The recent report from UNICEF "Children in an Urban World" has much to commend it.
Urban populations are growing, more children are being brought up in urban areas, and we in the development research community are having to play catch up with this (based on my highly imperfect knowledge of the number of research projects, research funding streams and calls, journal articles etc.).
The UNICEF report confirms much of what we know: on average urban areas are better off (for example the rates of child underweight prevalences are 1.5 times higher in rural areas), and yet the urban areas contain pockets (large ones) of some of the most destitute and poorest people on the planet.
What the UNICEF report does, being a UN report, is use UN urban population data projections. For example, the inside cover (above) has a graphic that shows Nigeria with 50% of its population living in urban areas.
But a new paper from Deborah Potts at Kings College (in World Development and available here) points out that the UN projections are based on trends in the 60s and 70s when many African countries were rapidly urbanising (that is, their urban populations were growing fast enough to increase the proportion of the population living in urban areas). Once we examine more recent data, we learn that these proportions are way off.
Potts' paper spends much of its time in a forensic analysis of old and new data from Nigeria. She zeros in on an initiative called Africapolis (supported by the French development agency AfD), which cross-references census data, satellite images and secondary data sources (sometimes very very micro) to conclude that 30% of Nigeria's population is urban. And, more extraordinarily, the percentage will only increase to 31% by 2020.
30% versus 50%. And Nigeria is by far the most populous country in Sub-Saharan Africa. This overestimation by UN data trends is constant with new census data emerging from other West African countries, she says.
None of this is to say that urban populations in many African countries are not growing--they are--simply that they may not be growing faster than overall population.
Why has African urbanisation slowed down? Potts' hypothesises that economic growth gains in Africa have not been broadly based in urban areas and that this is slowing rural to urban migration.
Population in African countries might not be urbanising as quickly as conventional wisdom claims, but my guess is that the focus of the development research community still has some urbanising to do.