News
Examining Global Sustainable Urbanization

China’s urbanization efforts, starting in 1980s, has changed the lives of millions of Chinese nationals, while also altering the world’s political, economic, and environmental landscapes. The MIT China Future City Lab (CFC), a research lab led by Siqi Zheng in the Department of Urban Studies and Planning and Center for Real Estate, focuses on uniting academia, government, entrepreneurs, and industry together to address complex challenges presented by urbanization in China. Under Zheng’s leadership, CFC has recently published several peer-reviewed papers that aim to provide more information for policy makers and urban planners weighing the future of their cities. A selection of three of these papers are highlighted below.

Does the air quality of an urban environment impact the workforce it attracts?
Severe air pollution, often associated with rapidly developing urban environments, imposes significant health and social costs. In their recent paper published in Annuals of Regional Science, Zheng and her coauthors provide direct evidence that air pollution will lead to a city’s “brain drain.” They used the administrative job contract records of all graduate students from a competitive Chinese university in the last decade to model their job location choice, and found that the higher the destination city’s pollution level, the lower the probability of graduates accepting job offers in that city. They demonstrate, if city leaders aim to attract and retain talent in their cities, they must also take immediate steps to mitigate pollution. Read the full article here.

Does clean air increase the demand for consumption in the city?
Cities attract and retain talented young individuals with more than the prospect of employment opportunities, cities also provide a diverse array of leisure opportunities. In a new article published in the Journal of Regional Science, Zheng and her coauthors examine how air quality conditions in a city impact the willingness to partake in leisure activities. They document the leisure complementarity between clean air and urban consumption – people are less likely to visit restaurants and shopping areas if they are aware of the high extent of outdoor pollution. This self-protection lowers their exposure to pollution but also lowers their consumer surplus from social interactions and from living in a vibrant city. Read the full article here.

Does high speed rail promote self-sustaining urban growth?
Human capital is the ultimate engine for long-term economic growth. High skilled workers gain from face to face interactions. If the skilled can move at higher speeds, thanks to transportation innovations, then knowledge diffusion and idea spillovers are likely to reach greater distances. In a new paper published in Journal of Urban Economics, Zheng and her coauthors construct a scientific publication database of 1.5 million journal papers and their authors, and demonstrate that co-author productivity rises (in both quality and quantity) and new co-author pairs emerge when their cities are connected by high speed rail. Their new work documents a synergy between knowledge production and the transportation network – in particular they focus on how high-speed rail enhances Chinese cities’ ability to attract and retain human capital for self-sustaining urban growth. Read the full article here.

From “China Future Cities” to “Sustainable Urbanization”
The increasing trend of urbanization across the global population has fundamental ramifications for our economy, society and the environment. By 2025 cities will generate 88% of global gross domestic product (GDP). Cities also produce more than 70 percent of the world’s greenhouse gas (GHG) emissions and use 80 percent of the world’s energy. Promoting sustainable urbanization is critical to achieving a global development agenda. Reflecting the need to examine sustainable development at a global scale, Zheng introduced three new projects extending the CFC’s analytical framework beyond China to incorporate a global analysis of sustainable urbanization.

“My overarching goal as a scholar is to establish the behavioral foundations for urban and environmental planning and policies aimed at sustainable urbanization. My initial focus has been on China. Through the course of my career development at MIT, I am now extending my analytic framework and research approach to the other most rapidly urbanizing regions of the world,” said Zheng. “With this expansion of focal areas to include a boarder set of countries and cities, including but not exclusive to China, I made the decision to rename the CFC lab to the Sustainable Urbanization Lab (SUL).”

The SUL will be defined by three ‘blocks’: two of which are inter-related research themes: Environmental Sustainability and Place-based Policies and Self-Sustaining Urban Growth; the third block, an educational program the China Future City Program, will continue to serve as the teaching and research center of China’s urbanization on MIT campus.

Asia’s New Cities, SUL’s first project, examines the emergence of “new planned cities” – such as industrial parks, high tech zones, and new smart cities –across Asian countries in the context of national and city leaders explicitly conceptualizing these new cities as a key engine for local economic growth and urban vibrancy. This work will build on comparative studies on the new cities in China, India, Malaysia and South Korea, which will appear in a forthcoming, edited book, Towards Urban Economic Vibrancy: Patterns and Practices of Asia’s New Cities (MIT SA+P Press, 2020). In the second project, Zheng’s team is developing a comparative research approach for studying subway networks and urban vibrancy, and then expand Zheng’s China subway research approach to other cities in the world: Sao Paulo (Brazil), Santiago (Chile), Madrid (Spain), NYC (the US) and Singapore. In their third new initiative, climate change and global sentiment, SUL is constructing a daily city sentiment metric by applying a machine-trained language algorithm (for dozens of popular languages) on the content of billions of geotagged tweets (1.5 billion per year) on Twitter all over the world, to study its dynamics relative to climate change induced extreme weather conditions and disasters, as well as local pollution.