Demography
Trends
Halting Population Growth
by Clifton Coles
Low fertility rates will halt population growth worldwide.
Demographers now generally agree
that the twenty-first century is likely to see the end of world population growth. The
cause: significant fertility declines around the world that are unlikely to stop at the
replacement level of around 2.1 children per woman.
But before growth levels off and possibly decreases, at least 2 bilion
will be added to total world population. Women around the world now have fertility levels
well below those needed to reproduce their populations, say Wolfgang Lutz, Warren C.
Sanderson, and Sergei Scherbov of the International Institute for Applied Systems
Analysis. "Spain and Italy used to be relatively high fertility countries," they
write in The End of World Population Growth in the 21st Century. "Today,
fertility levels there are so low that, on average, 100 women of reproductive age will
produce only 65 daughters to follow them as potential mothers in the next
generation."
According to the demographic transition theory, as living
standards rise and health conditions improve, mortality rates should decline, followed by
a decline in fertility rates sometime later. In more-developed countries, the mortality
rate generally began its decline in the late 1700s, while the fertility rate's decline
began up to 100 years later.
Different societies experience the demographic transition at different
rates; in many developing countries, it began in the latter half of the twentieth century.
Furthermore, the decline in the mortality rate in developing nations has occurred very
rapidly, from an average of 40.9 years at the end of World War II to 63 years in 2000. The
IIASA researchers expect that declines in fertility will follow; zero population growth or
even population decline will occur by the end of the twenty-first century, they predict.
Of the world's developing nations, China is furthest along in its
demographic transition. Fertility rates there have declined from 4.2 births per woman in
1974 to 1.85 births in 1995. Government family-planning programs have strongly influenced
these numbers, but education is an important determinant in fertility reduction. Education
influences the age at which women marry, for instance; as women stay in school longer and
as their employment opportunities widen with education, they delay giving birth and
rearing families.
A number of important developments suggest that fertility in China will
remain below replacement levels over the long term. According to the IIASA analysts,
fertility declines have gained momentum and are less dependent on government policies than
once thought. Survey information about desired family size shows strong declines among
younger generations, and there are indications that couples overwhelmingly elect to have
one child even when the one-child policy is relaxed.
China will also experience a considerable aging in its population. IIASA
predicts that the proportion of the population 60 years old and older will likely reach
around 40% during the second half of the century.
Although the authors expect most countries to complete their demographic
transition during the twenty-first century, "low human capital, weak institutions,
political instability, and high economic and environmental vulnerability pose significant
limits to their prospects for social and economic development." As the century
proceeds, they stress the necessity for focusing on the quality of life rather than the
number of people on the planet. They see education--especially for young women--as
essential to improving health, eradicating poverty, and enhancing productivity in a wide
variety of activities by the end the century.
Source: The End of World Population Growth in the 21st Century: New
Challenges for Human Capital Formation and Sustainable Development edited by Wolfgang
Lutz, Warren C. Sanderson, and Sergei Scherbov. Earthscan, www.earthscan.co.uk. 2004. 341
pages. Paperback. Order:
For more information on the International Institute for Applied Systems Analysis, visit www.iiasa.ac.at.
