The global population — 7.8 billion and counting — is the largest it’s ever been. And most of the world’s people now live in cities. As urban areas have grown, these centers of government, commerce, innovation, and social interaction have become increasingly complex. The usual tools for understanding them — urban geography, sociology, economics, and so on — no longer suffice. To grasp the totality of today’s cities and devise the best solutions to address urban problems, we need a new, interdisciplinary approach that builds upon all of these realms of knowledge and a lot of new data while offering a new way of thinking about cities, argues Santa Fe Institute External Professor Luís Bettencourt in his new book, Introduction to Urban Science: Evidence and Theory of Cities as Complex Systems.

Urban science “is essentially about creating knowledge that allows us to understand and predict the processes that create cities,” says Bettencourt, who is Professor of Ecology and Evolution and Inaugural Director of the University of Chicago’s Mansueto Institute of Urban Innovation. While the study of cities is nothing new, there was a need for a comprehensive guide to the properties of cities as complex, evolving systems, he says. For the most part, urbanization is occurring without deliberate planning, and insights from urban science can help cities adapt to the challenges that come with growth and change. The book provides readers with a solid understanding of the classical models of cities and complex networks before delving into key features of urban areas, from diversity, economic productivity and infrastructure to geography, growth, and institutions, and how they’re connected.

“The book makes the point again and again that cities are not just the things you see when you look out the window,” Bettencourt says. “Cities are people in action, change, networks.”

Bettencourt says he hopes anyone who studies cities or teaches urban science will find the book, which draws on a course he teaches at the University of Chicago, useful. “I hope that this book settles some old questions but also that many new ones arise,” he writes in the preface. 

Buy the book, Introduction to Urban Science: Evidence and Theory of Cities as Complex Systems (MIT Press, 2021)

Read the "Books in brief" review in Nature (September 30, 2021)

Listen to the "Science of Cities" episode with Luís Bettencourt on SFI's Complexity Podcast.


Cities have always been conceptualized — philosophically at least — as complex systems either in their own right or through analogies to organisms, beehives, ecosystems, nervous systems, and other things. However, a couple of seconds’ reflection immediately manifests the insufficiency of any of these metaphors. For example, cities are much larger, achieve much higher power densities, and create new information much more quickly than any of these other complex systems. Cities, in fact, are made by connecting all these different complex systems together in specific ways, generating a new ‘metadynamics’ that appears more complex and open-ended than any of its parts...