types of counter-virus measures. The AQI in those cities was brought down by 6.34 points (PM2.5 down by 7.05 µg m−3) relative to the previous year. The lockdown effects are larger in colder, richer and more industrialized cities. Despite these improvements, PM2.5 concentrations during the lockdown periods remained four times higher than the World Health Organization recommendations, suggesting much further effort is needed. Existing environmental policies could obtain similar air quality improvements at a much lower economic cost, making city lockdowns an unsustainable option to address environmental issues.
Mitigating the Air Pollution Effect? The Remarkable Decline in the Pollution-Mortality Relationship in Hong Kong
Using transboundary pollution from mainland China as an instrument, we show that air pollution leads to higher cardio-respiratory mortality in Hong Kong. However, the air pollution effect has dramatically decreased over the past two decades: before 2003, a 10-unit increase in the Air Pollution Index could lead to a 3.1% increase in monthly cardio-respiratory mortality, but this effect has declined to 0.5% using recent data and is no longer statistically significant. Exploratory analyses suggest that a well-functioning medical system and immediate access to emergency services can help mitigate the contemporaneous effects of pollution on mortality.
Willingness to Pay for Clean Air: Evidence from Air Purifier Markets in China
Journal of Political Economy, forthcoming
(Working Paper, 2016)
We develop a framework to estimate willingness to pay (WTP) for clean air from defensive investments on differentiated products. Applying this framework to scanner data on air purifier sales in China, we find that households are willing to pay $1.34 per year to remove 1 µg/m3 of PM10 and $32.7 per year to eliminate policy-induced air pollution created by the Huai River heating policy. Substantial heterogeneity in WTP is explained by household income and exposures to media coverage on air pollution. Using these estimates, we examine welfare implications of existing and counterfactual environmental policies in China.
New evidence on the impact of sustained exposure to air pollution on life expectancy from China’s Huai River Policy
Proceedings of the National Academy of Sciences
This paper finds that a 10-μg/m3 increase in airborne particulate matter [particulate matter smaller than 10 μm (PM10)] reduces life expectancy by 0.64 years (95% confidence interval = 0.21–1.07). This estimate is derived from quasiexperimental variation in PM10 generated by China’s Huai River Policy, which provides free or heavily subsidized coal for indoor heating during the winter to cities north of the Huai River but not to those to the south. The findings are derived from a regression discontinuity design based on distance from the Huai River, and they are robust to using parametric and nonparametric estimation methods, different kernel types and bandwidth sizes, and adjustment for a rich set of demographic and behavioral covariates. Furthermore, the shorter lifespans are almost entirely caused by elevated rates of cardiorespiratory mortality, suggesting that PM10 is the causal factor. The estimates imply that bringing all of China into compliance with its Class I standards for PM10 would save 3.7 billion life-years.
Particulate Air Pollution and Mortality in 38 of China’s Largest Cities: Time-Series Analysis
Yin, Peng, Guojun He, Maoyong Fan et al.
The BMJ, 2017, 356: j667.
Objectives: To estimate the short term effect of particulate air pollution (particle diameter <10 μm, or PM10) on mortality and explore the heterogeneity of particulate air pollution effects in major cities in China
Design: Generalised linear models with different lag structures using time series data.
Setting: 38 of the largest cities in 27 provinces of China (combined population >200 million)
Participants: 350,638 deaths (200,912 in males, 149,726 in females) recorded in 38 city districts by the Disease Surveillance Point System of the Chinese Center for Disease Control and Prevention from 1 January 2010 to 29 June 2013.
Main outcome measure: Daily numbers of deaths from all causes, cardiorespiratory diseases, and non-cardiorespiratory diseases and among different demographic groups were used to estimate the associations between particulate air pollution and mortality.
Results: A 10 µg/m3 change in concurrent day PM10 concentrations was associated with a 0.44% (95% confidence interval 0.30% to 0.58%) increase in daily number of deaths. Previous day and two day lagged PM10 levels decreased in magnitude by one third and two thirds but remained statistically significantly associated with increased mortality. The estimate for the effect of PM10 on deaths from cardiorespiratory diseases was 0.62% (0.43% to 0.81%) per 10 µg/m3 compared with 0.26% (0.09% to 0.42%) for other cause mortality. Exposure to PM10 had a greater impact on females than on males. Adults aged 60 and over were more vulnerable to particulate air pollution at high levels than those aged less than 60. The PM10 effect varied across different cities and marginally decreased in cities with higher PM10 concentrations.
Conclusion: Particulate air pollution has a greater impact on deaths from cardiorespiratory diseases than it does on other cause mortality. People aged 60 or more have a higher risk of death from particulate air pollution than people aged less than 60. The estimates of the effect varied across cities and covered a wide range of domain.
Surface Water Pollution and Infant Mortality in China
Economic Development and Cultural Change, 2016, Vol. 65(1), pp. 119-139.
The Effect of Air Pollution on Mortality: Evidence from the 2008 Beijing Olympic Games
Journal of Environmental Economics and Management, 2016, Vol. 79, pp. 18-39.
By exploiting exogenous variations in air quality during the 2008 Beijing Olympic Games, we estimate the effect of air pollution on mortality in China. We find that a 10 percent decrease in PM10 concentrations reduces the monthly standardized all-cause mortality rate by 8 percent. Men and women are equally susceptible to air pollution risks. The age groups for which the air pollution effects are greatest are children under 10 years old and the elderly.
Growth, Pollution, and Life Expectancy: China from 1991-2012
American Economic Review (P&P), 2015, Vol. 105(5), pp. 226-231.