Clean Air in Consumer Cities
Projects
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Does Clean Air Increase the Demand for the Consumer City?
Evidence from Beijing
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Air Pollution and Elite College Graduates’ Job Location Choice
Will graduates consider the level of air pollution in the destined cities when accepting job offers? Is there a tendency of choices? Does it vary according to students' degrees?
Evidence from Tsinghua University
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Self-Protection from Smog
Inequality in pollution exposure between low- and high-income households
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Publications
Our publications related to these projects
Does Clean Air Increase the Demand for the Consumer City?
Evidence from Beijing
Yearly mean PM2.5 concentration levels in Beijing, New York and Los Angeles
Consumer cities offer a variety of leisure opportunities. However, the gains from such consumer city leisure are likely to be lower on more polluted days.
We study the association between daily consumption activity and outdoor air pollution in China and find evidence in favor of the hypothesis that clean air and leaving one's home for leisure trips are complements.
Demand of the urban consumer city will increase when air pollution is lower.
Causal Impact
A 10 percent increase in the PM2.5 concentration will lead to a decrease of consumer activities by:
This impact will also exacerbated on hot days - the magnitude is about 3-4 times larger for the same amount of the PM2.5 concentration level increase.
Kernel-based estimation of the semiparametric restaurant regression.
Rebound Effect
Patient people engage in intertemporal substitution and delay their leisure trips to days featuring better air quality. This behavioral response will lead to a rebound effect, such as a spike in leisure activities on the first blue sky day after several consecutive polluted days.
One additional "severely polluted" day is associated with:
Heterogeneous Effect
There is a larger increase in visits for higher‐quality restaurants during blue sky days. In particular, blue sky has a negative or little impact on visits to low‐quality restaurants.
The results show that the visits of Chinese cuisine restaurants are higher under excellent or good air quality, compared with foreign cuisine restaurants.
The impact of blue sky on fast food restaurant reviews is relatively small compared with restaurants serving table meals.
Team
Siqi Zheng
MIT Sustainable Urbanization Lab, Department of Urban Studies and Planning,
Center for Real Estate
Jianghao Wang
Chinese Academy of Sciences
Matthew Kahn
Johns Hopkins University and NBER
Cong Sun
Shanghai University of Economics and Finance
Air Pollution and Elite College Graduates’ Job Location Choice
Will graduates consider the level of air pollution in the destined cities when accepting job offers?
Is there a tendency of choices?
Does it vary according to students' degrees?
- Evidence from Tsinghua University
Various media outlets have reported that severe air pollution in China impedes cities’ capacity to recruit and retain talent.
Air quality is crucial urban livability characteristics that affect behaviors and actions among people daily. As severe air pollution brings significant health and social cost to urban residents, it might also become a factor for decision-making of where to live.
In China, when college graduates search for their first jobs, they regard air quality as a critical consideration when choosing which city to work in.
We want to quantify the impact of air pollution on the job location choice of the highly educated labor force.
We merge air quality data gathered from remote sensing instruments with an administrative dataset of job contract data for graduates from Tsinghua University, one of China’s top 2 universities, from 2005 to 2016.
In order to identify the casual effects of air pollution on job location choice, we introduce city fixed effects and year fixed effects, and control for city’s time-variant local attributes in terms of economic development level, labor demand, living cost, public services, and weather conditions.
We find that air pollution has a significantly negative effect on the probability of elite graduates accepting job offers in a city.
Whether to Stay in Beijing?
When Beijing’s air pollution is much worse than that for other major cities (a higher relative ratio), it significantly reduces the likelihood that students choose to stay in Beijing after graduation.
Which city to move to?
Having a higher level of air pollution is found to have a significantly negative effect on the probability of elite graduates accepting a job offer in a city.
- This “crowding - out” effect is larger and more significant for graduate students than undergraduate.
- Later graduates are influenced by earlier cohorts’ job location choices.
If the ratio of Beijing’s PM2.5 concentration to other large- and medium-sized cities’ average level increases by 0.1, which indicates worse air quality compared to other cities, the probability of staying in Beijing will decrease by 0.7 percentage point.
All else equal, if PM2.5 increases by 10 μg/m3, the share of Tsinghua graduates accepting job offers in that city will decrease by 0.23 percentage point.
Heterogeneous effect
- Student Groups
Males, Tsinghua Environmental School graduates, those who grew up in cleaner provinces, and those who major in engineering care more about the air quality of their future city of residence.
- Information Transparency
Given the PM2.5 concentration level, more new reports will further lower the probability that a city is chosen. This means better information transparency will improve students’ knowledge of air pollution in target cities, and further influence their decision choice.
- Trend Throughout Years
Students are becoming less sensitive to air pollution over time. The signal then gives residents an impression that air pollution in urban areas will sooner or later be less of a concern, leading to reduced sensitivity.
Team
Siqi Zheng
MIT Sustainable Urbanization Lab, Department of Urban Studies and Planning,
Center for Real Estate
Xiaonan Zhang
Hang Lung Center for Real Estate, and Department of Construction Management, Tsinghua
University
Weizeng Sun
School of Economics, Central University of Finance and Economics
Chengtao Lin
Career Development Center, Tsinghua University
Self-Protection from Smog
Inequality in pollution exposure between low- and high-income households
Research has previously shown that air pollution is damaging to our health, productivity, and education. Apart from government regulations to reduce emissions, individuals can invest in protective equipment, such as masks and air filters, to reduce their exposure to air pollution.
Do people tend to buy more masks and air filters when air quality is bad?
Do spending patterns differ between low- and high-income households?
A comparison of two air pollution protection products
Air filters may cost more than masks, but they are much more effective at filtering out air pollution. However, not everyone can afford to invest in more expensive air filters, and this may lead to inequality in pollution exposure.
We looked at 34 cities using sales data from Taobao.com, China's largest online shopping platform
To investigate spending differences between low and high-income households, we collected monthly sales data from April 2013 to April 2014 for low, medium, and high-income groups
To understand people’s spending response to bad air quality, we compared daily sales data from Nov 1, 2013 to Jan 31, 2014 to PM2.5 concentration data and daily pollution alerts from China’s Ministry of Environmental Protection (MEP).
People invest more in masks and filters when air pollution is bad
People respond to both government pollution alerts and actual PM2.5 concentration levels by buying more masks and air filters.
People's spending response increases as polluted levels get worse. People tend to buy more masks than air filters.
People spend more on masks than air filters on badly polluted days, possibly due to the cheaper cost of masks.
Inequality in air pollution exposure
People with higher incomes invest more in smog protection, especially in more expensive and effective products. Whereas, individuals in the low-income group buy significantly more masks but not air filters
Low-income people are about 2.5x more likely to purchase masks than high-income people.
High-income people are about 3x more likely to purchase air filters than low-income people.
High and medium-income people tend to purchase more air filters, which are more expensive but more effective, compared to low-income people.
This difference in cost and effectiveness of protection equipment and spending between low and high income groups means that there is inequality in air pollution exposure which impacts the quality of life in Chinese cities.
Given widespread concerns about the consequences of income inequality in both the United States and China, it remains an important research topic to study how and why different income levels are exposed to different air pollution levels.
Team
Siqi Zheng
MIT Sustainable Urbanization Lab, Department of Urban Studies and Planning,
Center for Real Estate
Cong Sun
Shanghai University of Economics and Finance
Matthew Kahn
Johns Hopkins and NBER
Publications
Sun, C., Zheng, S., Wang, J., & Kahn, M. E. (2019). Does clean air increase the demand for the consumer city? Evidence from Beijing. Journal of Regional Science.
Zheng, S., Zhang, X., & Sun, W. (2019). Air Pollution and Elite College Graduates' Job Location Choice: Evidence from China. Annals of Regional Science.
Sun, C., Kahn, M. E., & Zheng, S. (2017). Self-protection investment exacerbates air pollution exposure inequality in urban China. Ecological economics, 131, 468-474.