How well connected are the world’s leading science cities?

Although many cities boast multiple research institutions that readily collaborate with each other, research is rarely confined by city limits. The frequency and depth of collaborations between scientists who live and work in different places helps to create strong hubs of research and innovation. When mapping out which cities are collaborating with which, clear differences emerge between China and the United States.

The United States has a much more complex network of collaborations between its cities whereas China’s network is heavily centralized around Beijing and Shanghai.

How to read these charts

This graphics show the 40 biggest collaborations between cities in China and the United States in the Nature Index by bilateral collaboration score for the year 2021. The width of the connections represents the collaboration scores and the size of the circles show a city’s total Share in the Index. The exact Share is also shown numerically. The United States and China represent the leading two locations in the Index by total Share.

China

Beijing acts as the centre of China’s city collaboration network. Many of the leading collaborations are with Beijing, and cities with multiple collaborations tend to have their largest collaboration with China’s capital. Although collaborations in China are mostly centred on either Beijing or Shanghai, a few other nodes are beginning to emerge — most notably in Nanjing.

United States

The city collaboration network in the United States is centred around three primary hubs — the New York metropolitan area (MA), Boston MA and San Francisco Bay Area. Compared with China, there are fewer cities within the US top 40 collaborations, but the cities tend to be more interlinked. Oakridge and Knoxville are not connected to the wider web, but the collaboration score between these two Tennessean cities is significant because they are geographically close to each other, allowing researchers at the Oakridge National Laboratory and universities located in Knoxville to easily work with each other.