But despite the severity of the world demographic situation, the peak of the baby boom left behind. What happened? The answer to this question gives the theory of demographic transition, proposed back in 1945, the Western demografom f. Noutstojnom. In accordance with her level of fertility and mortality in General not due to biological and social conditions. The demographic transition refers to the process of progressive changes in fertility, mortality and natural increase as social and economic development of countries. Few simplifying the issue, it can be said that, according to this theory, overcrowding is a function of poverty. Even in the most conservative Islamic societies (for example, some who have grown rich oil exporting countries of the Middle East), "women having to civilization and luxury", do not wish to have any more children, for families with many children as would automatically lower their status in society, they get behind the wheel of a car, and so on.
The demographic transition involves four distinct phases.
Phase 1. High fertility and mortality, which makes its population nearly stable. This situation may occur when a very weak development of medicine.
Phase 2. Society must learn to control the disease, leading to high mortality rates. It has fallen dramatically, but the birth rate remains high, causing a rapid population growth.
Phase 3. Socio-economic transformations in the world lead to General reductions in fertility. At the end of this phase, the population again stabilizes, because the reduction of child mortality is offset by the low birth rate.
Phase 4. Low fertility and mortality rates have almost a constant level of the world's population.
Analysis of the demographic reality in the contemporary world shows that highly developed countries are now approaching the end of the third phase, while developing are at best in the early stages of this phase, in the worst — at the end of the second phase (some countries in sub-Saharan Africa).