Infrastructure deficits and informal settlements in sub-Saharan Africa.

Abstract

Sustainable development is an imperative worldwide^1-3 but metrics and data on poverty and quality of life have remained too coarse and abstract to characterize challenges adequately and guide practical progress^4,5. Nowhere is this challenge greater than in Africa^4-6, where we still know little about the spatial details of development^3,7-9. Here we leverage a comprehensive, high-precision dataset of building footprints to identify infrastructure deficits and infer informal settlements down to the street block level^10-12 everywhere in sub-Saharan Africa. We identify a general pattern of informality with cities showing, on average, greater access to infrastructure and services than rural and peri-urban areas. We show that such patterns of informality are characterized by consistent statistical distributions reflecting uneven local development^2,13,14. We also show that these physical measures of informality are systematically associated with many indicators of human deprivation, which form a single principal component co-varying predictably with specific changes in street access to buildings. These results demonstrate that the localization of sustainable development is possible down to the street level at a continental scale and provide a general distributed strategy for accelerating progress in infrastructure and service expansion that taps local innovations in systematic, equitable and context-appropriate ways^7,11,12,15.