Describing population and urban change in Africa over the last 10-15 years is particularly problematic because of large gaps in basic demographic data. Africa has certainly had among the most rapid population growth and urban change of any of the world's regions in recent decades yet for almost half of its nations, there is no census data available since the early 1980s. For many nations, all figures for national, regional and city populations are estimates or projections based on census data from the 1970s or early 1980s so it is impossible to describe changes in national and urban populations. There are also many countries where war or civil strife make any estimates for city or regional populations questionable - for instance in Somalia, Rwanda, Burundi and Liberia.

In the absence of census data, one becomes more reliant on studies of particular settlements or city neighbourhoods or sectors that give an insight into the scale and nature of change although it is never possible to know how representative this change is of other settlements or city neighbourhoods.

Most of the nations with the fastest growing populations are now in Africa, although this is a relatively recent phenomenon. It was only in the first half of the 1970s that the region's population came to grow more rapidly than that of Latin America and the Caribbean. Table 2.21 shows how many countries had populations that grew more than threefold between 1950 and 1990 - although some caution is needed in reading the statistics in this Table as many of the population figures for 1990 are based on estimates or projections.

Looking back over the period from the early 1960s, when most African countries obtained formal independence, to the mid 1990s, African cities have changed in at least four major ways: their size, their spatial organization or morphology, the quality and distribution of public services and infrastructure, and their employment base.

Size is the most obvious difference, since the population of most African cities have grown severalfold over the last few decades; some have grown more than tenfold during this period. Exact comparisons over the same time period are difficult to obtain because of differing intercensal periods; and for many countries whose recent censuses were in the late 1980s or early 1990s, the final results are still not available. Nevertheless, two clear trends are visible. First, the largest cities have continued to grow in population, although by the 1980s and 1990s their rates of growth have declined in comparison to the spectacular rates of growth during the 1960s and 1970s. And whereas the main component of the growth of the largest cities was rural-urban migration in the earlier post-independence period, natural increase is now the major element. Second, in many countries, many or most medium-sized cities have been growing more quickly than the largest cities. This may very well be partly a result of the more difficult economic situation facing urban dwellers as a whole during the last decade and a half; but it may also be reinforced by the steadily deteriorating condition of infrastructure and public services in the largest cities. These factors, in turn, reflect the determination of many African countries to favour smaller cities in investment and planning decisions, however much the implementation of these policies of spatial decentralization fall short of their original goals.

The deterioration of services and infrastructure is another common trend of the 1990s. This is to some extent an inevitable result of the fact that, as national (and urban) economies stagnate in absolute terms, at the same time as urban populations across the continent continue to grow (the United Nations estimates this for the whole region, the growth rate is approximately 4.5% per year) the resources necessary for roads, sewers, water systems, schools and hospitals simply cannot keep up with the needs of the population. While there is a clear differentiation between the living conditions of the (relatively) small groups of upper-level managers, foreign diplomats, senior politicians and successful businessmen on the one hand, and the growing numbers of lower-income urban dwellers on the other hand, there is also a general deterioration in the public services and infrastructure available to everybody.

Changes in the labour market have been very dramatic since the 1960s. In the decade following independence, the educational system was expanding at every level, and African graduates had little difficulty finding good jobs in either the public service (and its parastatal arms) or the large-scale private sector. Now, the public service is contracting everywhere, parastatals are being disbanded or privatized to cut back on the numbers of employees they support, and even university-educated professionals have great difficulty in finding secure employment, if in fact they obtain suitable employment at all. Partly as a counterpart to the decline in well-paid, secure employment, more and more urban residents have found work in the burgeoning "informal", or small-scale, unregulated sector where a bewildering variety of activities have developed to respond to the needs and financial capacity of the poor. These developments are reflected in the continued growth of spontaneous, popular housing areas; in the ever increasing numbers of ambulant hawkers and foodsellers on every corner of many downtown African cities; in the increase in size and numbers of open-air markets; in the pervasiveness of small-scale, privately owned public transport vehicles that have taken over the market from the monopoly state-regulated bus companies; and in a virtual explosion of small trades and services dealing with almost every facet of life in the city. From an overly regulated city which reflected the needs of the erstwhile colonial powers to control African urban life in every possible way, we are witnessing the birth of a new city form which reflects the new African reality. What could be called the "self-help city" in the 1970s, might very well be called the "informal city" in the 1990s.

All these changes have had a major effect on city form. Where once the central business district, with its clean, wide streets and high-quality shops and offices was the focus of urban life -- in both the large capital cities and in secondary cities as well -- the centre of gravity has shifted. Not only are central business districts more poorly maintained and more populated with small-scale hawkers and vendors than in the past, but more and more of the population is moving to the periphery of the larger cities, where land is cheaper and much more easily accessible, where shelter can be constructed economically using locally-available materials, and where harassment from the police and restrictions of the formal planning system are rarely felt. This horizontal expansion of the African city into its rural hinterland not only attenuates major infrastructural elements such as piped water, electricity, sewerage and roads to a point where their efficacy is greatly reduced; but it also adds considerably to the costs of such services as education, health and social assistance. As these peripheral settlements expand, and the public resources to service them continue to contract, a new approach to the planning and management of African cities will have to emerge if they are going to survive as viable social and productive entities in the 21st century.

However, there were certain cities that fared better - especially in North Africa. For instance, the city of Tunis in Tunisia presents a different picture, especially in the city centre and the area around the international airport which has been transformed by national and international business corporations and international tourism. Although Tunis also has serious housing and other urban problems, these are not of the same scale and nature of most cities in sub-Saharan Africa.

An understanding of urban change in the last ten to fifteen years requires some consideration of the colonial experience, since it is only three decades or so since most countries in the region achieved political independence. Although urban centres and urban civilizations had grown and flourished in many parts of Africa prior to colonial rule, it was largely under colonial rule that the major cities and the urban systems that exist today were defined. In addition, it was the institutional structure left by colonial rule and initially little modified by newly independent governments that has proved so ineffective in managing urban change.

This was the case for three main reasons. In the first place, a great number of cities which became important during the colonial and post-colonial periods simply had not existed before colonial rule. Nairobi (now the capital of Kenya) was established on an open plain in 1899, in order to facilitate the building of the railway which was to run from Mombasa on the East African coast to Kampala in Uganda. Harare, the capital of Zimbabwe was originally built and administered by the British South Africa Company, beginning in 1890 when the Union Jack was first raised on the previously uninhabited site of (what was then) Fort Salisbury. Abidjan, now the largest city in Côte d'Ivoire, was at best a small lagoon village before being chosen by a certain French Captain in 1891 as the terminus for a railway line which would link the Atlantic Coast with the vast Niger hinterland being developed by French military and commercial interests. Finally, Johannesburg was established in the year 1886 on the site of a digger's village being developed on unclaimed farmland, in the immediate vicinity of a major gold mining complex. All these new towns -- and many others, such as Cotonou, Libreville, and Bangui (as capital cities); and large provincial towns such as Bouaké, Tamale, Enugu, Lubumbashi and Mwanza -- developed as major centres of commerce and of administrative activity. Because their major purpose was to strengthen the ties between the metropolitan country and the colonial territory, they were often located on or near the coast or a major waterway. A new colonial urban system began to emerge, displacing internal networks of trade and influence which had developed over many centuries.

A second major urban effect of colonialism in Africa was the establishment of powerful currents of rural-urban migration. Although African populations had been moving around the continent for centuries in response to commercial opportunities, variations in environmental conditions, political upheavals, and the depredations resulting from the slave trade, colonial regimes and the economic activities which they promoted raised the level of migratory activity to a much higher level. As a cash economy was introduced, and goods and services could be obtained in exchange for wages, there were incentives for African labourers to migrate to work on mines, plantations, and urban employment. Most migration was rural-rural, but perhaps one-quarter of all migrants went to the towns.

By the mid-1950s, the "winds of change" which nationalist movements brought to the African continent, combined with an increasing concern with African labour efficiency, led to a reassessment of the African role in towns -- at least in the regions of eastern, central and southern Africa, where government control over African urban integration was the most marked. One of the main reasons for increasing administrative and political concern, near the end of the colonial period, was the very rapid increase in the population of many cities, largely the result of rapid in-migration. Annual average population growth rates of 5 to 7 percent a year were common among the major cities in the 1950s and 1960s while some maintained even more rapid population growth rates for short periods.

In general, these growth rates varied according to local political and economic circumstances. For example, most African cities grew quickly during the 1920s, slowed down during the 1930s, began to grow again during and after the Second World War, and slowed again during what were often political uncertainties during the 1950s. With Independence, they began to grow rapidly, a pattern which continued through to the 1980s.

The third major effect of colonial urbanization was the physical structure of cities that was bequeathed to the African governments that took over power from the late 1950s (for Ghana, Egypt, Tunisia and Morocco), through the 1960s (for almost all the rest of the Anglophone and Francophone countries) through to the 1980s. Looking at the totality of Francophone cities in thirteen West African countries at the end of the 1980s, a major study argues that

After Independence, many African countries sought to respond to this colonial urban contradiction by major exercises in "master planning", and by large-scale government-sponsored construction of residential dwellings. Neither proved adequate to the problems of urban management. For urban planning, typically, a major expatriate planning firm would produce a master plan for the future development of the capital city. The plan would contain an analysis of urban form and function, some analysis of likely future growth patterns, and a number of technical maps and plans such as a detailed land use zoning map, plans for infrastructural development, and some proposals about procedures, regulations and even institutional reforms necessary to carry out the plan. These plans were the direct descendants of numerous plans produced during the colonial period, although successive documents tended to include more and more data of a sociological and economic nature. The city of Abidjan in Côte d'Ivoire had six major planning documents from 1928 to 1990; Dar es Salaam had three plans from 1949 to 1977; Nairobi had three from 1948 to the mid 1980s. While these plans often had an important influence on the overall approach to land-use planning in the central areas of the larger African cities, they failed to capture the speed and direction of growth in the peripheral areas, and in any case were almost never supported by the level of capital expenditure necessary to implement their infrastructural projections.

In the absence of major capital projects developed within the master plan framework, most urban planning decisions took place within the parameters of building and development regulations that were little more than copies of the existing legislation and bylaws in Britain, France and Portugal. These usually ascribed a large and complex role in land use management and other aspects of urban management to the public sector. Such European influence on African urban planning was reinforced by the fact that not only were virtually all urban planners working in Africa Europeans of origin until at least the mid-1960s, but there were no schools of architecture or urban planning located on African soil (outside of South Africa) until the first decade after independence. Until at least the mid-1960s, virtually all the directors of urban planning in African countries were of European origin. Urban planning legislation was supplemented by building codes which, in many cases, were also very closely modelled on European regulations.

Within the terms of reference of the urban planners, but with a dynamic and importance of their own, were policies for the development of residential housing. Two of the hallmarks of the colonial approach to African urban housing in the 1950s were the redevelopment of decaying 'core' areas combined with the removal of 'slums' or squatter areas; and the construction of large rental (sometimes tenant-purchase) public housing estates. Once Independence was accomplished, these policies were pursued by the successor governments. For instance, large scale "slum clearance" programmes were implemented in many cities - including Dar es Salaam, Nairobi, Dakar, Lomé, and Abidjan. And while in some instances, public housing was built for at least a proportion of those whose houses were destroyed, most of the displaced could not find alternative housing nearby to the areas where they had previously lived.

The public housing programmes were also rooted in colonial precedents. During the colonial period, large estate housing projects were undertaken in such countries as Southern Rhodesia (now Zimbabwe), Kenya, Senegal and the Ivory Coast, where the government (and parastatal agencies such as the railways and port authorities) needed to house their employees. After independence, this state-centred approach to housing developed more widely, with many countries establishing national housing agencies with an important mandate to improve housing for Africans. Behind this drive was the feeling of many urban Africans that their housing conditions should be upgraded in line with their changed political status.

However, very few of the public housing agencies produced enough housing units to make much impression on improving housing and living conditions and many of the units they produced went to middle or upper income groups. There were some exceptions - for instance the large construction programme in the Côte d'Ivoire of SICOGI (Société Ivoirienne de Construction et de Gestion Immobilière) and SOGEFIHA (Société de Gestion Financière de l'Habitat) and the very large land development programme within Abidjan undertaken by SETU (Société d'Equipement du Terrain Urbain). But the role of public agencies in supplying urban housing in Côte d'Ivoire was also drastically curtailed in the 1980s.

As public housing programmes remained relatively small and usually used up most of the government resources devoted to housing and as official norms, codes and standards made the cheapest "legal" housing too expensive for most city households, so an increasing proportion of city inhabitants came to live in illegal or informal settlements. While there are many definitions of this type of housing, and many local variations around the main tendency, the central defining elements are usually twofold: (1) the housing in question is either illegally built (i.e. without formal permission from the authorities) or (and in many cases in addition) it sits on land which has not been properly purchased through the formal system and zoned for residential development; and (2) few, if any services -- such as water, roads, sewerage and stormwater drainage, electricity, telephones, and community facilities (such as clinics and schools) -- are built in the immediate neighbourhood. In general, there is a relationship between the formal illegality of a settlement and the quality of the housing stock within it, since owners (who are often landlords) will not invest in high quality building materials or in improvements if they cannot borrow against the property, or if there is a chance their dwelling will be demolished by the authorities. Thus, the more precarious a location from a legal point of view, normally the lower the quality of the dwellings within it. This general rule is modified in the case of neighbourhoods which, for political or other reasons, are relatively secure even if they are not legally sanctioned in a formal sense.

During the 1980s, the increase in the level of spontaneous, or informal housing in and around African cities reflected the almost total inability of most national or city authorities to provide adequate serviced land and infrastructure to their growing populations. The 1980s and early 1990s thus became, in common parlance, a period of "urban crisis" across the continent. The crisis -- which itself was a reflection of declining or stagnating economies in the face of continuous rural-urban migration, had three major components: a decline in levels of formal employment, and a corresponding rapid increase in "informal sector" activities in many key areas of the urban economy; a deterioration in both the quality and distribution of basic services; and a decline in the quality of the urban environment, both built and natural. All these changes adversely affected the quality of urban life for everyone, but particularly for low income groups.

EMPLOYMENT: In the years immediately following independence in most African countries, Africanization of the public service and an expansion of parastatal agencies led to a high rate of new employment creation in urban areas, particularly in the capital cities and large regional centres. By the 1970s, these increases were paralleled by increases in both the quantity of manufacturing jobs available (most of them in the largest towns), and in average manufacturing wages. At the same time, agricultural wage employment fell, or stagnated in many countries, thus increasing the attractiveness of the larger towns to rural migrants who could not gain sufficient incomes by working in subsistence agriculture. As research has pointed out, those most likely to migrate from rural to urban areas were the more educated than their non-migrating peers; more of them also tend to be male, young, and single. Their numbers were increased after independence by a rapid expansion in primary and secondary schools in both rural and urban areas. But by the late 1960s and early 1970s, it became clear that the rate of rural-urban migration was greatly exceeding the rate of formal employment creation in Africa's cities. Total numbers of jobs created in the formal sectors (including government, the parastatal sector, manufacturing and the large-scale service sectors such as banking and tourism) were not keeping pace with the increase in the urban population, whether this was caused by rural-urban migration or by natural increase.

Figures on manufacturing employment in medium- and large-size establishments show the changes over time in one of the most important parts of the urban formal sector. In most countries, there was rapid growth in formal manufacturing employment between 1970 and 1975, followed by slower growth during 1975-80. With sharply increased oil prices after 1973, increasing foreign exchange needed to be allocated to oil (except in the few African countries which were net exporters of petroleum products), and lesser amounts were available for capital goods and the other intermediate inputs necessary for maintaining (let alone expanding) the manufacturing base. While the period from 1980-85 (which included the second oil shock) saw renewed or accelerated manufacturing employment growth in some countries, others -- particularly those with large manufacturing sectors such as Côte d'Ivoire, Ghana and Nigeria -- reported negative employment growth rates, while such countries as Kenya, Senegal and Zambia had annual increases during this period of only 4, 3 and 1 percent, respectively.

African countries cannot afford to maintain publicly-funded social security systems such as social assistance or unemployment insurance programmes that operate in most countries of Europe and North America. Thus, individuals in the labour force who cannot obtain well-paid, formal sector urban employment have a number of options. If they are migrants, they can return to rural areas to engage in subsistence agriculture (for refugees, or those who do not have access to land, this is not possible). Or they can attempt to obtain support from family members or friends living in the town; or they can engage themselves in small-scale, "informal" income earning activities in the town. For most Africans seeking urban employment, remaining in "open unemployment" is not a realistic option as few can afford to wait. As formal urban employment opportunities declined, the alternative of engaging in small-scale, less remunerative activities -- now known collectively as the "informal sector" -- became increasingly common. While there are differences of opinion over the use of this term, it is used by many economists and other social scientists, and may be statistically delineated. Despite difficulties with certain aspects of the term, largely as a result of the fact that it represents a very diverse set of activities, an important recent study argues that:

Typically, enterprises with ten or more workers tend to function within the formal sector, while smaller enterprises (down to a single person) tend to function more informally. In any case, beginning in the 1970s, and gaining strength during the economic downturn of the 1980s and early 1990s, the urban informal sector has become a powerful force for employment creation in virtually all African cities.

Estimates made in the mid 1970s suggested "that in the typical African country the informal sector employs 60 per cent of the urban labour force." The estimates for urban areas within individual countries were as follows: the Congo, 55%; Senegal, 50%; Upper Volta (now Burkina Faso) 73%; Benin, 95%; and Niger, 65%. For individual cities, the figures were also high: Abidjan, 44%; Nairobi, 44%; Kumasi, 65%; Lagos, 50%; Banjul (The Gambia) 42%; Lomé 50%; Brazzaville, 37%; and Djibouti 20%.

Although good statistics are not available for the 1980s and 1990s, the proportion of the urban labour force in informal activities has almost certainly risen. A leading Ivoirian sociologist estimated that, between 1976 to 1985, the number of people "working on the street" in a variety of informal activities had risen from 25,000 to 53,850 in Abidjan alone. During the same period, the central government complement in Abidjan rose from 31,840 to 56,940. "Given the negligible difference between the two", he argues, "one could conclude that the street offers as much employment and provides a living to as many people as the public service!" One of the trends of the 1980s and 1990s has been the supplementation by informal activities of formal sector jobs on the part of a large proportion of public sector employees. Although many informal sector workers are poor, this is by no means always the case as such activities as market trading, the operation of public transport vehicles, or the renting out of housing in informal neighbourhoods may involve considerable income. Nevertheless, in general there is a marked gap between formal and informal wages.

The growth of the urban informal sector, reinforced by economic stagnation during the 1980s and concomitant structural adjustment programmes which had the effect of reducing employment in the formal public sector, has had a number of visible effects on African cities. As noted earlier, the areas of informal housing increased, most of them on the outskirts of cities, adding considerably to the horizontal growth of urban areas and spreading existing services and infrastructure even more thinly on the ground. A second consequence is the growth of large open-air (often informal) markets throughout cities, with a consequent decline in formal retail trade, even in main downtown areas. Around these markets are thousands of unregulated petty traders, who often occupy adjacent streets and sell goods and produce on the sidewalk in front of the established (and licensed) retail stores. A third area in which informal activity plays an important role is mass transit, with more and more private buses and vans operating throughout African cities. These vehicles often serve areas of the city -- such as the peripheral extensions -- that are not well served by the public transport system. Finally, rather substantial areas of African cities have developed into specialized quarters for informal activities, although there is also considerable dispersion of individual informal trades. The increasing physical presence of informal activities in African cities is having a major effect on the organization of space, as African cities distance themselves from their original colonial planning models.

DETERIORATION IN SERVICES: As African cities continued to increase in size during the 1980s and 1990s, their declining economic situation led to a precipitous decline in the supply of basic infrastructure and urban services. In many African cities, most refuse is uncollected and piles of decaying waste are allowed to rot in streets and vacant lots. Schools are becoming so overcrowded that many students have only minimal contact with their teachers. A declining proportion of urban roads are tarmacked and drained, and many that are not, turn into virtual quagmires during the rainy season. Basic drugs -- once given out freely -- have disappeared from public clinics and professional medical care is extremely difficult to obtain, except for the rich. Public transport systems are seriously overburdened; and more and more people are obliged to live in unserviced plots in "informal" housing, where clean drinking water must be directly purchased from water sellers at a prohibitive cost, and where telephones and electrical connections are scarcely available.

The lack of investment in urban infrastructure and services also inhibited economic expansion. This was demonstrated in a study of Lagos that found that:

Studies in other cities also show serious declines in public investment in infrastructure and services. For instance, in Togo, a study of urban investment levels in the four five-year plans spanning the period from 1966 to 1985 shows a steady reduction from 17.9% of total investment in the first plan, to 16.7% in the second plan, to 10.6% in the third plan and 6% in the fourth plan. This pattern, which appears to reflect a similar tendency in other French-speaking countries, may be connected to a decline in French overseas aid funds, both in absolute and relative magnitudes during the same period. In Dar es Salaam, there was a decline in expenditure on services and infrastructure of 8.5% a year from 1978/79 through 1986/87, measured in constant currency units. If Dar es Salaam's population growth is taken into account, the per capita decline in expenditures comes to 11% per year over the period studied. While the Tanzanian economy as a whole was stagnating during much of this period, the decline of the urban infrastructural fabric was occurring at a much more rapid rate. To the north, Nairobi's services have also been deteriorating along with its revenue base. The capital expenditures of the Nairobi City Commission (in real US dollars per capita) for water and sewerage fell from $27.78 in 1981 to 2.47 in 1987; and per capita maintenance expenditures fell from $7.29 to $2.30 over the same period when calculated in a similar manner. Over a six year period, this represents an average annual decrease of approximately 28%, compounded, when both capital and maintenance expenditures are added together. Similar calculations for expenditures on public works over the same period show an annual decrease of 19.5%, compounded; and for social services an annual decrease of 20%, compounded. Such figures suggest an alarming decrease in the ability of a modern African city to service the needs of its population.

Two major urban services that have become increasingly overburdened in almost all African countries are waste management and public transport. For instance, in Nairobi, as the city grew both in population and spatially at a rate close to 5% per year, the resources available to the municipal government to maintain its existing fleet of refuse removal vehicles -- let alone to permit it to purchase additional vehicles -- were severely limited. In 1989, officials felt 100 refuse collection trucks were needed to effectively serve the city of over a million people but only 10 trucks were functioning on a daily basis out of a total fleet of only 40 vehicles. The number of functioning, operational vehicles fell steadily during the 1980s from a high of 86 in 1978. In Dar es Salaam, a study of the city's garbage collection vehicles showed that in 1985, some 20 functioning trucks (of which only 6 were considered to be "in good condition") were able to collect only about 22% of the estimated 1200 tonnes of garbage produced every day. The situation was remedied somewhat with the donation of a number of vehicles by the Japanese government, but a study in 1988 showed that with 33 functioning trucks now on the road, the city council was only able to increase its waste removal efficiency to 28% of the estimated total of refuse produced daily. While the proportion of wastes collected varies across the continent, it remains a severe problem in almost all countries.

Just as the urban poor, who tend increasingly to live in peripheral, unplanned settlements are only sporadically served by such services as water supply, refuse removal and electricity supply, their marginal location and low disposable incomes makes them more vulnerable to difficulties in public transport supply. The situation in most African cities in the 1960s and 1970s was one of monopoly supply, whereby a public (or publicly contracted) bus company organized the mass transport system throughout the whole of the municipality. Some of these companies were very large: for example, the SOTRA in Abidjan (a "mixed" private company with both French and Ivorian shareholders) had a fleet of 1179 vehicles, and a staff of 6,153 in 1989; the SOTRAC in Dakar (also a "mixed" company) had a fleet of 461 vehicles and a staff of 2,871 in 1989. While these and other large companies such as KBS in Nairobi and Zupco in Harare represent some of the larger and more successful companies, by the 1980s, the system was breaking down, as many city administrations could not afford to replace, let alone properly maintain their ageing bus fleets at the same time as the population was growing; and even the private companies (operating in many Francophone countries) were having difficulties maintaining an efficient service in the face of declining revenues. A more mixed service, involving large public or private companies on the one hand, and a variety of smaller operators offering service on routes not otherwise covered by the larger companies, emerged. By 1989, informal privately operated cars, pickup trucks, minibuses or minivans had captured much of the public transport market in many cities.

In spite of the considerable increase in market claimed by the small operators vis-à-vis the large transit companies, and the improved accessibility to the city which they have brought to many low income groups, there are drawbacks that are constantly being discussed in the African press. Overcrowding is common; accidents appear to be much more frequent than in the public buses (particularly on peri-urban roads and highways), and the fare may even be higher than in the public system for the same, or similar routes.

The examples of waste disposal and public transport illustrate two dimensions of the current crisis of urban services in Africa. In the case of waste removal, in many cities, the inhabitants have been living through an absolute withdrawal in the level of public service provision, without alternatives being provided -- even at a lower standard of performance -- by the private sector. Private services are being provided in some cities, for a fee to the householder, and there is more work for scavengers and small recyclers, but the absolute evidence of efficient garbage disposal in many cities has declined rather dramatically since the 1970s. In the case of public transport, a much greater variety of modes of service has quite clearly developed with the decline of the large public companies.

However, the potential for private investment to substitute for public investment in infrastructure and services varies considerably, according to the infrastructural or service component in question. Thus, while the decline in public support for piped sewerage and treatment, port and airport facilities, urban roads, and electrical transmission facilities cannot easily be compensated for by privatisation, the same is not -- at least in principle -- the case for urban transport, airport services, non-piped water services and waste collection (if not waste disposal). As the state disengages from responsibility for providing a whole range of local services, and the urban population continues to grow, a new balance is emerging between private and public activity.

DETERIORATION IN THE BUILT ENVIRONMENT AND ENVIRONMENTAL HEALTH: The deterioration in the built environment is sharply in evidence throughout most of urban Africa. As more of the urban population was forced to unplanned settlements on the outskirts of large cities, or into more crowded living space in an already deteriorating housing stock in the more established "high density" areas; as a lower proportion of the population had direct access to clean, piped water, regular garbage disposal and good health services, the quality of life for the vast majority of the population deteriorated during the 1980s and 1990s. This trend seems to have been accentuated by the effects of structural adjustment in many countries, according to which urban workers lost more than rural smallholders. Some demographers have even suggested that the decline in mortality rates that was clearly evident during the 1960s and 1970s may have slowed down in the 1980s. For example, in 1978 the mortality rate for infants and children stood at 112 per thousand in Abidjan, and 197 in the rural areas; but the census of 1988 recorded a figure of 120 for Abidjan (an increase), as against 191 (a decrease) in the rural areas. In general, in Abidjan as well as elsewhere, most indices of health show much higher levels in urban, as opposed to rural areas, although the differences may be declining with the economic downturn and a reduction in health and nutritional expenditures by both government and individuals.

Under these conditions it may not be surprising to learn that in the central districts of Brazzaville there is less than one infectious mosquito bite per person every three years; by contrast, the rate is more than 100 times higher in the new informal settlement areas with low population density. In Bobo-Dioulasso, the second largest city in Burkina Faso, the measured rate of malaria occurrence measured in a peripheral neighbourhood was almost twice as high as that measured in a central section of the town.

Although urban agriculture has considerable importance in many Asian and Latin American countries - and also in certain cities in the North - it probably has the greatest importance in African urban centres as an important supplementary source of livelihood or of food and fuel for many more. Chapter 12 will return to its current and potential role; here, the aim is to illustrate its importance for urban populations in Africa.

A major study of six towns in Kenya (including the capital, Nairobi) was undertaken by a research NGO, the Mazingira Institute in the mid 1980s. The study sampled 1576 households on a wide range of economic activities and consumption habits. The data show that 29% of all households grow food within the urban area where they live; and 17% keep livestock. Extrapolating on their survey, the authors estimated that, in 1985, 25.2 million kg. of crops worth some $4 million were produced in urban areas in Kenya in one season. Most of the urban crop and livestock production was consumed as subsistence by the households themselves. Reflecting similar findings to the Kenyan study, a survey of research on urban farming in Zambia finds that most urban farmers are poor women, who grow food because of the failure of incomes to keep up with prices. A later study of Nairobi based on a different sampling strategy (the sample was chosen from those working on the land rather than randomly from urban households in the city) found that 64% of the respondents were female (very similar to the earlier Mazingira survey); that they tended to have only primary education, or no education at all; that most were born outside the city, in neighbouring districts; and that very few actually sold their crops. The pattern of poor women practising urban agriculture in order to provide food for themselves and their families is also a major finding of a study of 150 urban farming households in Kampala, Uganda. While the study deals with households rather than individuals, most of those who worked in the fields were women; the households themselves were predominantly (73%) at a "low level of income"; 69% were producing food primarily for household consumption and not sale; and the main crops grown were annual tuber crops (such as cassava, sweet potatoes, bananas and cocoyams) as well as maize and beans. Interviews with the producers in 1989 indicated that, on average they had been farming for 13 years and that the vast majority had begun the practice in the 1970s or early 1980s. This suggests very strongly that urban farming as a major activity developed in Kampala "in response to the declining economic situation. The farmers had been living in the city a long time before they started their agricultural enterprises." Across the continent in Lomé, a study of the agricultural aspects of urban farming -- while not comparable to work in East Africa -- observes that most of the market gardeners are men, and that very large sections of public land reserves on the periphery of the city are under cultivation, with the tacit approval of the authorities. While market gardening increased in Lomé as a direct response to the economic difficulties beginning in the late 1970s and early 1980s, produce is sold commercially rather than consumed by the cultivators. One of the effects of increasing urban agriculture in Africa is that the economic and cultural differences between city and rural areas have become blurred. This is particularly the case in peripheral, unplanned areas where formal infrastructure is scarce, and many households live in relatively large plots of land in a semi-rural environment.