Urban Africa by numbers By EDWARD PAICE | Thursday, October 13  2011 at  14:23

People and traffic in downtown Lagos, Nigeria. FILE | AFRICA REVIEW 

Everyone knows that Nairobi’s Kibera is the largest “informal settlement”, or slum, in sub-Saharan Africa. At least, they used to know.

Politicians, journalists, NGOs and urban planning professionals routinely declared that 700,000 - 1,000,000 people lived in Kibera. But when the district was geo-statistically mapped for the first time in 2009, its population was estimated at no more than 220,000-250,000.

Kibera has not exactly disappeared, but it is a shadow of its former imagined self.

In similar vein, the city of Lagos is widely believed to have about 15 million inhabitants – an estimate supported by the city authorities in the wake of Nigeria’s contested (and manipulated) 2006 census. But the 2009 Africapolis survey of West Africa’s urban population, the most sophisticated to date and compiled with the aid of satellite imagery, found that the city was home to no more than 10 million people.

Even more significantly, while Nigeria’s census claimed that the country’s population was 140 million, the Africapolis team concluded that “in reality, [Nigeria] probably does not contain 100 million”.

The shrinkage of Kibera, Lagos and Nigeria will prove to be unexceptional. Governments and city authorities competing for funds, and donors and investors competing for projects, have shared a penchant for exaggeration.

Despite the lack of a census in DRC since 1984, McKinsey forecasts that Kinshasa will be the 13th largest city in the world by 2025. The UN has routinely – and demonstrably – over-estimated the size of Africa’s larger cities and urban populations.

Urbanising faster

Over time, errors and misinterpretations of data have become magnified, and projections less realistic. Yet it is the UN’s statistics which are most commonly cited. “They have become ‘fact’ by being constantly re-stated”, says Dr Debby Potts at King’s College, London, “instead of being recognised as guesses”.

More reliable urban population estimates and projections are increasingly available to anyone minded to heed them. They present a far from uniform picture for the continent, but challenge the received wisdom that Africa is urbanising faster than any other continent in the world.

According to Africapolis, the urbanisation level in West Africa will rise by less than 3 per cent, to 34.6 per cent of the total population, in the period 2000-2020. Analysis by Debby Potts and other leading specialists of the 18 censuses published by sub-Saharan countries in the past decade reveals a similar picture.

While urban populations are growing fast in many countries, only in four is rapid urbanisation occurring. According to Potts, “the most common pattern is for slow urbanisation”.

Rapid urbanisation is being portrayed – by the UN, the World Bank and many others – as a potential developmental “silver bullet” for Africa. Cities, we are frequently told, will be the drivers of economic growth and poverty reduction on the continent in the years to come. At present, such claims are too simplistic, and counter-productively over-optimistic.

One of the explanations for the modest momentum of urbanisation in so many African countries is the dearth of opportunities for individuals to improve their lot in towns and cities. Job creation, or lack of it, is the key factor here.

Rural migrants

In the absence of formal or informal employment, or better services, many rural migrants chose to return whence they came, or to come and go – a phenomenon known as “circular migration”.

This is becoming more and more common, and stays in each location are of shorter duration. Natural increase among the poorest urban-dwellers, not migration, is the biggest driver of urban growth in Africa. This means slum growth, and burgeoning ranks of unoccupied young men and women.

As Prof Edgar Pieterse, Director of the African Centre for Cities in Cape Town, points out “this is tough stuff”. In Africa, despite encouraging GDP growth figures over the past decade, larger concentrations of people are not automatically generating benefits – quite the opposite. Talk of widespread “bottom-up development” occurring in towns and cities is far-fetched.

The notion that big ticket urban infrastructure projects will be a panacea is equally misguided.

The social, economic and political consequences of policymakers continuing to ignore the best available demographic research could be grim. For example, appropriate food supply networks and health services require sound knowledge of population distribution and migration patterns.

But unsound “common knowledge” is contributing to bad policymaking and wasted resources – human and financial. “A set of very pernicious trends is unfolding and planned investments will exacerbate these trends”, says Prof Pieterse.

Edward Paice is the Director of the Africa Research Institute (ARI)