Kenya's plans for its children.

• Author: Chege, Nancy

I always knew that my high school friend Janet belonged to a big family, but it wasn't until she invited me to her house one Saturday afternoon that I realized how big. Hanging over the mantle-piece was a large framed picture. There sat Janet's parents amid a crowd of children: Janet and her fourteen siblings.

Fifteen children is a big family even in Kenya, a country that as recently as a decade ago was thought to have the highest population growth rate in the world: 4 percent. Since 1948, when Kenya's first census was taken, the population has grown from 5 million to 26 million--a staggering fivefold increase. In the early 1980s, experts both inside and outside the country were predicting growth of the same magnitude for several more decades.

That's why the 1989 Demographic and Health Survey came as a shock. The DHS, produced by the U.S.-based consulting firm Macro International and Kenya's National Council for Population and Development, showed that the country's total fertility rate--the average number of children a woman will bear in her lifetime--had declined from 8.1 to 6.7. The 1993 DHS showed a further decline to 5.4. A 33 percent drop in the rate over the course of only 15 years is one of the most precipitous declines ever measured. Kenya's population growth rate had started to fall: it now stands at about 3 percent. What lay behind the changing numbers?

Kenyans had always had large families. Only a few decades ago, a high child mortality rate meant that parents had to have many babies, to insure the survival of some. But it wasn't just a matter of survival: marriages were polygamous, and family size reflected the affluence of the father. A large family was the mark of a wealthy man--one who could pay the substantial dowry required for each wife, and support all their offspring.

Two of my great grandfathers were apparently rather affluent: one had eight wives, while the other had 12. In the traditional economy, children were regarded as an unqualified blessing--as a source of free labor that would allow a family to cultivate more land or raise a bigger herd. Large families were a kind of pension as well, a way of guaranteeing the parents comfortable care in their old age.

But traditional society has been reshaped by western influences. Western medicine, for instance, has radically reduced child mortality rates. In 1963, the year Kenya won independence from Great Britain, more than 120 of every 1,000 babies failed to see their first...