• Editors' Summary
• Credits

1. An Urban Future
• Developing World Urbanizing
2. The Urban Poor
3. Pollution and Health
4. Impact on the Environment
5. Making Urban Areas Work

• Figures
• Tables
• Side-bars
• Bibliography

• Developing countries face fastest urban growth
• Why urban areas are growing
• The poor have greatest health risks
• Heavy ecological footprints
• Improving urban governance
• Assuring water and sanitation
• Mumbai cleans up

• POPLINE
• Media/Materials Clearinghouse
• Other issues
• To order copies
• CCP Home Page

Published by the Population Information Program, Center for Communication Programs, The Johns Hopkins University Bloomberg School of Public Health, 111 Market Place, Suite 310, Baltimore, Maryland 21202, USA

As noted, most of the world’s urban population—like most of the world’s total population—lives in developing countries. In 2000, for example, China had 464 million urban residents, India had 279 million, and Brazil, 138 million—together almost as many as in the entire developed world (131).

With the exception of Latin America, however, the developing world remains much less urban than the developed world. In Latin America, as in the developed world, about 75% of the population lives in urban areas. By 2030 an even greater share, 84%, will be urban, according to projections by the UN. In developing countries as a whole, 40% of the population now lives in urban areas, rising to a projected 56% by 2030. By then every developing region is projected to have an urban majority (131).

Photo: D. Hinrichsen

Shanghai is home to some 13 million people. Together, China, India, and Brazil have about as many urban inhabitants as the entire developed world. In the future, virtually all population increase will be in the urban areas of developing countries.

The level and pace of urbanization will vary substantially among developing regions and countries (131). Over the next 30 years the already urbanized Latin America and Caribbean region is projected to gain only another 217 million urban residents. In contrast, Asia will gain over 1.3 billion (124, 131). India’s urban areas will grow by a projected 297 million residents, Pakistan’s by 86 million, and Bangladesh’s by 64 million (131). By 2030 Africa, with a projected 787 million urban residents, will be second only to Asia’s 2.7 billion in the size of the urban population (see Table 2).

Some researchers contend that urbanization in sub-Saharan Africa has slowed in recent years in response to the region’s depressed economies. In the 1970s and 1980s the gap between rural and urban incomes narrowed or even reversed (26, 38, 58-60). As a result, migration to urban areas declined, and some urban migrants returned to rural areas (91). UN projections for Africa that point to continued urban growth do not reflect these recent economic and demographic trends (92, 105, 114). Whether or not sub-Saharan Africa urbanizes as the UN projects, the region’s depressed economies have severe consequences for its urban areas and residents (137).¹

Explaining urban growth. Settlements expand and become urban for different reasons. The Upper Valley of Rio Negro and Neuquén, Argentina, grew from 5,000 inhabitants to 400,000 between 1900 and 1990, with more than 80% of the population urban, as the area became prosperous from agricultural exports. In contrast, Cuautla, Mexico, grew from a small market town to a city of over 120,000 inhabitants because of tourism (132).

While there are substantial differences in the reasons behind and characteristics of urban growth, overall in developing countries rapid urban population growth reflects three basic factors: (1) migration from rural areas and from other urban areas; (2) natural population increase (births minus deaths) among urban residents; and (3) reclassification of previously rural areas as urban as they become built up and change character. During the initial phases of urbanization in a country, migration from rural to urban areas tends to play a greater role than natural population increase in urban areas. As a greater share of the total population lives in cities, however, natural population increase within them surpasses migration in importance (63, 158). As natural population increase slows, migration can once again play a dominant role in urban population growth—for example, if economic opportunities in urban areas expand rapidly while those in rural areas do not (15).

Because so many people in developing countries are moving from the countryside to urban areas, population growth in rural areas is at a virtual standstill. Among regions, only in Africa and Oceania will rural populations grow at all in the future. In contrast, Asia’s rural population is projected to decrease from an estimated 2,297 million in 2000 to 2,271 million in 2030 (see Table 2). Certain countries in Asia, however, are projected to have continued rural population growth, including Bangladesh, India, Nepal, and Pakistan (131).

People will continue to leave rural areas and move to urban centers to escape adverse rural conditions (push factors). At the same time, many urban areas will continue to attract people from the countryside because they generally offer more opportunity (pull factors).

Factors that push people out of the countryside include the deteriorating quantity and quality of agricultural lands, poor market infrastructures, and lack of supporting institutions, such as sources of credit for small-scale farmers. In Latin America unequal distribution of land—mainly a legacy of colonialism but also due to commercialization of agriculture—has pushed many rural residents into urban areas (63).

John Curley

A mother and child in Mejicanos, El Salvador, visit a dental clinic. Cities attract people from the countryside because they provide more jobs, education, health care, and other services.

Factors that pull residents to some urban areas include access to better jobs, education, health care, and higher living standards. Big cities in particular are economic centers. Bangkok alone, for example, contains only 12% of Thailand’s total population but contributes 38% of the country’s Gross Domestic Product (137).

Most of the world’s largest cities have higher standards of living than smaller urban centers or rural areas, including longer life expectancy and a larger proportion of people with access to piped water, sanitation, schools, and health care (48, 105). Large urban areas have achieved better average living standards mainly because of their economies of scale in providing infrastructure and basic services. High population densities lower the per capita cost of providing clean water, sanitation, waste collection, electricity, and telecommunications (84). For similar reasons, many large cities have succeeded in attracting business investment (105).

As an increasing share of rural-to-urban migrants settle in smaller urban areas—which generally offer lower living standards and fewer opportunities than the big cities—global poverty levels can be expected to rise unless something can be done soon to improve conditions in smaller urban areas. One of the main challenges of urbanization will be to spread the benefits of development from big cities to smaller urban centers, principally through effective decentralization and the transfer of resources and authority from central to local levels. Many smaller urban areas can take advantage of access to important resources, favorable geographic location, and advances in transportation and communication systems to stay competitive with major urban areas in the global economy (68).

¹ Projections of urban growth in sub-Saharan Africa also suffer from the lack of recent and reliable censuses for many countries (92, 105, 114). The UN derives its urban projections for some countries not from current trends but rather from extrapolation of urban growth rates from earlier years for which census data are available. Of the 53 African countries in the UN World Urbanization Prospects 1992 Revision, for example, only 31 had conducted a census since 1980. For the others, urbanization estimates are based on censuses from the 1970s, and from the 1960s for three countries (95).