Figure 4. Population Distribution by Age and Sex, 1982

Source: Based on information from Chad, Ministry of Planning and Reconstruction, Tchad: Relance economique en chiffres, N'Djamena, Chad, 1983, 15.

In the late 1980s, demographic data for Chad were very incomplete. One of the most important demographic techniques is projection from one set of data to anticipate the evolution of the population, but the lack of a national census in Chad has made applying such a technique difficult. In addition, population projections assume that the population has evolved with regularity since the last collection of data. In Chad, domestic conflict, foreign military occupation of part of its territory, and serious famines, from 1968 through 1973 and in the early 1980s, have disrupted the regular change of the population. As a result, many population estimates were probably inaccurate. In 1988 most population estimates continued to be based on projections from partial studies made in 1964 and 1968 by the National Institute of Economic and Statistical Studies (Institut National des Etudes Statistiques et Economiques--INSEE) in France and by the Chadian government. These survey data, projected forward, were the major reference sources for the Chadian government and for many international agencies and foreign governments. Two organizations, the Sahel Institute (Institut du Sahel--INSAH) and the Population Reference Bureau (PRB), gave different figures for Chad's population in 1985. The first organization estimated the population at almost 5 million the second, at 5.2 million. In the late 1980s, cognizant of the need for demographic data for planning, the Ministry of Planning and Reconstruction and the United Nations Economic Commission for Africa began planning the first national census for 1989.

Estimates of total population acquire greater meaning when the processes behind them are examined more closely. Population change is the sum of two sets of additions and two sets of subtractions. First, there are additions through births. In mid-1987 the PRB estimated Chad's birthrate at 43 live births per 1,000 inhabitants annually (the world average was 28 in 1987). The same organization suggested that, on average, Chadian women gave birth to 5.9 children over their reproductive years, a slightly lower number than the 6.3 average for Africa women as a whole.

Second, there are additions through immigration. Although ethnic, political, and economic ties connect most regions of Chad with neighboring states, such links probably have not brought a large number of permanent immigrants. By the late 1980s, Chadians who had fled the civil strife in the southern and central parts of the country during the late 1970s and early 1980s apparently had returned in large numbers. Nonetheless, overall immigration probably has not exceeded emigration.

Subtractions for population decrease also are calculated for two sets of events. First, there are subtractions through deaths. In the mid-1980s, the PRB estimated Chad's mor 1000 rtality rate at 23 deaths annually per 1,000 inhabitaÍÍÍÍÍÍÍÍnts--one of the highest mortality rates in the world (the global average stood at 10 in 1987). Civilian and military deaths, resulting from warfare, poor health conditions, and drought undoubtedly have contributed to this high mortality rate. The yearly infant mortality rate (the number of children per 1,000 births who die before age one) was also extremely high in Chad, estimated by INSAH and the PRB at 155 and 143, respectively. Among children, a second peak in mortality occurs after weaning (from about one and one-half to two years of age), when they are deprived of their mothers' natural immunities. High mortality rates are indicative of short life expectancies. In Chad, INSAH estimated the life expectancy for a female born in the period 1975-80 at 43.4 years for a male, it was even lower--38.5 years.

Emigration is the second form of subtraction. Although the data for Chad were partial, labor migration and refugee flight were the two major types of emigration. In recent decades, some of the old labor migration streams have continued, such as that to Sudan, and newer ones have joined them, such as those to Nigeria and the oil-rich countries of the Middle East during the petroleum boom of the 1970s and early 1980s.

Since independence, refugee flight has been a major component of emigration. In the late 1960s, troubles in eastern and southeastern Chad provoked emigration to Sudan. Patterns of flight have shifted with shifts in the theater of conflict. Following the battles of N'Djamena in 1979 and 1980, many residents sought refuge across the Chari River in neighboring Cameroon. Violence against southerners in N'Djamena brought further emigration, and the de facto partitioning of the country during the early 1980s brought retribution against northern merchants living in the southern cities of Moundou and Sarh. Although some of these people later returned to their homes within Chad, others sought refuge in Cameroon, Nigeria, and Central African Republic some members of the bourgeoisie and intelligentsia fled to Western Europe. In the 1980s, the conflict shifted north, where the Chadian and Libyan armies clashed repeatedly. These campaigns marked a major escalation in violence and probably provoked flight as well (see Civil Conflict and Libyan Intervention , ch. 5).

As a population, Chadians were quite young (see fig. 2). The PRB estimated that 44 percent of the population was younger than fifteen in 1987. Only 2 percent of the population was older than sixty-four. These percentages are best appreciated as components of what is called the dependency ratio--the combined percentage of people less than fifteen and more than sixty-four, who, because they are considered only marginally productive, must be supported by the remainder of the population. Although some social scientists and development analysts challenge this conventional definition, pointing out that in rural Africa and urban shantytowns children may indeed add to the household income, most demographers agree that the measure is nonetheless a good general indicator of the dependency burden. In Chad, then, the 46 percent of the population less than fifteen and more than sixty-four essentially had to be supported by the other 54 percent. Although this ratio was not the highest in Africa, the level of dependency was difficult for Chadian society to bear, in part because poor health and inadequate nutrition already took such a high toll among the working population, and because mechanization had not raised productivity.

In terms of the sex structure of the population, the 1964 INSAH survey calculated that there were 90 males for every 100 females in urban centers, the male percentage of the population rose slightly, to 96 for every 100 women. A small part of this imbalance may be attributed to higher male mortality rates, but male labor migration is probably a much more important factor. The absenc b75 e of a census or more recent demographic surveys made it impossible to determine if the Chadian Civil War had affected the sex ratio.

In the late 1980s, Chad had a low population density of about 3.8 people per square kilometer. The population was also very unevenly distributed because of contrasts in climate and physical environment. The Saharan zone was the least densely populated. In 1982 it was estimated to have a population density of 0.15 per square kilometer. Most inhabitants of the region lived in its southern reaches, south of 16° north latitude.

The sahelian zone had a population density of seven persons per square kilometer in 1971. Within the region, broad spectrums of rainfall and environment and the diverse life-styles that accompany them have resulted in widely varying population densities, from very low among the nomads in the northern regions to much higher among the agricultural populations in the south.

The highest population densities--about thirteen people per square kilometer--occurred in the soudanian zone. In 1971 almost 45 percent of the total Chadian population lived in this region. Chad was quite rural. The PRB placed the urban population of Africa at 31 percent in 1985, whereas Chad's urban population was estimated at only 22 percent. Although the urban population remained relatively small, urbanization accelerated in the 1980s. Whereas in 1971 only seven centers had more than 10,000 inhabitants, INSAH estimated that by 1978 nine cities had populations of more than 20,000. From a total of 132,502 enumerated in the urban census of 1968, N'Djamena's population grew to 150,000 in 1971, nearly doubling to 280,000 in 1978. Although much of the population abandoned the city during the battles of 1979 and 1980, most people returned over the next several years. In 1983 the Chadian government predicted that urban growth would continue at an annual rate of 7.8 percent for the capital and 4.6 percent for secondary cities such as Moundou, Sarh, and Abéché.

Data as of December 1988