A moderate of population excess.

A moderate view of population excess

Ever since Malthus, economists have been unable to look at populations without multiplying in their heads. But the matk keeps giving different answers. Recently, "market theorists" have challenged the pessimism of ecologically oriented projections of world polulation growth, arguing that the demands of growing populations can bring advances that counter the tendency toward depletion of resources (SN: 10/17/81, p. 245). Into the midst of the debate, the National Academy of Sciences (NAS) last week released a report that takes the middle ground.

The NAS committee looked at the effect of population growth on the economies of developing countries, focusing on such issues as resource degradation and exhaustion, distribution of capital, positive effects of technological innovation and economies of scale, and quality-of-life indicators such as levels of schooling and health. In most of these arenas in such countries, the report concludes, slower population growth would improve well-being. But the authors take a moderate view of the hazards of growth, giving much greater weight than earlier studies to the adaptability of institutions and individuals.

"The rate of population growth is an important variable, but there are many other variables that can have a greater effect on people's welfare," says D. Gale Johnson of the University of Chicago, a member of the NAS working group on population and economic development. For instance, urban bias in developing countries can leave rural areas without roads or access to goods; or a decision to tax crops destined for export can dissuade farmers from planting -- and "people can change that," Johnson told SCIENCE NEWS.

With population in developing countries growing at an average of 2 percent each year -- doubling in numbers every 35 years -- some would have preferred a stronger statement from NAS. "I have no doubt that the world can accomodate a 1 percent growth rate for the next 100 years, with no problem," says Hans Binswanger of the Washington, D.C.-based World Bank. "Countries that are growing ... at a 4 or 5 percent growth rate would need agricultural miracles" to avoid extreme declines in income and living standards, he says. "All policies have to be right and governments have to be wise and all goals have to be achieved. And that's a lot to ask."

Lester Brown of the Washington, D.C.-based Worldwatch Institute puts it more strongly. "There will be adjustments [in population growth rates]; I don't think there's any question about that. The question is whether those adjustments will take the form of declining birth rates or rising death rates."

Because of its measured tone, though, the report may be taken more seriously by the market-oriented Reagan administration, and it may well increase support here for international family-planning programs, some observers believe. Ben Wattenberg of the-American Enterprises Institute in Washington, D.C., says, "I would argue that from realism -- and I regard this as a profoundly realistic document -- flows credibility. And from credibility flows money."