World population implosion?

Public Interest, Fall, 1997 by Nicholas Eberstadt

To address such questions, we might begin by examining the available research on health and aging. That literature, as it happens, is inconclusive - or more precisely, it points in opposite and mutually exclusive directions. According to one school of thought, the risk of illness and mortality changes are inversely related: Longer lives mean worse health for the survivors. The other school holds that improvements in life expectancy translate into greater life expectancy free from disability, even for persons in their seventies and early eighties.

Reviewing the points of controversy in these studies, one is inevitably struck by the mischievous ambiguity of the term "healthy life." "Mortality" is easy to define and thus (in theory) to measure; not so with "health," which has many gradations and is subjective anyway. It is possible, and indeed likely, that existing data on self-perceived health status are confounded by the higher expectations of those who are better off: In the United States and elsewhere, despite physical evidence to the contrary, more affluent and better educated people often seem more inclined than their less well off peers to rate their own health as unsatisfactory.

The international data, however, would seem to support the argument that improvements in "disability-free" life expectancy occur nearly as rapidly as improvements in life expectancy itself - at least for the population under 85 years of age and so long as "disability" is carefully and objectively defined. Indeed, proper health habits and appropriate medical help can already offer the great majority of persons the possibility of active and independent life well into their eighties. To this extent, anxieties about the coming of an era of dependent invalids would appear to be misplaced.

At the same time, we should remember that the quality of life for older persons may at times hinge upon discrete, but expensive, medical treatments. Insofar as such services would be more available in rich countries than in poor ones, even in the year 2050, differences in the health status of the elderly might in the future provide the same sort of summary index of "development" that the infant mortality rate is today taken to offer.

Economic performance

In the 1930s, when the specter of "depopulation" haunted Western intellectuals, many of the most eminent economists of the day - including Alvin Hansen, Roy Harrod, John Maynard Keynes, Gunnar Myrdal, and Joan Robinson - argued that low fertility and stagnant or declining population could compromise economic performance. By stifling demand, sluggish or negative population growth could exacerbate, or even precipitate, "underconsumption" - and a crisis of unemployment. At the very least, low fertility would press down the investment rate or slow the allocation of new labor into promising and productive areas.

With the benefit of hindsight, most of these arguments now look surprisingly weak. Depression-era economists were too ready to explain that great international slump - which was essentially non-demographic in nature - in terms of the fertility patterns and population trends of the day. (Ironically, barely a generation later eminent economists were attributing those same ills to overly rapid rates of population growth.) And the economists of the 1930s underestimated the role international trade might play in linking (and thus expanding) markets and in stimulating a productivity-enhancing division of labor, regardless of the population trends in a given country at a given time.