SFI External Professor Luís Bettencourt and co-author Nicholas Marchio, both researchers at the University of Chicago, use the first complete dataset of more than 415 million buildings across 50 countries in sub‐Saharan Africa to create an unprecedented approach to urban development, down to each street block.
Published in Nature, their analysis introduces “block complexity” — a measure of how difficult it is to provide street access to every building in a neighborhood.
Blocks with higher complexity are more likely to lack piped services, legal addresses and emergency access — features typical of informal settlements. The researchers estimate that more than half a billion people in the region live in high-complexity areas, which includes rural communities and peri-urban settings between rural and urban zones.
“This paper shows how we can measure and then begin to address those deficits for each household in every building, anywhere in the world,” Bettencourt says.
This work came out of a long term project started at the Santa Fe Institute, to develop a predictive theory of urban networks. It provides a new way for local governments, NGOs, and development agencies to identify where infrastructure improvements are most needed and to plan solutions down to the block level.
Read the paper “Infrastructure deficits and informal settlements in sub-Saharan Africa” in Nature (September 03, 2025) at DOI: 10.1038/s41586-025-09465-2
Read the press release from the University of Chicago (September 03, 2025)