Cities Transformed: Demographic Change and Its Implications in the Developing World (2003)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Cities Transformed: Demographic Change and Its Implications in the Developing World 1 Introduction Flying into S˜ao Paulo on a clear day, one can easily understand why this city has been called the locomotive that pulls the rest of Brazil. With a population in ex- cess of 15 million, it is the largest city of the Southern Hemisphere. From its cen- ter thrust impressive clusters of modern buildings; beyond them the metropolitan complex stretches as far as the eye can see. This is the foremost industrial center of Latin America, and a dominant presence in finance and trade. S˜ao Paulo is home to Brazil’s automobile industry, and accounts for much of its manufacturing in sectors as diverse as computers, electrical and mechanical appliances, chem- icals and pharmaceuticals, textiles, furniture, and processed foods. With about one-tenth of Brazil’s population, the city generates one-third of the country’s net national product. In addition to being an economic powerhouse, S˜ao Paulo is a force in culture and intellectual debate, the site of four universities, a medical school, and many important museums. In economics, politics, and the arts, writes Alves (2003), “S˜ao Paulo has become an exporter of ideas.” This is a bird’s-eye view of the city, but on closer inspection S˜ao Paulo takes on a more variegated appearance. It can be seen that poor neighborhoods and ramshackle housing surround some of the high-rise commercial clusters. Con- sider the situation of Marta, a young woman who lives in one of these favelas. Her husband once held a steady job in a manufacturing firm, but lost it in the eco- nomic downturns of the 1980s and now ekes out a living as a security guard for a rich family. Marta herself takes in work as a seamstress, but she keeps an eye out for any opportunity that might come her way. She is pleased that her daughters are about to complete primary school, unlike their cousins in the countryside who dropped out. Still, she worries incessantly about the children’s safety, especially since their route to school wends through territory claimed by rival gangs. Marta’s aunt, a formidable nurse in a clinic not far away, continually impresses upon her the need for the children to be well educated, but in looking ahead, Marta finds herself wondering whether the girls would really benefit from secondary school. 9 Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World 10 CITIES TRANSFORMED The pros and cons of schooling are much debated among her friends, some point- ing to success stories and others to children who wasted their education; they all complain, however, about the difficulties and costs of rearing children properly in S˜ao Paulo. Marta’s friends are unanimous on one point: to have five or six children today, as was often done in their mothers’ time, would be too exhausting even to contemplate. In vignettes such as this, the positive and negative elements of urban life are thoroughly intermixed. Cities are the sites where diverse social and eco- nomic resources are concentrated, and that concentration can generate substantial economic benefits in the form of innovation and income growth (Jacobs, 1969; Glaeser, Kallal, Scheinkman, and Shleifer, 1992; Henderson, 2002). If cities could not offer such benefits, they would have little reason to exist, for the mass- ing of production and population also generates many costs—heavy congestion, high rents, and stress on the capacities of government. In the nineteenth century, this opposition of benefits and costs was well understood. The cities of that time were likened to “satanic mills” where one could seize economic opportunity only at some risk to life and health. In much of today’s popular writing on cities, how- ever, the costs of city life tend to be vividly described, while the economic benefits are left unmentioned. Cities are also the sites of diverse forms of social interaction, whether on the staging grounds of neighborhoods, through personal social networks, or within local community associations. The multiple social worlds inhabited by city res- idents must profoundly influence their outlooks and perceptions of life’s possi- bilities. In city life, many family productive and reproductive strategies are on display, with the consequences being acted out by local role models and reference groups. The poor are often brought into contact with the near-poor and sometimes with the rich; these social collisions can either stir ambitions or fan frustrations. The social embeddedness and multiple contexts of urban life (Granovetter, 1985) would thus appear to present demographic researchers with a very rich field for analysis. Over the past two decades, researchers interested in high-income countries have moved to take up this analytic challenge, with much of the intellectual energy being provided by the powerful writings of Wilson (1987) and Coleman (1988, 1990) on the roles of neighborhoods and local context in the cities of the United States. But the cities of poor countries have seen no comparable surge in demo- graphic research. Indeed, apart from the occasional study of migration, the main- stream literature has been all but silent on the demographic implications of urban life in developing countries. Not since Preston (1979) and the United Nations (1980) has there been a rigorous, comprehensive assessment of urban demogra- phy in these countries. As we will discuss, the U.S. literature has emphasized many of the themes that are of central importance to the cities of low-income countries: children’s schooling, reproductive behavior among adolescents and adults, health, spatial Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World INTRODUCTION 11 segregation, and employment. It has also advanced important theories and mecha- nisms—social learning, networks, collective socialization, and social capital among them—that have clear parallels in developing-country cities. Yet, at least to date, the theories and research strategies being vigorously pursued in the U.S. context have not been taken up elsewhere. On these grounds alone, a review of what is known about urban population dynamics would appear well overdue. This chapter introduces some of the themes that will be explored in the chap- ters to follow, together with basic demographic information on the urban trans- formation. The chapter also describes the panel’s charge, the main reasons for undertaking this study, and some of the major audiences for the report, with par- ticular reference to the demographic research community. THE DEMOGRAPHIC TRANSFORMATION The neglect of urban research can only be reckoned astonishing when considered in light of the demographic transformations now under way. The world’s popu- lation passed 6 billion in 1999, and 6 of every 7 people now reside in a low- or middle-income country.1 The global rate of population growth has declined over the past 20 years; in absolute terms, however, the world remains in the midst of an era of historically dramatic population increase. According to the latest United Nations (2002a) projections, even as the rate of population growth continues to decline, the world’s total population will rise substantially. The total is expected to reach 8.27 billion in 2030, this being a net addition of 2.2 billion persons to the 2000 population. Almost all of this growth will take place in the poor countries of the world, whose governments and economies are generally ill equipped to deal with it. The Urban Future As Figure 1-1 shows, over the next 30 years it is the world’s cities that are expected to absorb these additional billions.2 The total rural population is likely to undergo little net change over the period, declining by 30 percent in high-income coun- tries and increasing by an expected 3 percent in low- and middle-income coun- tries. Relatively small changes are also expected for the cities of high-income 1 In this report we take as synonymous the phrases low- and middle-income countries, poor coun- tries, and developing countries, although we recognize that they differ in emphasis and shades of meaning. We follow the World Bank (2002b) in classifying a country as high-income if its gross na- tional income per capita in the year 2000 exceeded $9,266 in the World Bank’s estimation. We also take the terms urban areas, cities, and cities and towns to be broadly synonymous, often employing the last of these to highlight the great size range of urban places. 2 The great variety of definitions of “urban” used by national statistical agencies and deficiencies in the measures these agencies supply to the United Nations imply that the United Nations estimates and projections can be taken only as broadly indicative of levels and trends. Definitional and measurement issues are discussed at length in this report. Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World 12 CITIES TRANSFORMED 5,000 4,000 Urban Rural Population (in millions) 3,000 2,000 1,000 0 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030 Year FIGURE 1-1 Estimated and projected urban and rural populations, world totals 1950–2030. SOURCE: United Nations (2002a). countries, whose populations will rise from 0.9 billion in 2000 to 1 billion in 2030. Hence, as can be seen in Figures 1-2 and 1-3, the net additions to the world’s population will be found mainly in the cities and towns of poor countries. The prospects for the near future stand in stark contrast to what was seen during the period 1950 to 1975, when population growth was much more evenly divided between urban and rural areas. The United Nations predicts that the total urban populations of Africa, Asia, and Latin America will double in size over the next 30 years, increasing from 1.9 billion in 2000 to 3.9 billion in 2030. These changes in totals will also be reflected in the urban percentages. In 1950 less than 20 percent of the population of poor countries lived in cities and towns. By 2030, that figure will have risen to nearly 60 percent. Rather soon, it appears, it will no longer be possible to speak of the developing world as being mainly rural. Both poverty and opportunity are assuming an urban character. Each of the developing regions is expected to participate in this trend. As Figure 1-4 shows, a good deal of convergence is anticipated, but considerable dif- ferences will likely remain in levels of urbanization (the percentage of the popula- tion residing in urban areas) by geographic region. Latin America is now highly urbanized: 75 percent of its population resides in cities, a figure rivaling the per- centages of Europe and North America. Africa and Asia are much less urbanized, Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World INTRODUCTION 13 Rural, All Countries Urban, Low- and Middle-Income Urban, High Income 2,000 Total Population Growth (in millions) 1,500 1,000 500 0 1950–1975 1975–2000 2000–2030 Time Span FIGURE 1-2 Distribution of world population growth by urban/rural and national income level. Estimates and projections for 1950–2030. SOURCE: United Nations (2002a). 4,000 High-Income Countries Total Urban Population (in millions) Low- and Middle-Income Countries 3,000 2,000 1,000 0 1950 1960 1970 1980 1990 2000 2010 2020 2030 1955 1965 1975 1985 1995 2005 2015 2025 Year FIGURE 1-3 Growth of total urban population by national income level, 1950– 2030. SOURCES: United Nations (2002a); World Bank (2001). Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World 14 CITIES TRANSFORMED 1950 80 1975 2000 2030 60 Percentage Urban 40 20 0 World Africa Asia Latin Europe North Oceania America America Region FIGURE 1-4 Estimated and projected percentage of population in urban areas, by region, 1950–2030. SOURCE: United Nations (2002a). however, with less than 40 percent of their populations being urban. However, Asia will contribute the greatest absolute number of new urban residents over the next three decades. Although both Africa and Asia will become more urban than rural in the near future, they are not thought likely to attain the 60 percent level before 2030. A Future of Megacities? In popular writing on the cities of developing countries, it is the largest cities that receive the most attention. Perhaps it is only natural that cities the size of S˜ao Paulo, Bangkok, Lagos, and Cairo come readily to mind when urban populations are considered. Yet for the foreseeable future, the majority of urban residents will reside in much smaller settlements, that is, in small cities with 100,000 to 250,000 residents and in towns with populations of less than 100,000. Data on these cities and towns are scarce and grossly inadequate. No comprehensive, re- liable, and up-to-date database exists for cities under 100,000 in population, and as is discussed later, it is even difficult to find data in a usable form for cities under 750,000. Despite these difficulties, some information on urban populations by size of city can be gleaned from the United Nations (2002a). Figure 1-5 presents the United Nations predictions, showing the number of urban residents who will be Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World INTRODUCTION 15 500 400 Additional Urban Population (in millions) High-Income Countries Low- and Middle-Income Countries 300 200 100 0 <1 1–5 6–10 10+ City Size (in millions) FIGURE 1-5 Net additions to urban population, by city size and national income level, 2000–2015. SOURCES: United Nations (2002a); World Bank (2001). added to cities of different sizes over the period 2000 to 2015. As can be seen, the lion’s share of the increase will be taken by towns and cities with fewer than 1 million inhabitants. Figure 1-6 depicts the projected distribution (in 2015) of urban population by size of city. Towns and cities with a population of under 1 million will then account for about 60 percent of the developing-country urban total. Cities from 1 to 5 million in size will house another 26 percent. As a rule, smaller cities tend to grow more rapidly than do larger ones. This tendency is evident in regression analyses with controls for confounding factors, and in the trajectories followed by individual cities over time. To be sure, there is considerable unexplained variation in the relationship between city size and growth. Nevertheless, as will be discussed later, the negative association between the two is sufficiently robust for the United Nations to have incorporated the rela- tion in its forecasting methods. We cannot recall a case in which a small city was the focus of an edito- rial lamenting rapid urban growth or the lack of public services. Nevertheless, the combined size of such cities makes them very significant presences in de- veloping countries. As is shown throughout this report, smaller urban areas— especially those under 100,000 in population—are notably underserved by their governments, often lacking piped water, adequate waste disposal, and electricity. Indeed, they can exhibit levels of human capital, fertility, health, and child sur- vival that are akin to those found in rural areas. The sheer scale of the challenges Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World 16 CITIES TRANSFORMED 60 High-Income Countries Percentage of Urban Population Low- and Middle-Income Countries 40 20 0 <1 1–5 6–10 10+ City Size (in millions) FIGURE 1-6 Projected distribution of urban residents in 2015 by city size for high-income countries, and for low- and middle-income countries. SOURCES: United Nations (2002b); World Bank (2001). presented by very large cities should not cause the difficulties of these small cities to be overlooked. We are by no means suggesting that large cities be neglected in policy and research. The scale on which resources are concentrated in these cities presents governments with needs that are of a qualitatively different order than those of small cities and towns. At the beginning of the twentieth century, there were only 16 cities in the world with populations of 1 million or more, and the vast majority of these cities were found in advanced industrial economies. Today the world contains more than 400 cities of this size, and three-quarters of them are found in low- and middle-income countries. For the residents of these cities, scale is a defining feature of social, economic, and political life. It has many positive aspects: when urban activity is appropriately organized and governed, scale can enable specialization, reduce the per capita costs of service provision, and allow economic and social diversity to flourish. In poor countries, however, which lack all manner of the necessary administrative and technical resources, the challenges presented by large cities can be daunting indeed. In these countries, the proportion of the population residing in large cities is approaching the levels seen in rich countries. In 2000, about one-third of the national populations of rich countries lived in cities of at least 1 million residents. Although poor countries have not yet reached the one-third mark, they are moving toward it. In 1975, only 9 percent of the national populations of poor countries Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World INTRODUCTION 17 lived in such cities. By 2000, the total had risen to 15 percent, and it is expected to rise further, to 17 percent, by 2015. THE TRANSFORMATION OF CITIES S˜ao Paulo, now Latin America’s second-largest city and a megacity by any def- inition, had its origins as a minor commercial center. Although the story of S˜ao Paulo has unique elements, it can stand as an example of the changes under way in cities worldwide. In 1890, when Rio de Janeiro could boast a population of more than half a million, only 65,000 people lived in S˜ao Paulo. It was improvements in agriculture—widespread coffee cultivation in the region—that ushered in S˜ao Paulo’s first era of prosperity. By the early 1900s, manufacturing had gained a foothold in the city, mainly in connection with the processing and marketing of coffee. Over the next half-century, industrialization began on a large scale, a de- velopment spurred by the collapse of world prices for coffee, which caused large landowners and major entrepreneurs to scramble for ways to diversify. By 1950 S˜ao Paulo had assumed its present position as the leading manufacturing center of Brazil. Industrialization then further accelerated, encouraged by the government’s strategy of import substitution and the construction of a transportation system that made the city a central node. The city’s rate of population growth in this era was truly spectacular—in the 1950s, S˜ao Paulo was one of the world’s fastest-growing metropolitan areas. Although its growth rate subsequently declined, the popula- tion of the greater S˜ao Paulo metropolitan area is still increasing and is expected to exceed 20 million by 2015 (United Nations, 2001). In this history are found several of the themes with which this report is concerned—the linkages of cities to their surrounding regions, the role of world markets, government development strategies and investments, and demographic transitions. In what follows we describe more systematically the principal themes that link the chapters of this volume. Space and Measurement As countries urbanize and proportionately more of their citizens find homes in cities, the need grows for spatially disaggregated data on the conditions of urban life. It is difficult to imagine how cities can be governed effectively without such data. But from what sources are spatially disaggregated data now available? Na- tional censuses can provide useful measures for small spatial units, but censuses are not often examined at such disaggregated levels. Few national surveys have samples sufficiently large to permit estimation at fine-grained spatial resolutions. To fill the gap, some countries have been making use of remotely sensed data and other measures organized in geographic information systems (GIS). Such spatial detail could, in theory, provide a stronger basis for forecasts of city populations than now exists. We suspect, however, that the greatest value of Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World 18 CITIES TRANSFORMED QuerÈtaro HIDALGO Pachuca PUEBLA STATE OF TLAXCALA MEXICO Tlaxcala T Puebla Federal District Megalopolis Cuautla Urban subsystem MORELOS FIGURE 1-7 Mexico City urban subsystem, 1995. SOURCE: Garza (2000), reprinted with permission. spatially disaggregated data will lie in their potential to spark dialogue among ur- ban units of government and groups of citizens. In Cape Town, South Africa, the metropolitan government is now displaying data drawn from a GIS on its Inter- net Web site, where residents can easily see how the provision of water and other services in their neighborhoods compares with that elsewhere in the city (for dis- cussion, see Milne, 2001). This new technology has opened a channel through which poor groups might one day press government officials for greater equity in the provision of resources. Spatial disaggregation may also enable progress to be made on a problem that has long bedeviled urban studies—how to define and measure the extent of a city. These measurement concerns are addressed later in the report, but to appreciate their implications, it may be useful to consider two examples here. The extent of Mexico City is for some purposes defined to be the Federal Dis- trict (Distrito Federal); for other purposes it takes in the Mexico City Metropolitan Area; and for still others it encompasses the large urban megalopolis centered on Mexico City but including the population of Toluca (see Figure 1-7). In the 2000 census, the population of the Federal District was estimated at 8.6 million, and that of the larger Mexico City Metropolitan Area at 17.9 million. The urban megalopo- lis was estimated to contain 19.1 million residents.3 Evidently, one’s choice of city definition can double or halve the reported city population and wholly reconfigure its socioeconomic profile. 3 A still more expansive conception would acknowledge the system of cities in which Mexico City participates, including Toluca, Puebla, Cuernavaca, Quer´etaro, and Pachuca, among which the flows of people, goods, and services are considerable. This polynuclear metropolitan region (or megalopolis) had a population of 23.2 million inhabitants in 2000, representing 24 percent of Mexico’s total national population and 35 percent of its total urban population (Garza, 2000). Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World INTRODUCTION 19 TABLE 1-1 Comparison of Two Estimates of Population Size and Growth in Four Extended Metropolitan Regions (EMRs) Bangkok Jakarta Manila Taipei 1980 1990 1980 1990 1980 1990 1980 1990 Population Urban 4,723 5,901 5,985 7,650 5,955 7,968 2,217 2,711 Agglomeration Core 4,697 5,876 6,481 8,223 5,926 7,948 2,268 2,761 Inner Zone 1,947 2,706 5,413 7,676 2,820 4,107 3,070 4,035 Outer Zone 2,513 3,061 n.a. n.a. 2,932 3,908 709 757 Whole EMR 9,157 11,643 11,894 15,899 11,678 15,963 6,047 7,553 1980–1990 Rate of Growth Urban 2.22 2.45 2.91 2.01 Agglomeration Core 2.23 2.38 2.93 1.96 Inner Zone 3.29 3.49 3.75 2.73 Outer Zone 1.97 n.a. 2.87 0.65 Whole EMR 2.40 2.90 3.12 2.22 NOTE: n.a. means not available. SOURCES: Data on urban agglomeration from United Nations (2001); all other data from Jones (2002). The benefits of disaggregating data in spatial dimensions can also be seen by considering four large metropolitan areas in Southeast Asia—Bangkok, Jakarta, Manila, and Taipei. Just how large are these large cities? How rapidly are they growing? Again the answers depend on how boundaries are drawn. Table 1-1 shows the urban agglomeration population estimates supplied by the United Na- tions (2001) and compares them with more spatially refined estimates that dis- tinguish among a city core, an inner zone of settlement, and an outer zone (from Jones, 2002). The core, inner, and outer zones together constitute an extended metropolitan region. If the extended region is taken to be the appropriate mea- sure, the United Nations estimates of city population size are understated by half (Jones, 2002). In addition, rates of population growth differ a good deal among the core, inner, and outer zones, with the inner zones growing much more rapidly than the official urban agglomeration. If the city boundaries are drawn too tightly, important developments may be missed in the periurban areas lying just outside these boundaries (Jones, Tsay, and Bajracharya, 2000). Socioeconomic Diversity Within Cities Social, economic, and spatial diversity is a fact of life in cities, whether of the size of S˜ao Paulo or smaller. Almost all cities contain elite neighborhoods that are well served by schools, health facilities, and public utilities. Likewise, almost all contain desperately poor neighborhoods whose residents live in dilapidated Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World 20 CITIES TRANSFORMED housing and suffer from inadequate public services. In many countries in the developing world, at least one urban resident in four is thought to be living in absolute poverty (Hall and Pfeiffer, 2000). In the world’s poorest countries, the conditions of life in slums and shantytowns can be extremely grim. Rural migrants to cities add another element of diversity; in many accounts they are said to be further swelling the slums. A central theme of this report is the need to attend to the spatial aspects of diversity and inequality. As a country urbanizes, one naturally expects its cities to house a growing percentage of all poor citizens. To understand urban poverty, it is necessary to understand where within cities the poor live and to map the condi- tions of their neighborhoods. The analysis entails a study of spatial segregation, local social networks and social capital, and the localized features of government. Of course, not all urban inequality will be expressed spatially. As Caldeira (1999, 2000) reminds us for S˜ao Paulo, by establishing fortified enclaves the rich can quite effectively exclude the poor without putting them at any great distance. But the spatial aspects of segregation warrant close attention, not least because gov- ernments and nongovernmental organizations (NGOs) must often operate on a territorial basis. Another aspect of urban diversity is more beneficial, or at least potentially so. Following the lead of Jacobs (1969), economists have been exploring the ways in which the diversity of economic activity in cities can stimulate innovation and pro- ductivity growth. At present, much of this literature is theoretical, but empirical studies are beginning to appear (e.g., Glaeser, Kallal, Scheinkman, and Shleifer, 1992; Moretti, 2000; Duranton and Puga, 2001; Henderson, Lee, and Lee, 2001; Henderson, 2002). These diversity effects are a form of what are termed “ag- glomeration economies,” a phrase that refers to the productivity advantages stem- ming from the spatial concentration of production. The social theories mentioned earlier—concerning social learning and networks, reference groups, collective so- cialization, and the like—also emphasize the potential benefits of diversity, and in this respect closely parallel the economic theories. Space figures centrally in urban economic and social theory because proximity facilitates the gathering and exchange of information, lessens the costs of transport, and makes possible the exercise of some beneficial social controls. Fertility and Reproductive Health For developing countries there are surprisingly few careful studies of inter- and intraurban differentials in fertility and reproductive health. As is well known, urban residents face many constraints and opportunities that influence their child- bearing. They typically want fewer children than their rural counterparts, making the general level of demand for contraceptive services higher in urban than in rural areas. Urban couples are probably more apt to appreciate the advantages of hav- ing fewer but better-educated children, choosing to make greater investments in Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World INTRODUCTION 21 their children’s schooling and adopting childrearing strategies that place heavier demands on parental time. What is it about urban environments that encourages such reproductive strategies? The fertility implications of urban contexts were once prominent in demo- graphic transition theory, a collection of ideas about demographic change that Van de Kaa (1996), Kirk (1996), and Mason (1997) have recently reappraised. In- deed, Notestein (1953) went so far as to suggest that urbanization be considered as something of a precondition for fertility decline. The historical record shows that fertility was lower in urban than in rural areas in many historical populations, al- though debate persists on the relationship of urbanization to fertility decline. The Princeton European Fertility Project examined marital fertility in Europe during the nineteenth and twentieth centuries, and found urban fertility to be lower than rural in almost every region and time period. Fertility was also found to be lower in larger than in smaller cities (Sharlin, 1986). A detailed study by Galloway, Hammel, and Lee (1994) for Prussia makes a strong case that here, urbanization was linked to fertility decline, in the sense that measures closely associated with urbanization (percentages of the adult population employed in banking, insurance, and communication) were found to have exerted substantial influence on the pace of fertility decline.4 In what ways might fertility behavior be distinctively urban? Broadly speak- ing, the distinctive features have to do with the benefits of new family reproductive strategies, the costs of executing these strategies, and the features of urban social life that shape the perception of benefits and costs. In considering whether to have fewer children, urban parents may well be influenced by the consequences they can observe in their own social networks and neighborhoods. If these net- works and neighborhoods are homogeneous, they may not provide a sample of experience with sufficient range to demonstrate the implications of innovative re- productive decisions. In cities, however, local networks and information are likely to be more diverse than in the countryside, and this diversity can enrich the infor- mation available to parents and give them the necessary confidence to take innova- tive actions. The mechanisms are those highlighted in multilevel theories of social learning and diffusion (National Research Council, 2001). By limiting the variety of social role models and reference groups on view, the spatial segregation of the urban poor may have the effect of increasing uncertainties about new strategies, thereby prolonging dependence on traditional strategies of high fertility. The costs of obtaining family planning, health, and related services also have an urban aspect. Certainly the private health sector is far more prominent in cities. 4 These authors examined Prussian Kreise—small administrative units—using fixed-effect regres- sion methods. In addition to the banking, insurance, and communication measures, they included the urbanization level of each Kreise, but uncovered no additional effects of interest. Of course, there remains room for debate about the strength of the connection elsewhere in historical Europe. Other empirical studies of the European experience have not found a close connection between urbanization and fertility decline (Lesthaeghe, 1977; Coale and Watkins, 1986). Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World 22 CITIES TRANSFORMED It is itself highly diverse and heterogenous. In large cities, one finds sophisticated clinics and teaching hospitals that cater to the elite operating alongside an assort- ment of pharmacists and traditional healers. The physical distance to services is no doubt less in many cities than in rural areas, but whether urban services are of any higher quality once reached is highly debatable. As will be seen, the few careful comparisons that have been made between urban and rural services show the supposed urban advantage to have been much overstated, especially where the urban poor are concerned. Many other features of social life in the city can have important reproduc- tive health implications. In some cases, urban settings present young unmarried women with completely new behavioral options. The establishment of a garment manufacturing sector in Dhaka, for example, has created the opportunity for un- married women to work outside the home in direct contact with men, a situation al- most unimaginable a generation ago (Amin, Diamond, Haved, and Newby, 1998). This experience is likely to transform the attitudes and social confidence of young women, influencing the terms upon which they enter marriage, engage in child- bearing, and make decisions about their children’s schooling. Men and women in urban areas tend to marry later than their rural counterparts, and therefore appear more likely to have transitory partnerships and (perhaps) to begin sexual activity prior to marriage. Early and unprotected adolescent sex is a familiar urban con- cern. Cities also contain disproportionately more young migrants, many of whom have postponed marriage or engage in extramarital sex. Urban areas usually have higher levels of prostitution than rural areas and have exhibited greater prevalence of HIV/AIDS and other sexually transmitted diseases. Health Urban inequalities are perhaps most vividly expressed in measures of health. Since the mid-1980s, the long-assumed superiority of urban areas with respect to health and child survival has been called into question (Brockerhoff and Bren- nan, 1998). Debt crises and structural adjustment have led to retrenchments of many government subsidies, which had disproportionately benefited urban res- idents. Yet even as these funds have been cut, high rates of urban population growth have generally continued. Population growth has often taken the form of rapid, unplanned expansion of low-income settlements on the peripheries of large cities, where health and other public services are lacking. Although the urban poor may be better equipped with some services than the rural poor, many of the urban poor also lack clean and affordable water, adequate sanitation, and electric- ity (Hardoy, Mitlin, and Satterthwaite, 2001; Jonsson and Satterthwaite, 2000b). In the absence of such services, the spatial concentration of urban poverty hastens the circulation of communicable diseases. Researchers have recently raised the possibility of a reemergence of the urban health penalties seen in the nineteenth century. They have stressed repeatedly Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World INTRODUCTION 23 the need to pay close attention to the malign influences of spatially concentrated poverty (Harpham, Lusty, and Vaughan, 1988; Tabibzadeh, Rossi-Espagnet, and Maxwell, 1989; Stephens, 1996). Where data exist, studies of urban slums and shantytowns have often revealed rates of morbidity and mortality similar to those in rural areas, and in some cases far higher. Perhaps it is not surprising, then, that neo-Malthusians have portrayed large cities as centers of poverty and social collapse (see, for example, Kennedy, 1993, or Linden, 1996). Although they have not entirely neglected the topic, demographers have de- voted insufficient attention to the study of intraurban differentials in health. Only a few studies with a demographic focus, such as that of Timaeus and Lush (1995), have explored in detail how negative spillovers, or “externalities,” influence health conditions in spatially concentrated urban populations. No longitudinal study of which we are aware has linked health or health-seeking behaviors to measures of neighborhood social interaction, networks, and social capital. Nor have interur- ban health differences received adequate attention. As the conventional wisdom has it, health conditions are better for residents of large cities than for those in smaller cities, towns, and rural villages. Can this be true if an urban penalty is emerging? Cities, Their Regions, and the International Economy Spatially disaggregated data are needed to understand the influence of local con- texts on fertility and health, and are of particular interest in zones where urban and rural activities are interpenetrating. In some geographic regions—the phe- nomenon has been examined most closely in Southeast Asia—rural economies and lifestyles appear to be undergoing a qualitative change, increasingly assuming characteristics that were formerly considered urban. More rural residents work outside agriculture; rural economies are increasingly diverse, mixing agriculture with cottage industries, industrial estates, and suburban development; and many rural residents are, of course, linked to city life through spells of migration and even through commuting. In some developing regions, one sees the emergence of megaurban areas in which it is difficult to say where a particular city begins and ends. The reconfiguration of urban space is manifested in the outward spread of urban activities, such as industry, shopping centers, suburban homes, and recre- ational facilities, which are penetrating what was once rural territory. In short, the functions and roles of cities that connect them to surrounding territory are changing in ways that threaten the relevance of administrative bound- aries (McGee, 1991). By shading and obscuring boundaries, such changes are causing researchers to question the value of urban/rural dichotomies, which ap- pear increasingly simplistic. The interpenetration of activity is also forcing a reassessment of the essential nature of rurality, attracting new attention to mea- sures of the remoteness of rural sites from the cities of their regions (Coombes and Raybould, 2001; Hugo, Champion, and Lattes, 2001). Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World 24 CITIES TRANSFORMED Much as the economy of S˜ao Paulo evolved over the course of the last century, with its evolution punctuated by crises in the international markets, we can expect modern cities to be reshaped by global economic forces over the course of the cen- tury ahead. Newly globalized circuits of finance, trade, and information exchange are linking rich countries with some poor countries, and connecting some urban residents of poor countries to their counterparts elsewhere. Many poor countries are industrializing rapidly, while advanced economies are taking steps away from manufacturing into the sectors of finance, specialized services, and information technology. These changes are forcing countries—and individual cities—to rethink their comparative advantages. To be competitive in global markets, cities are finding that they need to establish themselves as strategic nodes in international networks of exchange. Cities increasingly compete against each other, striving to present the image and provide the infrastructure demanded by international firms so as to attract greater foreign investment and generate new jobs. As they link them- selves to global markets, cities are increasingly exposing their residents to the risks, as well as the benefits, of being more tightly integrated into world networks of finance, information, and production. But cities vary greatly in their exposure to such risks and benefits, and the implications depend on national contexts and levels of development. International orientations are emerging so quickly, especially in the Asia Pacific region, that it is difficult to discern the full implications for demographic behavior. It is obvious that the benefits of globalization are being distributed in a highly uneven fashion. Very few African cities have benefited from direct for- eign investment in manufacturing, whereas foreign capital has gone to a number of cities in Asia and Latin America. To the extent that some cities succeed in at- tracting foreign capital and to the extent that this capital is spatially concentrated (Douglass, 1997), new loci of economic activity can be expected to emerge, with some areas experiencing rapid growth while others decline. Because foreign di- rect investment is usually distributed unevenly across national landscapes, patterns of migration are likely to be reshaped. Wage rates and the returns to schooling for some categories of workers may also be affected. Furthermore, as large cities enter the international competition for resources, they may lay claim to quantities of physical capital that might otherwise have gone to smaller cities. The result may be a further widening of the gap between resource-poor small cities and large cities that are already better endowed with private capital and infrastructure. But all this is speculation: although powerful forces are afoot, we cannot yet say where they will lead. Cities are a nation’s gateways to international markets, and city populations can be among the first beneficiaries of the waves of technological change that stream through these markets. City residents can also find themselves among the first victims of price spikes and exchange rate crises. Engagement with these markets may well come at the price of urban economic volatility. Still, it is not a Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World INTRODUCTION 25 given that international economic shocks will have greater impacts on urban than rural residents. As will be discussed later, the political economy of crises can be exceedingly complex, making the spatial distribution of their effects difficult to predict (Fallon and Lucas, 2002). Governance A remarkable transformation is under way in developing-country cities that may be of first-order importance to policies in the areas of health and reproductive health. We refer to the phenomenon of decentralization, a process in which na- tional governments are devolving some of their powers and revenue-raising au- thority to regional, state, and local units of government. The rate of change is astonishing, as is the diversity of countries in which these reforms are being undertaken. The pace and variety of decentralization initiatives have occasioned an out- pouring of research in political science, public finance, and urban administration. In these literatures it is recognized that a new cast of policy makers is being assem- bled, and that many on the staffs of local and regional governments will be issuing policies and monitoring implementation in areas in which they have little previ- ous experience or expertise. As municipal and regional governments take up new responsibilities for service delivery in health and education, among other things, on what basis will they make their decisions? In decentralized systems, where will the technical expertise be located in such areas as family planning? How will information be conveyed from national ministries of health to such lower-tier gov- ernments, and how will it be returned to the ministries to guide their allocation of resources? What role can be envisioned for private national medical associations? Who will attend to the question of equity in reproductive health service deliv- ery when services are arranged and monitored by different units of government? These are large and difficult questions, and of course they extend beyond health to touch on many roles and aspects of government. THE PANEL’S CHARGE The transformations just reviewed suggest the need for a thorough reappraisal of what is new in the process of urbanization in developing countries, how de- mographic perspectives can enhance understanding of the process, and what pol- icy revisions and initiatives are likely to be needed. At present, demographic researchers are ill positioned to shed light on these matters. Although vigorous programs of urban research are under way in other fields—including international health, political science, public finance, and, lately, economics—the lack of ac- tivity in demographic research circles has left these fields without the benefit of demographic insight. In economics, for instance, elegant theories have been fash- ioned to explain why large cities grow more slowly than small ones, evidently Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World 26 CITIES TRANSFORMED without taking lower fertility rates into account. And it can be argued that the low profile of urban demography has left important institutions without the resources they need to maintain the urban research infrastructure. Reference was made earlier to Preston (1979) and the United Nations (1980), which are the landmarks in urban demographic research. The world of research has changed in many ways since these reports were issued. Sample surveys are utilized far more today than was the case in the 1970s, and demographic theories have come to emphasize individual-level motives and behavior, paying decidedly less attention to the behavior of population aggregates. Relatively few demog- raphers now work with census data for developing countries, and fewer still are able to use data on the populations of the individual cities of these countries. The great demographic resources of the modern era—the Demographic and Health Surveys (DHS) and the city population data in the United Nations’ Demographic Yearbook and World Urbanization Prospects—are not themselves directly link- able because until recently the necessary geographic identifiers were expunged from the DHS public-use datasets, and the United Nations datasets have not been publicly available in computerized form. It is disconcerting to realize that as we enter the twenty-first century, the world of demographic research lacks the basic infrastructure to address the urban challenge ahead. Recognizing the need for a major fresh inquiry, the National Research Coun- cil formed the Panel on Urban Population Dynamics. The panel’s mandate was to develop greater understanding of the dynamics of urban population growth, as well as its causes and consequences, as a step toward helping governments better manage the environmental and social service problems that accompany the rapid growth of urban areas in poor countries. The panel focused on improving knowl- edge in six areas: • Urban population dynamics and city growth • Social and economic differentiation within and across cities • Fertility and reproductive health in urban areas • Mortality and morbidity in urban areas • Demographic implications of a changing global economy • The challenge of urban governance In each of these areas, the panel was charged with synthesizing results from exist- ing and emerging research, as well as identifying new directions for research that are scientifically promising and have the potential to better integrate population and public policy. Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World INTRODUCTION 27 STUDY SCOPE AND APPROACH The panel’s first concern was how to define the boundaries of its undertaking. Ur- banization, itself the product of fundamental economic and technological change, arguably affects every aspect of social life (Davis, 1955). In reviewing develop- ments from the onset of the industrial revolution to 1950, Bairoch (1988) main- tains that there was really no aspect of the demography of cities that did not exhibit specifically urban traits. In sifting through priorities, the panel endeavored to iso- late these distinctively urban features. We tried to determine the value added by an urban perspective on demographic behavior and policy. The dilemma through- out was to single out what is distinctive about urban environments without placing undue emphasis on urban/rural differences, which in some regions are beginning to fade. To address its task, the panel reviewed the existing literature and conducted a substantial amount of new data analysis. We relied heavily on a database created by linking individual DHS surveys with information on city population sizes taken from the United Nations’ Demographic Yearbook, a publication that includes data for cities as small as 100,000 in population and all national capitals. (Chapter 4 reviews the many difficulties encountered in linking the survey and city data.) The linked DHS–United Nations database contains comparable measures for a broad range of demographic outcomes from as many as 90 surveys in more than 50 countries. For the reasons mentioned above, the DHS surveys have not been systemati- cally analyzed from an urban perspective. The advantages of these surveys lie in their breadth, their consistency, and the comparability of questions and methods across surveys, as well as in good (if incomplete) regional coverage. These sur- veys also suffer from significant disadvantages—their samples are generally too small to permit reliable description at the level of individual cities, to say nothing of analysis of socioeconomic variation within individual cities. Only through the application of multivariate methods can one get a glimpse of this sort of variation. In addressing its charge, the panel sought to confine its efforts to areas of the most pressing need. For example, we did not exhaustively review environmental problems in cities because recent and highly capable summaries of these issues are available elsewhere (see Hardoy, Mitlin, and Satterthwaite, 2001). Likewise, issues of housing are thoroughly examined by the United Nations Centre for Hu- man Settlements (UNCHS) (1996, 2001) and Malpezzi (1999). To make best use of its limited resources, the panel focused on the critical need for more detailed demographic analysis of inter- and intraurban differentials in low- and middle- income countries. Although we could not conduct analyses at the level of neigh- borhoods, we developed a measure of relative urban poverty to explore the equity dimension of intracity variation. To determine the extent of intercity differentials, we analyzed the DHS–United Nations data by one measure of urban hierarchy— Copyright National Academy of Sciences. All rights reserved. 

Cities Transformed: Demographic Change and Its Implications in the Developing World 28 CITIES TRANSFORMED city population size—recognizing the urgent need for measures of governance and other city-specific characteristics. ORGANIZATION OF THE REPORT The remainder of this volume reports the results of the panel’s work. We first de- velop a theoretical rationale for studying urban contexts, giving an overview of re- cent thought on the importance of local social and spatial environments (Chapter 2). The report proceeds to sketch the regional context in which change occurs and reviews the basic demography of urbanization and city growth (Chapters 3 and 4, respectively). Chapter 5 examines the social and economic diversity in urban conditions of life. Despite the material advantages offered by urban life, it is evident that many city residents are unable to avail themselves of these advantages—they lack adequate food, water, and shelter. Chapter 5 docu- ments several dimensions of urban poverty and presents new findings on the extent of poverty and inequality by city size and by region. Chapters 6 and 7 then con- sider fertility and health, respectively, raising the question of whether there exist distinctively urban demographic regimes with distinctive implications for service delivery. The demographic changes examined in these chapters are rooted in the urban economy, which generates resources and establishes some of the constraints and costs that affect demographic behavior, and in urban governance, which influences how those resources are distributed and conflicting demands resolved. A defin- ing characteristic of cities and towns at the beginning of the twenty-first century is their internal diversity; the management and mediation of difference is a cen- tral challenge in urban governance. Chapter 8 addresses the urban economy and its labor markets from a demographic perspective, and Chapter 9 examines the challenge of urban governance. Finally, Chapter 10 takes stock of what has been learned and offers some thoughts about the path forward. Copyright National Academy of Sciences. All rights reserved.