The evidence from censuses and satellite imagery is increasing that the rate at which many countries are becoming more urban in sub-Saharan Africa has slowed or is even stagnating. This has major policy implications. Many standard reviews of the region still, however, tend to maintain that urbanization is occurring rapidly but, as this paper demonstrates, the data used are frequently erroneous. Such errors are exacerbated by a lack of reasonable estimates of the size and growth of towns in Nigeria, sub-Saharan Africa’s most populous country with the region’s most complex urban system. This paper also attempts to address this knowledge gap and shows how Nigeria’s level of urbanization has also been significantly over-estimated.

That was from Deborah Potts’ new paper in World Development (ungated version here). Taking the example of Nigeria, the paper shows that the country’s major urban centers were stagnating or losing population relative to the country as a whole. Why is that happening?

The primary cause of reductions in urban population growth in Africa is the weak performance of African urban economies and the very high levels of economic insecurity this means for the vast majority of urban people

… There is also a wealth of evidence on the declines suffered by productive enterprises in cities due to foreign competition. Another severe problem is the very unreliable urban electricity supply throughout the country, meaning many enterprises have to use expensive generators, further undermining their competitiveness

And from the conclusions:

In 2004, Cohen suggested that, ‘[g]iven the historical connection between industrialization and urbanization, continued urbanization in Africa may only be possible if there is a sharp increase in economic development’ (Cohen 2004: 48). This appears to have been a rather better prediction about African urbanization than many, more recent ones. There is evidence now from many sub-Saharan African countries of slowing or stagnating urbanization, defined in terms of a relative increase in the urban versus the rural population