Global birth rates have fallen very substantially in past decades but the difference in fertility between developed and developing countries is still wide.
High birth rates still constitute a characteristic of developing countries. In the more developed regions, an average woman now bears between 2 and 3 children, while in the developing regions she gives birth to between 2 and 7 children.
In the 1980s, the picture presented was as follows:
1. In more developed regions combined, the birth rate may have averaged 38 per 1,000 during 1850-1900 and 26 per 1,000 during 1900-1950, the average having fallen progressively as one region after another underwent this process of change. Post-war 'baby booms' led to an average birth rate of 23 per 1,000 in 1950-1960, subsiding to 19 per 1,000 in 1960-1970 and 15 per 1,000 in the last decade. Yet during all those decades, the average birth rate in the less developed regions combined is estimated at 40 or 41 per 1,000; and only in recent years, has this dropped to a still high 33 per 1,000. It is assumed that the annual average birth rate of the more developed regions will continue to fluctuate around 15 per 1,000 to the end of the century, whereas, during the same period, the average birth rate of the less developed regions may decrease even more decisively.
2. While the more developed regions tend towards greater uniformity in the level of crude birth rates, a wide range of conditions seem to exist in the less developed regions. Among 22 countries of these regions, the crude birth rate around 1970 was reported as less than 30 in 7 countries, 30-40 in 6 countries, 40-50 in 6 countries, and above 50 in 3 countries. More recent statistics indicate Africa, as a continent, having 46 per 1,000 as a birth rate; Latin America having 31, and Asia, 30. The wide ranges on each continent continue, however. If China is excluded from the figures for less-developed countries, then the average is 37 per 1,000.
The extremely low levels of fertility in Western consumerist cultures is associated with the separation of sexual relationship from marriage; the increasing tendency to regard sex as a form of recreation to which no consequences should be attached; and the view of children as expensive distractions from other competing demands on our resources. If third world birthrates are to fall to the levels which are regarded as acceptable in the West, it will be necessary to export to them that rag-bag of philosophy, laws and social policies which we call "the permissive society" – abortion and divorce on demand, the promotion of homosexuality, the provision of contraception to teenagers and the use of the educational system to instruct them in the techniques of promiscuity.
Only in the countries of sub-Saharan Africa does fertility remain well above the replacement rate. In the DRC, for example, the average woman still bears more than 6 children. But there, too, fertility is expected to plummet in the coming decades. The global Total Fertility Rate (TFR), according to the UNPD’s medium-variant projection, will fall from 2.3 in 2021 to 1.8 in 2100. The differences in estimates of when we reach peak humanity largely hinge on how quickly demographers think family size will shrink in Africa.