Commentary: The Population Fizzle
Anne H. Ehrlich

The population explosion is in the news again--this time as a non-event, according to conservative writers. As the United Nations prepares to issue its next demographic projections, reportedly being revised downward again, the new doomsayers (who have long claimed that overpopulation was a myth or an impossibility for such a resourceful creature as Homo sapiens) are raising alarms about imminent population shrinkage. The opening salvo was fired by Stephen Mosher in the Wall St. Journal last February, anticipating economic disaster from an aging population with too few children. Mosher's alarm has been topped by demographer Nicholas Eberstadt's op-ed in the Wall St. Journal, "The Population Implosion." Additional contributions on the same theme have appeared in diverse publications, including The New York Times.

Eberstadt bases his concerns on the UN's 1996 revision of its World Population Prospects, one of the oldest, most complete, and respected series of demographic projections. The projections usually are presented as a set of three (high, low, and medium) variants that are thought to encompass the likeliest trajectories that the global population will follow for the next century or so. Of course, the UN demographers think that the actual demographic path will fall closest to the medium projection, which in the 1996 series showed the global population passing 9.4 billion around 2050, still growing. But Eberstadt's attention focuses on the low variant, which the demographers think has a relatively low probability of being followed. The low variant postulates an end to growth by 2040 at about 8 billion, followed by a slow decline in numbers as deaths exceed births. Presenting this as if it were the inevitable fate we face, Eberstadt paints a truly dismal picture of the future, a population dominated by doddering old folks with scarcely a child to be found. (As an incipient old person, I take some exception to the implication that elders are hopelessly unable to take care of themselves.)

To dramatize the point, Eberstadt presents a chart showing crossing trend lines for percentages in the population of children under age five and people over 65 from 1950 to 2050, calculated from assumptions of extremely rapidly dropping fertility. The lines cross around 2015 at about 7 percent. The percentage of under five-year-olds, having hovered around 15 percent in the 1950s and 1960s, plummets to 4 percent, while the elder population soars from 5 percent to 18 percent (increasing life expectancy is part of this picture, of course). The comparison is very misleading because the under five age class includes only five ages, whereas the elderly category includes people aged from 65 to 100 years. A comparison of the elderly cohorts with those under age 15 would have been considerably more reasonable, if not nearly as dramatic. Since many developing countries have had (and some still do) percentages of their populations under 15 (who are mostly economically dependent) as high as 45 or 50 percent, a trade-off of fewer children for 18 percent over 65 (who are not necessarily dependent) doesn't seem all that daunting.

Furthermore, Eberstadt asserts that, after reaching its peak size by 2050, the world population will immediately begin shrinking by some 25 percent per generation, based on an assumption that the populations of most developing regions will have acquired the lowest fertility patterns now seen in developed nations: a total fertility rate (roughly equivalent to average family size) well below the "replacement" rate of 2.1. Italy's current record low total fertility rate of 1.2 is cited as an "extreme instance," then used to exemplify where we are all headed. Yet Italy's low fertility, which has only prevailed for a few years, very likely is partly due to deferment of births among young women now entering the workforce in large numbers -- a phenomenon that characterized the U.S. fertility drop 25 years ago, but led to a modest rebound a decade or so later.

Eberstadt deplores a demographic trend that will change family structures so drastically that (again using Italy as a model) most individuals will have no siblings, aunts, uncles, or cousins -- only ancestors. As a product of a small family for several generations myself, I don't feel especially deprived in this regard. Indeed, modern, highly mobile society has done far more in my perception than demographics to isolate individuals from regular contact with close kin. Eberstadt also threatens us with a changing balance of population between industrialized and developing societies, as though that weren't already an advanced process. Actually, rapidly falling fertility in the latter group will reduce the rate at which the gap would otherwise widen.

The predicted--and wholly predictable--economic consequences of negative population growth and an aging population structure are what concern the readers of the Wall St. Journal, of course, threatening the solvency of the social security system and pension programs, among other things. This is not even news, however; virtually all industrialized nations have been facing this issue for a decade or more. While it does present some serious problems (though most solutions are unpopular with voters), they are not insurmountable. Indeed, the availability of demographic information and projections gives societies several decades' lead time for finding and implementing solutions. Perhaps more important, today's developing countries may be able to avoid the pitfall of overcommitting tax-based provisions for their elderly as their populations inexorably shift toward an older age structure. At the same time, falling birthrates will relieve the burdens of schooling, health care, crime prevention, and other costs of supporting huge and growing numbers of children and young adults. Finally, of course, it must always be remembered that an aging population is mathematically unavoidable as population growth comes to an end. Only the innumerate can look to permanent growth as an answer to the social security crunch. In essence, the Wall St. Journal school of demography is simply recommending that we defer the problem for a few more generations, forcing our grandchildren to confront it in an even more overcrowded, resource-short, environmentally degraded world.

Some of Eberstadt's worries were echoed, but without resorting to extreme cases to illustrate the predicament, by Barbara Crossette in the New York Times. Her focus is on the developed countries, many of which have already made the transition to negative population growth. She quotes the director of the UN's Population Division, who expresses concern that NPG could undermine their leadership roles as producer, consumer, and donor nations, thus jeopardizing the stability of the world economy. The article points out that in 1975 only 18 percent of the world's population lived in countries with below-replacement fertility, a fraction that had risen to 44 percent by 1997 and is projected to reach 67 percent by 2015. Because of continuing high fertility in developing countries and the momentum of population growth that ensures continued growth long after birthrates have fallen, the world population expanded from about 4.1 billion in 1975 to 5.9 billion by the end of 1997, and is projected to reach 7.3 billion in 2015.

Now comes Ben Wattenberg with a similar prediction of doom in the New York Times Magazine, claiming that a new revision, further downward, is being prepared by the UN Population Division. In discussing the number by which the medium population projection for the year 2050 was reduced in the 1996 revision compared to that of 1994, Wattenberg asserts that "...demographers were caught with their projections up. Suddenly, worldwide, 650 million people were 'missing.' ....They will never be born." The forthcoming revision, scheduled for 1998, is expected to reduce the projected population even further. Wattenberg notes that the average worldwide total fertility rate (lifetime births per woman) fell from five in the 1950s to three in the early 1990s, and had dropped to 2.8 by 1997. As causes of lower fertility, he mentions urbanization, increased education and new aspirations for women, higher incomes, acceptance of homosexuality, availability of contraception and abortion, and falling infant mortality rates.

Wattenberg cites leading demographers as thinking now that the population's actual trajectory will fall somewhere between the 1996 medium and low variants: attaining a total fertility rate of about 1.85 and a peak population size of about 8.5 billion in 2050, poised to start declining. Once again the aging population is presented as the worst of all possible worlds. Wattenberg notes that, under this scenario, the proportion of people over 65 will rise from about 6 percent in 1990 to 15 to 19 percent by 2050, which he coyly calls a "grayby boom." Yet Japan and most European countries are already in that range, and their societies don't seem to be unduly burdened by it. Indeed, current and future generations of elders are and probably will be in considerably better health and more productive than earlier generations have been. Simply shifting retirement ages to later years would solve most of the economic problems. Nevertheless, the alarm being raised by the new doomsayers over possible population shrinkage in the future is being picked up and echoed in various other newspapers.

Is this really a picture of doom? To anyone concerned about the ability of Earth's life-support systems to sustain a multi-billion population of human beings, it plainly is not. The scientific community has spoken out clearly and firmly on the need to limit human population growth as "natural systems are being pushed ever closer to their limits." Even Wattenberg notes that a smaller future population spells good news for the environment, commenting that the global warming projections based on older projections of a global population of 11.5 billion in 2100 will need to be revised sharply downward. This is very good news. While the unanticipated rapidity of growth in economies and energy use in developing regions, especially China, may well offset the effect of reduced population growth, combining that trend with the previous population projections would have presented an even greater prospect of environmental disaster.

In any case, the population explosion is far from over. The world population is still growing by more than 80 million per year and will increase by another billion by around 2010. The new revision cited by Wattenberg nonetheless indicates expansion by 2.5 billion--a 42 percent rise--before growth ends and a decline can begin roughly two generations from now. Even that optimistic projection would mean the addition to the population of as many people as existed in 1950.

Somehow, during that prolonged further expansion, humanity must continue to increase production of food and mobilization of water and other resources required to support the additional people. Then and for many overpopulated decades after the peak population size has been reached, those increased levels of production must be maintained. All that must be accomplished without completely ravaging the natural resource base that makes it possible -- even though humanity is already living on and depleting its natural capital. Compared to that awesome task, adjusting to an aging population seems a minor problem at most.

Originally published in Ecofables/Ecoscience Vol. 1, No. 2, Summer 1998. An occasional publication of the Center for Conservation Biology, Stanford University.