After a few decades, the fertility rate also fell, reducing the rate of growth. This change from high to low fertility and mortality is known to demographers as the demographic transition . Unfortunately, it has not proved easy to reproduce this transition elsewhere. Mortality control is relatively easy to achieve, but fertility control relies on a shift in the behaviour of whole populations and has proved much more difficult. Economic prosperity alone is not sufficient, as shown by high fertility in the oil-rich states of the Middle East.
Compulsion is only partially successful, as shown by experience in China and India.
Provision of contraceptives has limited effects unless people are committed to their use. Education and the changing status of women are part of the pattern. A shift from a way of life where children support their parents in old age to one where parents support their children through a long period of education may be the decisive one. But, such is the variability with which fertility and mortality have changed in different countries, predictions are very difficult. They are even more difficult when many countries have populations growing faster than their rate of economic growth so that income per capita is falling.