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Causes of demographic change


Rapid rates of urban growth were caused initially by migration. In places, movement to the major cities has been long established, dating from as early as the end of the nineteenth century in the cases of Argentina and Uruguay. Even in the rest of the region, cityward migration is hardly a recent phenomenon, having become commonplace in the 1940s as rural people began to respond to new opportunities in the metropolitan areas (Alberta, 1977; CEPAL/CELADE, 1993; Herrera and Pecht, 1976). Between 1950 and 1960, newly arrived migrants added the equivalent of around 4 per cent of the metropolitan population every year to the populations of Bogotá, Caracas, and São Paulo. Elsewhere, the figures were less startling but still significant; 2.6 per cent to Rio de Janeiro and 2.0 per cent in Buenos Aires and Mexico City. During the 1960s, the relative weight of migration slowed but the absolute numbers of migrants moving to the major cities reached their peak (Herrera and Pecht, 1976).

The pace of migration continued to slow during the 1970s and fell markedly during the 1980s. Migration explained around half of Santiago's growth during the 1960s but only 15 per cent between 1982 and 1992. Indeed, during the 1980s, there were strong signs that as many people moved out of some metropolitan areas as moved in. Rodríguez (1993) estimates that net in-migration to Santiago fell from 10 per thousand people between 1977 and 1982 to two per thousand between 1987 and 1992. In Mexico City, CONAPO (1992) estimates that there was a net exodus of 300,000 people between 1985 and 1990.

Migration to metropolitan areas has always been affected by the nature of each nation's development path. In the southern cone, international migration was already stimulating metropolitan expansion during the last half of the nineteenth century. Elsewhere, it was only when import-substituting industrialization got under way, during the 1940s, that floods of migrants began to move towards the growing cities. It was hardly surprising that most industrial companies established factories in the major cities with their concentrations of high-income earners, their superior infrastructure, and their access to top decision-makers. Migrants followed the jobs to the cities.

Import-substituting industrialization also changed life in the countryside. By channelling investment into the cities it starved the countryside of resources. By distorting exchange rates, it discouraged agricultural production for export. By introducing modern methods of cultivation and agricultural finance into certain areas of the countryside, it led to the rapid disintegration of traditional forms of rural life. In a context of rapidly declining mortality, the expanding rural population was forced to look for work elsewhere (Castells, 1973; PREALC, 1990; de Oliveira and Roberts, 1989). Given the increasing economic opportunities available in the larger cities, many rural people moved to the metropolitan areas.

During the 1980s, of course, the pattern of development in Latin America changed. The region suffered its worst recession since the 1930s and, generally, it was the largest cities that bore the brunt of structural adjustment. Metropolitan living conditions deteriorated, real wages fell, and rates of unemployment rose. This deterioration in the quality of metropolitan life quickly became obvious to potential migrants, who began to stay at home.

With the introduction of a new model of development based on export production, freer trade and market liberalization, the balance between urban and rural living conditions changed. Some rural areas benefited from the new model as investors sought to exploit opportunities in agriculture, mining, or tourism, while most cities lost out (Daher, 1992; Gilbert, 1993; Soler and Rubio, 1992; de Mattos, 1992a; 1992b). Metropolitan populations felt the full force of liberalization and the rolling back of the state; they suffered from more pollution and traffic congestion, declines in subsidies and social welfare facilities, and a worsening in the distribution of income.

For the first time in several decades, metropolitan centres no longer attracted most investment; the economies of many smaller cities began to grow much more quickly. In Chile, cities such as Antofagasta, Coquimbo-La Serena, and Temuco experienced the fastest rates of growth. In Mexico, border cities such as Tijuana, Ciudad Juárez, and Mexicali, tourist centres such as Acapulco and Ensenada, and cities in agricultural export zones, such as Sinaloa, all grew faster than the major urban centres. In Brazil, Belém, Belo Horizonte, Curitiba, Fortaleza, Pôrto Alegre, and Salvador expanded more quickly during the 1980s than Rio and São Paulo, with the fastest growth of all occurring in cities with between 100,000 and 500,000 inhabitants (IBGE, 1992).

Despite this shift in comparative advantage, there is little doubt that metropolitan centres have retained many of their privileges. Their economic structures have been damaged but are still very strong; their social infrastructure has been weakened but is still superior to that in most other cities. As a result, most have continued to attract migrants, even during the dark days of the 1980s (CEPAL, 1991a; 1991b; UNCRD, 1994).

Natural increase

Gradually, natural increase became the most important component of metropolitan growth; by the 1960s it had become much more significant than migration. Natural increase overtook migration because the majority of the migrants were so young. Within a few years of arrival in the city, most had produced children. The contribution of natural increase to urban growth was further magnified by the fact that death rates were far lower in urban areas than in the countryside, a tendency that became even more marked as mortality in the giant cities continued to fall.

Lower death rates in the metropolitan areas were a consequence of their superior living and health conditions. For example, Caracas has one doctor for every 600 people compared to the Venezuelan average of one per thousand. In Colombia, 90 per cent of births in Bogotá are attended by a doctor compared to only 70 per cent nationwide. In Peru, 77 per cent of the mothers who gave birth between 1986 and 1991 had received prenatal medical care compared to a national average of only 43 per cent. Of course, major variations in death rates are apparent between metropolitan areas; in Santiago infant mortality rates average only 14 per thousand live births, whereas in Rio de Janeiro they average 46 (table 2.5). Nevertheless, infant mortality rates in most parts of the countryside are much higher than in Rio.

If longer life expectancy and falling rates of infant mortality have raised the pace of natural increase, trends in fertility have had the opposite effect. For many years, rates of metropolitan fertility have been in decline. Fertility rates have fallen for several well-documented reasons (UN, 1987). A key factor has been the increasing availability of modern contraception in the large cities. Rates of use are very much higher than in non-metropolitan areas and the use of contraceptives in most metropolitan cities doubled between the 1950s and 1960s and the 1980s. By the 1980s, couples in Bogotá, Mexico City, and Rio de Janeiro were using contraception as frequently as couples in Buenos Aires had done in the early 1960s. At that time, fertility in Buenos Aires had fallen to levels which could barely maintain the population.

Table 2.5 Death rates, life expectancy, and infant mortality in Latin America, 1950-1970,1970-1979, and 1980-1990

Country and city

Death rate (per thousand)

Life expectancy at birth (years)

Infant mortality (per thousand live births)

1950 1969 1970-1979 1980-1990 1950-1969 1970-1979 1980-1990 1950 1969 1970-1979 1980 1990
Argentina 13 (60) 9 (75) 7 (85) 66 (60) 68 (75) 70 (85) 58 (60) 45(75) 27 (89)
Buenos Aires 11 (60)a - - 68 (60) - - 30 (60)a - 20 (89)
Brazil 11 (55) 8 (79) 8 (85) 51 (52) 62 (79) 64 (85) 140 (50) 75(79) 63 (87)
São Paulo 9 (55) 7 (79) - 48 (40) 64 (79) 68 (85) 115 (50) 55(79) 35 (88)
Rio de Janeiro - - - - - - - 58(78) 46 (84)
Chile 12 (60) 8 (75) 6 (90) 57 (60) 65 (75) 71 (85) 115 (60) 80 (70) 17 (89)
Santiago 10 (60) 6 (75) 5 (90) - - - - 49 (70) 14 (89)
Colombia 12 (55) 8 (75) 6 (87) 57 (60) 63 (75) 68 (85) 97 (60) 50 (79) 40 (87)
Bogotá 6 (55) - 5 (87) - 67 (75) 69 (85) - 43 (79) 22 (87)
Mexico 13 (55) 8 (75) 6 (85) 51 (52) 61 (70) 66 (80) 114 (52) 74 (70) 41 (87)
Mexico City 11 (55) 7 (75) _ 51 (40) 63 (70) 69 (80) 132 (50) 75 (70) 30 (87)
Peru 25 (50) 18 (62) 9 (87) 49 (62) 56 (72) 61 (87) 136 (62) 105 (75) 64 (86)
Lima 13 (50) - - - - - - 61 (74) 30 (86)
Venezuela 13 (55) 6 (75) 5 (87) 60 (62) 67 (75) 70 (87) 80.5 (60) 45 (75) 36 (87)
Caracas 7 (55) - - - - - - - -

Sources: Cámara de Comercio de Bogotá, n.d.; CELADE, 1993b; Rodriguez, 1993; CEPAL/CELADE, 1993; United Nations, 1993c, Recchini de Lattes, 1971; Demographic Health Survey and World Fertility Survey series, various years.
a. Federal Capital.

Of course, the availability of contraception does not mean that families will use it. However, there appears to be common agreement that urban, and particularly metropolitan, life reduces the desire to have children. A key factor is that the urban productive system reduces the economic value of children and increases the cost of bringing them up. Urban life also increases the chances of social mobility, providing that the birth of children is postponed. City life encourages rationality in family decision-making and raises the status of women by opening up new kinds of career beyond motherhood.2

Clearly, couples in most large Latin American cities now share similar attitudes towards the size of their family. For that reason, fertility rates across metropolitan areas have become more and more equal. Fertility rates in many erstwhile highly productive cities have fallen particularly rapidly. In Mexico City and Buenos Aires, gross fertility rates, which had been very different in 1962 at 5.8 and 2.1 respectively, had become quite similar - 3.0 and 2.7 - by the 1980s. Even if it is clear from Rosen and Simmons' (1967) classic study that fertility levels are determined less by the fact of metropolitan life than by the characteristics of particular cities, fertility levels in most urban areas are now remarkably similar (table 2.6).

Indeed, the decline in fertility rates has spread far beyond the major cities. Until the 1980s, fertility rates were much lower in the largest cities than in other areas. Over the last decade, however, national, urban, and metropolitan fertility rates have become much more equal (table 2.6). In several countries, some secondary cities now have lower fertility rates than the metropolitan centres. In Colombia, for example, Medellín and Cali have lower fertility rates than Bogotá (Camera de Comercio, n.d.).

Age and sex structure

During the last thirty years, Latin America's giant cities have experienced a significant increase in the population of working age (20-60 years). This expansion has been a direct result of the tendency for young adults and their children to move to the city. At first, their arrival lowered the average age of the metropolitan population, but, as both migration and fertility rates began to fall, the average age began to increase. In Mexico City, for example, 33 per cent of the population was under 15 in 1990 compared to 42 per cent twenty years earlier (CONAPO, 1992). In Bogotá, 33 per cent of the population was under 15 in 1985 compared to 45 per cent twelve years earlier (Camera de Comercio, n.d.). As a result, the share of the population in the working age group has increased markedly.

Table 2.6 Fertility rates, number of children desired, and use of contraceptives in Latin America, 1950-1970,1970-1979, and 1980-1990


Gross fertility ratea

Average number of children desired

Use of contraceptivesb

Country and city 1950-1970 1970-1979 1980 1990 1950-1970 1970-1979 1980-1990 1950-1970 1970-1979 1980-1990
Argentina 3.1 (62) 3.1 (72) 3.1 (80) - - - - - -
Buenos Aires 2.1 (62) 27 (72) 2.7 (80) 2.7 (62) - - 62 (62) - -
Brazil 6.2 (62) 4.5 (70) 3.5 (85) - - 2.8 (86) - - 57 (86)
São Paulo 5.0 (62) 3.6 (70) 2.9 (85) - - 27 (86) - - 63 (86)
Rio de Janeiro 3.6 (62) - 2.6 (85) 2.8 (62)   2.3 (86) 32 (62)   63 (86)
Chile 5.3 (62) 3.3 (72) 2.6 (90) - - - - - -
Santiago 4.2 (60) 2.7 (72) 2.3 (90) - - - - - -
Colombia 6.8 (62) 4.4 (75) 2.9 (90) - 4.1 (76) 2.6 (90) - 30 (75) 55 (90)
Bogotá 5.7 (62) 2.8 (75) 2.4 (90) 3.4 (62) 3 5 (76) 2.4 (90) 27 (62) 57 (75) 62 (90)
Mexico 6.8 (62) 6.2 (75) 3.6 (86) - 45 (76) 3.0 (87) - 23 (75) 44 (86)
Mexico City 5.8 (62) 4.8 (75) 3.0 (86) 3.4 (62) 3.9 (76) 2.5 (87) 25 (62) 46 (75) 56 (86)
Peru - 5.3 (76) 4.1 (86) - 3.8 (77) 2 7 (87) - 11 (76) 46 (86)
Lima - 3.4 (76) 2.5 (86) - 3.5 (77) 2.5 (87) - 49 (76) 63 (86)
Venezuela 6.5 (62) 4.9 (76) - - 4.2 (77) - - 49 (76) -
Caracas 5.2 (62) 3.3 (76) - 3.4 (62) 3.5 (77) - 42 (62) 60 (76) -

Sources: CELADE, 1993b; Rodriguez, 1993; United Nations, 1993c and 1987; CELADE-CFSC, 1972. Demographic Health Survey and World Fertility Survey series, various years.

a. Refers to the number of women aged between 15 and 49 years in a state of union at the time of the survey.
b. Includes modern and traditional methods.

Gradually, the proportion of older people has also begun to increase. In Santiago, the population aged 65 years or over increased from 4.1 per cent of the total in 1960 to 6.4 per cent in 1990 (Rodríguez, 1993). Currently, however, an ageing population is a significant issue only in the major cities of Argentina and Uruguay, where it is an outcome of the early experience of urban growth and the long-established slowing in the fertility rate. In Buenos Aires, 13 per cent of the population in 1980 was older than 60 (Recchini de Lattes, 1991).

Most metropolitan areas contain more women than men, a direct outcome of the higher incidence of women in migration flows (CEPAL/CELADE, 1993). Young women have long been attracted to the largest cities by the availability of work in commerce and domestic service (Alberta, 1977; Elton, 1979; Recchini de Lattes, 1991; Singelmann, 1993; Szasz, 1992). This tendency does not seem to have been affected by the recent slowing of migration.

The spatial pattern of metropolitan growth

Most urban planners in Latin America have long been concerned at the way metropolitan areas have spread outwards in apparently uncontrolled and explosive ways. The suburbs have spread like ink across blotting paper. In the process they have left enormous swathes of unused land within the urban perimeter and created vast low-income settlements with poor links to the rest of the metropolis (see chapter 4). This tendency has accentuated the problems of these cities, increasing transport problems, weakening infrastructure systems further, and putting impossible demands on local authorities with limited financial resources (Bähr and Mertins, 1993; CED, 1990; PREALC, 1990; Tulchin, 1993). Uncontrolled urban expansion has also led to the occupation of land quite unsuited to dense urban settlement. Major problems now face the settlers of low-income settlements located on land liable to flood, particularly in parts of Buenos Aires, Santiago, and São Paulo, and on steep hillsides subject to slippage, particularly in cities such as Caracas and Rio de Janeiro (Fadda, 1992; Ibarra et al. (eds.), 1986a; UNCRD, 1994).

Rapid metropolitan growth has caused additional problems when it has occupied fertile agricultural land. This has been a major headache in Bogotá, where the city is located at the edge of a large plain producing much of Colombia's wheat, potato, and barley and the bulk of its flower exports (Rode, 1992). In Lima, where the urban area increased thirty times between 1940 and 1993, the Province of Lima has lost three-quarters of its agricultural land (de Llona, 1991; Muñoz, 1991).

As the cities have expanded outwards, population growth in the central areas has slowed down. Few of the old administrative centres of the megacities have grown much in recent years, and in the case of the Federal District of Mexico, its population actually declined by 600,000 people between 1980 and 1990. This tendency has been particularly marked in the oldest parts of the cities since around 1970 (see chapter 4). The populations of central Buenos Aires, Caracas, Lima, and Mexico City are now in decline, and in Santiago there is public concern about the "depopulation of the historic core of the city" (CED, 1990; Rodríguez, 1993). Only the two Brazilian mega-cities seem to have escaped this trend: a result of new skyscraper developments and the development of increasing numbers of low-income tenements.

Since the 1970s, and in accentuated form during the 1980s, metropolitan expansion has taken a very different form from that in the past. Much of the growth is no longer within the urban perimeter. It has shifted to a number of towns and secondary cities within the wider metropolitan region but some distance from the main urban centre. This process has been one sign of the "polarization reversal" discussed earlier and is a first step in the creation of conurbations like those of Europe, the United States, and Japan.

As transport and communication networks have improved, and as infrastructural provision has been extended to secondary centres, companies have been able to operate successfully beyond the confines of the region's principal city. The process is not new in Latin America but it has recently intensified (Garza, 1978; Sabatini, 1991). The economic hinterland of Mexico City, which has gradually embraced Cuernavaca, Pachuca, and Toluca, now extends as far as Puebla and Querétaro, 128 and 224 km respectively by motorway from the capital (CONAPO, 1992) (see chapter 8). In Brazil, São Paulo's hinterland now embraces Campinas, Cubatão, Santos and São Jose dos Campos. A discontinuous economic and urban complex now spreads hundreds of kilometres from the centre of São Paulo (Cano and Pacheco, 1991; de Mattos, 1992a; Kowarick and Jacobi, 1986; UN, 1993c; see also chapters 4 and 10). In Venezuela, a similar kind of process has been emerging for a number of years, with a chain of cities, including La Victoria, Maracay, and Valencia, spreading westwards from Caracas along the motorway to Puerto Cabello.

The tendency towards "concentrated deconcentration" has sometimes been encouraged by the state. In Argentina, the state has encouraged industrial companies to move to the outskirts of Greater Buenos Aires (Pesci and Ibañez, 1992). In Chile, there are plans to stimulate development in a wide area around Santiago, which include some population relocation and major improvements to the transportation system. The area concerned stretches 160 km to the west, 96 km to the north and 240 km to the south (Echeñique, 1992; Necochea, 1991; Sabatini, 1991).

Manufacturing industry has been the prime mover in this trend towards urban deconcentration and other sectors have lagged behind; indeed, tertiary activity has sometimes moved in the opposite direction, becoming more concentrated in the principal city. As manufacturing has moved out, however, the figures suggest that mega-cities have lost some of their national importance in this sector. Such figures are misleading in that, while the principal city often has a lower share of manufacturing employment and value added, its wider region has often strengthened its hold.

Only rarely has this trend been fully reflected in terms of the distribution of people. In Brazil, the area around São Paulo has grown more slowly than urban areas generally, the combined population share falling from 21 per cent of the state's population to 19 per cent between 1980 and 1991. Similarly, in Chile, the Santiago macro-region has grown more slowly than the nation's urban population. In the case of Mexico, the main metropolitan region has lost out even more dramatically, the combined urban population of the area between Mexico City, Puebla-Tlaxcala, Toluca, and Cuernavaca falling from 36 per cent in 1970 to 32 per cent in 1990 (Ruiz, 1993).

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