Cover Image
close this bookReversing the Spiral - The Population, Agriculture, and Environment Nexus in Sub-Saharan Africa (WB, 1994, 320 p.)
close this folder3. The demographic dimension
View the documentThe lagging demographic transition
View the documentFertility and agriculture: Part of the Nexus?
View the documentNotes
View the documentAppendix to chapter 3

The lagging demographic transition

Sub-Saharan Africa lags behind other regions in its demographic transition The total fertility rate (TFR) for SSA es a whole has remained virtually unchanged at about 6.4 to 6 6 for the past twenty-five years (Table A-2) This is significantly higher than in other countries with similar levels of income, life expectancy, female education, and contraceptive prevalence. In a number of countries of Sub-Saharan Africa fertility in fact has risen (in large part due to significant success in treating diseases that cause infertility), while it has declined elsewhere in the developing world.

Recent statistics, collected through nationally representative sample surveys carried out between 1986 and 1989 under the Demographic and Health Surveys (DHS) Program,¹ appear to signal' however, that several countries are at or near a critical demographic turning point (Table A8).² In Botswana, the TFR fell from 6.9 in the mid-1960s to 4 7 in 1989, and in Zimbabwe it dropped from 8.0 to 5.3 over the same period. In Kenya, the TFR declined from 8.2 in 1977/78 to 7.7 in 1984 and to 65 in 1989 (Kelley and Nobbe 1990:33.). Encouraging, too, are the date from Nigeria which indicate a TFR of 5.7 in 1990, compared with 6 9 in 1965 In Cd'Ivoire Ghana, Mozambique, and Sudan, fertility also appears to have begun a secular decline (Table A-2).³

Life expectancy in Sub-Saharan Africa has risen from an average of 43 years in 1965 to 51 years in 1990 (Table A-1) In eighteen countries, average life expectancy today is 53 years or more Mainly due to the decline in mortality rates, population growth has accelerated from an average of 2.7 percent a year for 1965-1980 to about 3.1 percent a year at present (Table A-2). And, given the age structure of SSA populations, the momentum for continued growth is already built in. Even if the TFR were to drop immediately to the replacement level of 2 2 births per woman, it would take almost a hundred years before the population would cease growing. By then it would be 80 to 100 percent larger than it is today.

Figure 3-1 Total Population of Sub-Saharan Africa, 1960-1990

The high fertility rates, and the marriage, reproductive, and contraceptive behavior patterns that underlie these, arise in part from the fact at most women live in rural areas and have little or no education, few opportunities; outside their traditional roles, and limited legal rights. Childbearing enhances their status, and most women marry and begin having children early and continue to have them throughout their fecund years. But the comparative lack of urbanization and education does not explain everything: data available from the World Fertility Survey (WFS) for 1978-1982 indicate that urban and rural, educated and uneducated women in Sub-Saharan Africa have and want more children than their counterparts elsewhere.4

Women in Sub-Saharan Africa marry early: WFS data for the early 1980s show that, on average, 40 percent of all women aged 15-19 and 75 percent of those age 20-24 were or had been married (Cachrane and Farid 1989). Early female marriage increases the number of fecund years a women spends in union and therefore tends to exert upward pressure on the TFR. Even urban women in Sub-Saharan Africa marry earlier than rural women in North Africa and Asia (Cochrane and Farid 1989).

Contraceptive use in Sub-Saharan Africa is far below that in other regions (Tables A-5 and A 6). It is associated primarily with the desire for child spacing and only secondarily with the wish to limit family size (Table A-6). Use of efficient contraceptive methods generally increases with urbanization.5 Low contraceptive use is due in pert to poor knowledge. There are wide differences among countries, but on average, only about half of all women in SSA had, by the early 1980s, heard of a way (either efficient or inefficient) to prevent pregnancy. This compared with rates of 85 to 95 percent in other regions (Cochrane and Farid 1989). By the late 1980s, the DHS surveys showed measurable increases in the percentage of women who had knowledge of modern contraceptive methods: in ten of the twelve SSA countries surveyed and for which data are available so far, between 64 and 98 percent of currently married women aged 15-49 knew of at least one modern contraceptive method (the exceptions were Mali and Nigeria, with only 29 percent and 41 percent, respectively). The DHS data on contraceptive prevalence rates (CPRs) indicate, however, the difficult task ahead: only between 1 and 6 percent of these married women were currently using a modern contraceptive method, and the percentage of married women using any contraceptive method ranged only between 3 and 13 percent. The exceptions, with significantly higher CPRs, are Botswana, Kenya, and Zimbabwe (Table A8).

Box 3-1 Population Projections for Sub-Saharan Africa

Recent Bank projections assume that the TFR for Sub-Saharan Africa (including South Africa) will decline from 6.5 percent in the period 19851990 to about 3.25 percent by 2030. This implies average annual population growth rates of just over 3 percent in the 1990s, 2.9 percent in the following decade, and close to 2.6 percent in the decade thereafter. In this scenario, the SSA population would exceed 1,000 million by the year 2012 By the turn of the present century, SSA would be second only to Asia in terms of total population. Aggregate population growth will remain above 2 percent per year at least until 2025, by which time the population of SubSaharan Africa, at 1,378 million, would be 2.6 times that of today. The net reproduction rate (NRR) will decline to 1 only by 2060. And Sub-Saharan Africa would reach a hypothetical stationary population of over 3,100 million only some time after the year 2150 (Stephens and others 1991).

Among all groups of women, desired fertility is far higher in SubSaharan Africa than elsewhere. However, the WFS data analyzed by Cochrane and Farid also showed that (a) younger women desire fewer children than do older women; (b) urban women want fewer children than do rural women (although urban residence has not yet become a strong fertility depressant—the rural-urban differentials being smaller in SSA than in other regions); and (c) educated women want far fewer children than do uneducated ones

Box 3-2 Contraceptive Prevalence Among Women: Sub-Saharan Africa vs. Other Regions

Data for the early 1980s indicate that the percentage of women in SubSaharan Africa who had "ever used" any contraceptive methods varied widely-from 2 percent in Mauritania to 74 percent in Cd'Ivoire. The average for the ten SSA countries covered in the World Fertility Survey (WFS) was 26 percent, compared with 40 percent in both North Africa and Asia and 62 percent in Latin America. The regional comparison revealed far greater differences when only "efficient" methods were considered: only 6 percent of women in SSA had ever used these, compared with 32 to 50 percent of women in other regions.

Based on reported "current users," contraceptive prevalence in SSA was very low indeed, of both efficient and inefficient methods. In six of the ten SSA countries surveyed, fewer that 1 percent of all women were current users of modern methods. The difference between "currently using" and "ever used" was much greater in SSA than elsewhere, probably reflecting the comparatively much greater use in SSA of contraceptive practices for birth spacing, rather than for limiting family size (Cochrane and Farid 1989).

In Sub-Saharan Africa, as elsewhere, women's education affects fertility preferences, use of modern contraceptive methods, and fertility. Cochrane and Farid found that:

· There are considerable differences in desired family size among countries (see also Table A-8), but with increasing maternal education there is both a decline and a clear convergence across countries.

· Current use of any contraceptive method was only 4 percent among the least educated (compared with 19 to 34 percent in other regions), but 19 percent among the most educated (compared with 43 to 56 percent in the other regions).

· Although current use of contraceptive practices among the most educated women in Sub-Saharan Africa was only about the same as among the least educated in North Africa and well below the least educated in Asia and Latin America, even this low rate was sufficient to lower the TFR to about 5 for women with seven or more years of schooling.

Fertility rises with a few years of schooling, but then declines (as in other regions). But the effect of maternal education on fertility has been less pronounced, to date, in Sub-Saharan Africa than elsewhere.

The very high infant and child mortality rates (Table A-3) prevent achieving desired, or target, fertility levels—and this helps explain the low CPRs (Tables A-5 and A-6). Contraceptive use increases as the number of living children increases. Although infant and child mortality have declined over the past two decades (in some countries substantially), they remain much higher than in other regions (albeit with considerable differences among countries).6 Higher child survival rates reduce the need to replace children who have died or to have more children to insure against the likelihood of future deaths. Infant mortality rates are well below the SSA average of 107 in Botswana (36), Kenya (67), and Zimbabwe (48) . The same is true for child mortality rates, where the SSA average is 177: Botswana (403, Kenya (105), and Zimbabwe (57).

each of these countries, the TFR has begun to show a decline, signalling the onset of the demographic transition (Table A-8).

Infant mortality is highest in rural areas, and children born to young mothers are at greater risk. Infant mortality is also higher for first-born children and for those born seventh or later. Children's survival chances are greater if the interval from the previous pregnancy is longer (maternal attrition, lower risk of low birth weight' maternal attention). Infant and child mortality decrease consistently with the mothers' education. Urbanrural differences in infant and child mortality are significant and somewhat larger in Sub-Saharan Africa than in other regions.

Prolonged and near universal breastfeeding has been the main factor keeping fertility below a biological maximum in most SSA counties. The duration of breastfeeding is generally shorter in urban than in rural areas, but it does not decline as rapidly with mother's educational levels as in other regions. The most educated women in Sub-Saharan Africa breastfeed considerably longer than those in Latin America and Asia. Breastfeeding has important positive effects on child health and, indirectly, via reduced infant mortality, on fertility decisions. It also affects birth spacing—and thereby maternal health, infant health, and fertility. In this respect, postpartum infecundity is far more important in Sub-Saharan Africa than elsewhere, accounting for 59 percent of the reduction in fertility from the biological maximum. On average, fertility in SSA is only 67 percent of what it would be in the absence of breastfeeding.

Nevertheless, fertility patterns do not seem to be fully explained by the proximate determinants of marriage, postpartum infecundity (breastfeeding), and contraceptive use. Abortion, sterility, subfecundity, and spousal separation appear to suppress the "maximum" fertility below that observed in other regions This suggests the need for more research on other determinants of fertility to understand current levels and probable future trends (Cochrane and Farid 1989).

Figure 3-2 Infant Mortality Rate, 1960-1990