THE BIRTH-RATE DECLINE IN DEVELOPING-COUNTRIES

Birth rates are falling in much of the developing world. In the mid-19 60s women in Asia, Africa and Latin America gave birth to an average o f six children. Today, the average is about four-a drop of one-third. In some regions and countries the average is substantially lower, appr oaching levels in the developed world. This remarkable decline in birt h rates is no cause for complacency about rapid population growth, how ever, as the Look at it this way article in this issue, by Catley-Carl son, rightly observes. Average family size is still well above the 2.1 'replacement level'-the number of children per couple that over the l ong run leads to zero population growth because each couple has only e nough children to replace itself in the population. Thus world populat ion, already about 5.5 billion, continues to grow. Even as the average number of children born per woman falls, population will continue to grow rapidly for many years because the number of women of childbearin g age is rising as a result of previous high birth rates-a phenomenon that demographers call 'population momentum'. That the world's populat ion is growing larger in a hurry is not news. But it is something of a surprise to learn that birth rates have declined so rapidly in so man y countries, including some that experts considered too poor and tradi tional for this to occur. In fact, birth rates have fallen much faster than experts expected. The Demographic and Health Surveys (DHS) and s imilar family planning surveys conducted in more than 40 developing co untries since 1985 tell the story of this striking decline.