Sub-Saharan Africa (48 states, 50 countries'", 700 million people in 2004, and close to 22 million sq. km.) was long considered by demographers to be a relatively homogeneous region that withstood the sociodemographic changes that had been occurring in a large part of the world since the 1950s or the 1960s. During the 1970s, African demography or the population of Tropical Africa was characterized overall by early and universal marriage, high fertility and excessive mortality, and finally rapid growth. Since then, however, the situation has changed, and Africa is no longer an exception. For the most part, it has entered the demographic transition process.
But just as elsewhere two or three decades ago, the changes are occurring at various paces according to the country, depending on the (numerous) cultural systems, the diversified economies, the political systems, but also on the crises of various kinds that some countries, or even entire sub-regions of the continent, have been experiencing over the last 30 years: conflicts and civil wars, food shortages that sometimes attain the famine stage, a deterioration of living standards, and of course AIDS. Vulnerability, insecurity and poverty are the fate of many countries, and of large strata of the population within each of them.
In the 1990s the demography of Africa and its sub-regions and countries became the subject of several general surveys. These were mostly collective works with a focus either on all the components of demographic change, or more often on one or the other issue, such as fertility or AIDS(2). The present chronicle, which is by definition less ambitious, has two objectives. The first is to present data that are as comparable, reliable and recent as possible on the evolution since 1950, and the present characteristics of the population of each country. These data are gathered in a statistical appendix in 14 large tables that correspond to each of the issues addressed in the text. The second objective is to achieve a synthetic view of the major components of change and of the growing diversification of the situations in the region. The information is summarized in graphs and smaller tables. This chronicle focuses on sub-Saharan Africa, and excludes the five countries of North Africa, which have a different history, culture and demography. Together with the Middle East, North Africa will be the subject of a future chronicle.
We begin with a few words comparing the African social and economic context with that of other regions, a review of the progress achieved in the area of information systems and an overview of the evolution of the population over two millennia. Next we consider successively: 1) the size and growth of the populations since 1950; 2) the sub-regional patterns of demographic transition; 3) nuptiality (age at first marriage, polygyny, marriage dissolution); 4) fertility (levels, trends) and its proximate determinants (e.g. breastfeeding, abstinence, contraception); 5) overall mortality, maternal mortality and AIDS; 6) child mortality (from age O to 5) and health (vaccination, malnutrition, medical services); 7) the age structure; 8) urbanization and the rural exodus; 9) international migration within Africa as well as to the wealthy countries; and 10) inequality between men and women in education.
Our approach is essentially descriptive, and involves the study of levels and trends in all countries and sub-regions, the discussion of inequality (in terms of education and type of residence) in countries at different stages in the transition or the process of development (particularly Benin, Nigeria, Mali, Cameroon, Kenya and Zimbabwe). Occasionally we will study the relation between the countries' demographic indices and various indicators of social, economic, human and health development, which are regrouped by country in Tables A. 13 and A. 14 of the Appendix.
The preferred sources of data include, on the one hand, the data banks of various United Nations agencies (the Population Division, UNDP, WHO, UNESCO, etc. …