One factor that is commonly stated about sub-Saharan Africa is that the region is rapidly urbanising, a key structural economic change, which ties in with the idea that the main consumer market is the new emerging urban middle classes.

The reality, however, may well prove to be much more complicated. According to UN and Habitat data, which is by far the most widely cited, sub-Saharan Africa is rapidly urbanising and on course to become a predominantly urban continent at some point in the not too distant future.

But recent research, focused initially in West Africa, but now also in East Africa, casts some doubt on these conclusions. Using a detailed analysis of population censuses and comparing it to satellite pictures and observations on the ground of urban growth, the Africapolis* project argues that the rate of urbanisation is being heavily overstated in this official data.

This does not mean that urban growth is not happening in sub-Saharan Africa – cities are still growing. But overall, and crucially, the percentage of population living in urban areas – the definition of urbanisation – is not rising significantly and the percentage of the population living in urban areas in sub-Saharan Africa may currently be significantly overstated.

While perhaps initially surprising, on reflection this is perhaps not all that out of kilter with the overall sub-Saharan Africa growth story. Although rural-urban migration is a complicated phenomenon and in sub-Saharan Africa is often circular, it still tends to be a highly economically logical action. Potential migrants identify jobs in cities, often through relatives and other contacts from their own village or tribe. These contacts also provide temporary accommodation and support, helping facilitate the move. As a result, migrants also generally move to secure a higher income than they could earn in a rural occupation. But, if large numbers of jobs are not being created, notably manufacturing jobs which are the traditional entry point for most migrants, then the move to an urban area is simply less attractive.

The growth and urbanisation story may also help explain the nature of urban growth in sub-Saharan Africa. Urban centres are growing, but mainly through urban sprawl and often resulting in the hollowing out of traditional city centres. Moreover, much of this growth is low-rise urbanisation rather than an increase in urban population density. In some ways, this may reflect the lack of real land pressures in sub-Saharan Africa, but may just as much reflect a pattern of growth where existing residents identify new areas to settle and move on to them, rather than growth being driven by large inflows of migrants into existing urban areas. The lack of formal manufacturing jobs also drives informal urban economic activity. While much of this is petty trading, there is also a considerable component that is peri-urban agriculture. In effect, these can also be seen as urban survival strategies, rather than a strong motor of growth, although the pattern does still support the overall growth story.

What are the economic implications of stagnating urbanisation? First, the demographic dividend assumes that female fertility rates fall quite sharply as the population urbanises. This may be less of a plausible assumption if a larger percentage of the population is still rural. Second, corporate strategies focused on meeting strongly rising urban demand may well miss a hugely important growth market in the African context – rural consumers. In fact, the similarities between rural and urban markets may be far less pronounced than automatically assumed.

* The Africapolis research, while very comprehensive, seems to have been very much under the radar, but was highlighted by a paper by Deborah Potts for the African Research Institute, Whatever happened to Africa’s Rapid Urbanisation?, which uses the Africapolis research plus some of her own.

David Cowan is currently managing director at Citi and the economist responsible for the bank’s economic research on Africa. This article was first published in a report titled Sub-Saharan Africa: The route to transformative growth.