The Transition to a Predominantly Urban World and its Underpinnings

This paper makes use of the latest set of urban data from the United Nations Population Division and a review of data from recent censuses to describe the scale and nature of urban change. It also discusses the economic, social and political drivers of urbanization, particularly since 1950, and how these have changed. For instance, from the 1950s to the 1980s, the political changes associated with the ending of colonial empires and the achievement of independence had profound influences on the scale and spatial distribution of urban development in most nations in Africa and Asia but in recent decades, economic changes have had greater importance.

The paper suggests that within most nations, the main driver of urban change is best summarized as the geography of where profit-seeking enterprises choose to concentrate (or to avoid). This can be seen in:
- the high concentration of the world’s urban population and its largest cities in the world’s largest economies;
- the strong association between nations’ per capita incomes and levels of urbanization;
- the way that increases in levels of urbanization for most low- and middle-income nations over the last 50 years track increases in the proportion of GDP generated by industry and services and the proportion of the labour force working in industry and services; and
- the fact that it is generally nations with the most rapid economic growth that have urbanized most and generally the nations with the poorest economic performance that have urbanized least.

The paper also highlights a range of myths that are common in much of the general literature about urban change – for instance, overstating the concentration of the world’s urban population in cities and in megacities; the assumption that large cities are growing rapidly (most of the largest cities have slow population growth rates and many have more people moving out than in); exaggerations in the speed of urban change (the world was actually less urbanized and less dominated by large cities in 2000 than had been predicted); and the assumption that the speed of urban change in low- and middle-income nations is unprecedented (many of the world’s fastest-growing cities over the last century are in the USA). The paper discusses how there may be an underlying economic logic to much urban change but the form it takes is powerfully shaped by political and social factors. These also influence the extent to which nations and cities have developed the institutions and legal and fiscal frameworks needed to govern rapid urban change – and address the fact that a high proportion of the urban population live in poor quality, overcrowded housing often in illegal settlements lacking good provision for water, sanitation, drainage, health care and schools.

The paper also discusses how there is no automatic link between rapid urban growth and urban problems. Some of the world’s fastest-growing cities are also among the best governed, with among the best quality of life in their nation. In addition, by concentrating people and enterprises, cities present many opportunities for better services and environmental management. However, the paper also notes the complex and contested processes needed to get “good urban governance” and the extent to which international agencies have failed to understand and support this. Annexes at the end of the paper list the world’s 100 largest cities in 2000, with details of their population growth since 1800, and the world’s fastest-growing and slowest-growing large cities for 1950–2000.