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Bongaarts points out in the October 16, 1998 issue of Science
that contraceptive use in the developing world, once rare, is now widespread:
the average number of births per woman has fallen by half from the traditional
six or more to near three today. This "revolution in reproductive behavior,"
says Bongaarts, has led some to speculate that "the world population
explosion is over." But instead of being near the end of the "explosion"
with today's population of 5.9 billion, Bongaarts comments, "we are
just past its midpoint. After a record-breaking increase of 2 billion people
over the past 25 years, the same increase is projected over the next 25
years, and a further expansion to 10.4 billion is expected by 2100."
 Large increases in population growth
are expected in Africa, Asia, and Latin America for three reasons, Bongaarts
says. First, fertility is still about 50 percent above the two-child level
needed to bring about population stabilization. With more than two surviving
children per woman, every generation is larger than the preceding one.
Second, declines in mortality historically
the main cause of population growth will almost certainly continue. Higher
standards of living, better nutrition, expanded health services, and greater
investments in public health measures have increased life expectancy by
50 percent since 1950. The unhappy exceptions will be life expectancy declines
in most of those sub-Saharan African countries with severe AIDS epidemics.
Third, the historically largest generation of women about to enter the childbearing
years will produce more than enough births to maintain population growth
for decades even if they each have only two children population momentum. |
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Europe, North America, and Japan face quite a different
demographic future, Bongaarts says, along with such rapidly developing Southeast
Asian countries as Hong Kong, Korea, and Singapore, which also have experienced
steep declines in population growth rates since 1960. But because of immigration,
rising life expectancy, and/or population momentum, the populations in even
these countries are projected to remain close to current levels for several
decades, with modest increases expected (e.g. the United States) and small
declines (e.g. in Europe).
Bongaarts feels that concern about
underpopulation in developed countries has been exaggerated. Although observed
fertility has reached historic lows in many developed countries and the
percentage of women remaining childless is relatively high, it is likely
that birth rates will not drop further and may even turn up. To support
this conclusion, Bongaarts points to a puzzling discrepancy between expressed
preferences for family size and measured fertility in most low-fertility
societies.
In most low-fertility societies,
the preferred family size is about two children and the actual childbearing
experiences of women support this number, but this is not reflected in the
most widely reported measure of annual fertility (the so-called total fertility
rate). "The measurement of this fertility rate picks up a slightly
different picture than we get looking at women's actual reproductive histories,"
Bongaarts says. Women choosing to defer births to older ages temporarily
contribute to today's baby bust (which reflects the measurement of the number
of babies born each year), just as younger childbearing ages in the 1950s
temporarily contributed to a baby boom. If women in a given country have
the same number of children in their lifetime, but later in their lives
than their predecessors, this will appear to be a reduction in annual birth
statistics. Family size may in fact not be changing in nearly as dramatic
a fashion as is suggested by the year-over-year aggregate birth statistics.
"These distortions," comments
Bongaarts, "are temporary because they exist only while the age at
childbearing is rising. Once women stop deferring births, the distortion
disappears and the very low fertility rates observed in the developed world
should rise closer to the 2 children most couples want."
For example, in France the annual
total fertility rate has been reported to be well below the replacement
level since the mid-1970s. But in actuality, French women who have reached
the end of their childbearing years report having 2.1 births on average,
close to the preferred number. Similar discrepancies exist in many other
developed countries. In the United States, fertility rose from 1.77 to 2.08
births per woman between 1975 and 1990 as the postponement of births stopped.
It is therefore plausible to assume that fertility in Europe and Japan will
not decline further and might even turn upward soon. It is unlikely, however,
that fertility in these countries will rise all the way to replacement level
because various constraints (e.g. divorce, desire to remain employed, rising
costs of children, involuntary childlessness) prevent some couples from
reaching their desired family size. The most plausible pattern is the one
now assumed by the United Nations: a modest rise in fertility to a level
somewhat below replacement, with large population declines unlikely. |
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Policy implications for both conditions sizable population
growth in developing countries and below-replacement levels in developed
countries call for different approaches, Bongaarts says. Indifference is
not one of them. Concern over adverse consequences of additional billions
of people in the poorer countries has "provided the principal rationale
for past investments in voluntary family planning and reproductive health
programs that help couples avoid unwanted childbearing. This effort should
be strengthened and expanded to include social investments in young people
for example, girls' education that help offset population momentum and improve
the quality of individual lives."
In the developed world, the potential
adverse consequences of prolonged below-replacement fertility have led to
"extensive discussions but little action," with most governments
reluctant to pursue explicit pro-natalist policies. Numerous policy options
have been proposed to encourage childbearing, Bongaarts says, but, unfortunately,
there is "little useful experience to draw on in assessing potential
effectiveness. In rare instances where new measures to raise fertility were
successfully implemented (for example, Sweden in the late 1980s) it is difficult
to disentangle the roles of the specific components in a package of measures."
Options include free or subsidized child care, reduced taxes for families
with children, paid parental leaves, and subsidized housing for young couples.
John Bongaarts is Vice President,
Policy Research Division, Population Council. A noted demographer, Dr. Bongaarts
received two major awards from the Population Association of America and
an award from the National Institutes of Health. He is Chairman of the National
Academy of Science's panel on population projections.  |
The Population Council
is an international, nonprofit, nongovernmental institution that seeks to
improve the well-being and reproductive health of current and future generations
around the world and to help achieve a humane, equitable, and sustainable
balance between people and resources. The Council conducts biomedical, social
science, and public health research and helps build research capacities
in developing countries. Established in 1952, the Council is governed by
an international board of trustees. Its New York headquarters supports a
global network of regional and country offices.
For information, contact: Sandra Waldman, (212) 339-0525; Christina Horzepa, (212) 339-0520, chorzepa popcouncil.org. |
urrent trends in reproductive
behav- ior differ sharply between regions and should not be confused, says
Population Council vice president John Bongaarts. "In the already crowded
developing world, despite plummeting fertility rates, both the number of
births and population size will keep growing. The expected addition of several
billion more people will hamper ongoing efforts to reduce poverty and achieve
sustainable development. On the other hand, in parts of the developed world,
particularly Europe and Japan, already low fertility is causing consternation
over the potential adverse effects of an aging or declining population.
This concern should not be overblown, however, since reported fertility
measures do not reflect the fact that couples are still having about two
children they're just having them at an older age. Fertility rates are not
as low as they appear to be."