LSE’s Sean Fox argues that some basic misunderstandings about the nature and causes of  Africa’s urban transition have resulted in decades of misguided development policies in the region.

The urban population of sub-Saharan Africa is growing at an astonishing pace. Today approximately 325 million people live in urban settlements in the region. According to UN projections, that number will triple in the next few decades, reaching over 1 billion by 2050.

Such intense demographic pressure in urban areas has been a source of justifiable concern for African governments and international observers for decades. Today, approximately 60% of the region’s urban population live in slums, urban poverty is rising rapidly despite recent gains in rural poverty reduction, African countries suffer from some of the highest homicide rates in the world, and there is some evidence that ‘urban social disorder events’ (eg riots, strikes, protests and acts of terrorism) have risen in recent years.

However, these outcomes are not inevitable consequences of Africa’s urban transition. Indeed, more urbanised societies are generally healthier, wealthier, less violent and more democratic than less urbanised ones. With the appropriate policies and strategies in place, Africa’s urban transition could transform the development prospects of countries across the region. Unfortunately, African governments and international development organisations have been getting it wrong for decades.

Since the mid-1970s, African governments have increasingly adopted policies designed to inhibit or discourage people from moving into urban areas. Today, approximately 80% of African countries have policies in place to prevent rural-urban migration. At the same time, international development organisations increasingly withdrew support for urban development initiatives in favour of rural development projects, often justified by the argument (among others) that improving standards of living in rural areas will help to mitigate the growth of urban poverty. These trends in development policy have been driven, at least in part, by two key misconceptions about the nature and causes of Africa’s urban transition.

The first (pervasive) misconception is that Africa  is urbanising exceptionally fast due to intensive rural-urban migration. This is simply not true. Africa’s rate of urbanisation (i.e. change in the percentage of Africans living in urban as opposed to rural areas) is far lower than that of East Asia, for example, and not unusually rapid by historical standards. However, what is true is that Africa’s urban population has been growing at an historically unprecedented rate for decades. It is important from a policy perspective to appreciate this distinction between rates of urbanisation and rates of urban population growth. Most policy makers don’t.

The reason they don’t is due to the second (equally pervasive) misconception, which relates to our traditional theoretical understanding of the driving forces behind urbanisation and urban growth.

In 1954, LSE alumnus Sir Arthur Lewis published one of the first and most influential theories in the history of development economics in an article entitled ‘Economic Development with Unlimited Supplies of Labour’. Informed by the history of European industrialisation, the ‘Lewis model’ portrayed urbanisation as a natural by-product of rural-urban migration (the proximate cause of urbanisation) stimulated by economic development. It is an elegant, intuitive and still-influential idea. But it is only half true. The growth of waged employment opportunities in urban areas that accompanies industrialisation can certainly spur rural-urban migration, and hence urbanisation. It is not, however, a necessary condition for urbanisation to occur.

From the mid-1970s through the 1990s, the economies of countries across sub-Saharan Africa stagnated. Per capita GDP actually fell in many cases and there was little change in the sectorial composition of output (an indicator of structural economic development) in the region. And yet urbanisation persisted and urban population growth remained exceptionally rapid—a widely noted yet inadequately explained phenomenon dubbed ‘over-urbanisation’ or ‘urbanisation without growth’ (see Table 1). It is this phenomenon which has led economists and policy makers to conclude that Africa’s urban transition has deviated from an ideal development trajectory and that measures should therefore be put in place to discourage rural-urban migration in order to maximise social welfare (and avoid the spectre of social and political unrest in urban areas).

In fact, there is nothing particularly unusual about the dynamics of Africa’s urban transition once the true underlying forces driving the process are understood.

Economists have assumed for decades that individuals decide to move from rural to urban areas primarily in the hope of getting a job. It follows that the prospect of getting a job (i.e. economic conditions) should correlate with urbanisation. Empirical research has provided very tenuous evidence in support of such a link. Why?

A wealth of anthropological and sociological studies have shown that people also choose to migrate for a variety of non-economic reasons, including a desire to escape age or gender discrimination in their communities, to find a wife or husband, to seek adventure in the “bright lights” of the big city, or to escape rural serfdom. In medieval Germany, there was a saying that “city air makes you free”. As a result, migration trends are far less sensitive to economic trends than the traditional model of urbanisation predicts. In other words, there are always individuals who have a reason to migrate to cities regardless of prevailing economic circumstances. It is therefore no surprise that rural-urban migration (and hence urbanisation) persists in the face of economic stagnation.

But this does not explain the exceptional rates of urban population growth seen across Africa. As noted above, rates of urbanisation (driven by rural-urban migration) in the region are not particularly rapid. So where are all these people coming from? The answer is that the majority of Africa’s expanding urban population are born in cities, not in villages.

To make a long story short, there have been significant improvements in life expectancy in urban and rural areas across Africa since the 1940s as a result of technological and institutional changes that have reduced disease-related mortality and improved food security. Due to persistently high fertility rates, this has led to a population boom of historically unprecedented proportions. While this may be contributing to rural out-migration due to population pressure in rural areas, it is also driving rapid population growth in urban areas that is wholly independent of migration. Simply put, the rapid growth of Africa’s urban population is being driven primarily by rapid population growth in urban areas, not rural-urban migration (see Table 1).

From a practical perspective, the pressing challenges of providing adequate housing, infrastructure, employment opportunities and security in African cities relate to rapid urban population growth, not urbanisation. And yet governments and aid agencies have mistakenly sought to deal with these challenges by targeting rural-urban migration based on a misunderstanding of the dynamics shaping Africa’s urban transition. For those interested in easing demographic pressure in urban areas, the only humane policy option is to try to reduce population growth by promoting fertility decline through voluntary family planning initiatives. And for those interested in promoting economic development in the region, investment in urban areas should be top of the policy agenda.

Read Sean Fox’s working paper, Understanding the Origins and Pace of Africa’s Urban Transition.



Beall, J. and Fox, S. (2009). Cities and Development.London: Routledge.

Fox, S. (2011) ‘Understanding the Origins and Pace of Africa’s Urban Transition’, Crisis States Working Paper No. 89 (Series 2), Crisis States Research Centre, London School of Economics and Political Science. Available at:

Fay, Marianne and Charlotte Opal (2000) Urbanization without growth: A not so uncommon phenomenon, Policy Research Working Paper no. 2412,WashingtonD.C.: The World Bank.

Fox, S. and Hoelscher, K. (2012). ‘Political order, development and social violence’, Journal of Peace Research, Vol. 49 (3).

Lewis, Arthur (1954). ‘Economic Development with Unlimited Supplies of Labor’, The Manchester School, Vol. 22: 139–191.

Ravallion, M., Chen, S. and Sangraula, P. (2007). New Evidence on the Urbanization of Global Poverty. Policy Research Working Paper no. 4199.WashingtonD.C.: The World Bank.

Urdal, H. and K. Hoelscher (2009). ‘Urban Youth Bulges and Social Disorder: And Empirical Study of Asian and Sub-Saharan AfricanCities’, Policy Research Working Paper No. 5110,Washington,D.C.: The World Bank.