Why does urban growth occur?

Urban growth is thought to occur because of the real and perceived benefits of the clustering of human activity (economic and social) in areas of close proximity (Henderson, 2002). Urban centres offer economies of scale in productive enterprises and public investment. Perceived opportunities such as better and more diverse jobs, improved services and the potential for environmental advantage attract people to urban areas (Henderson, 2002; Hildebrand et al., 2013). Urban centres are also social melting pots, centres of innovation and drivers of social change.

However, the speed and scale of urbanisation pose significant challenges: cities are increasingly marked by social differentiation, poverty, conflict and environmental degradation (Beall et al., 2010). Unplanned urban growth may negatively affect economic and social well-being, contributing to congestion, poor housing, pressure on limited public services, air and water pollution (see Topic Guide on Urban Poverty, Urban Pollution and Environmental Management, Satterthwaite, 2015) and associated health issues (Mitlin & Satterthwaite, 2012).

The benefits of agglomeration are also experienced unequally across urban populations. For example, although access to services is higher in urban areas, for those living at or below the poverty line service quality can be poor and costs high. Certain groups, particularly those in informal settlements, may be marginalised in both access to services and decision-making processes (Ducrot et al., 2010; K’Akumu, 2004).