Return to [previous page]
John Bongaarts
on Mon, January 7, 2013 at 06.54 pm
Population Dynamics

Why rapid population growth is a problem



John Bongaarts:

Population growth remains rapid in many poor countries. For example, the population of West Africa is expanding at an annual rate of 2.6 % and is expected to more than quadruple in size by the end of the century. The projected addition of one billion people to the region’s current population of 320 million is an obstacle to development and makes it difficult to be optimistic about the future of this and other regions with similar demographic and socio-economic conditions. There are several reasons for concern:

-Environmental degradation: Global environmental problems (e.g. climate change, decreasing biodiversity) receive much media and scientific attention in the West, but are not a high priority for policy makers in poor countries, except where substantial populations live in low lying coastal areas (e.g. Bangladesh). Instead, most developing countries have critical local environmental problems that require urgent attention, including shortages of fresh water and arable land, and water, air and soil pollution. Environmental stresses have been building up over time and are likely to become much more severe as populations and economies expand further.

-Economic stagnation: In poor societies population sizes often double in two or three decades. As a result, industries, housing, schools, health clinics, and infrastructure must be built at least at the same rate in order for standards of living not to deteriorate. Many communities are unable to keep up, as is evident from high unemployment rates, explosive growth of slum populations, overcrowded schools and health facilities and dilapidated public infrastructure (i.e. roads, bridges, sewage systems, piped water, electric power, etc)

In addition, rapidly growing populations have young age structures. The resulting low ratio of workers to dependents depresses standards of living and makes it more difficult to invest in the physical and human capital needed for expanding economies. The size of the formal labour force is also limited by the need for women to remain at home to take care of large families.

-Maternal mortality: High birth rates imply frequent childbearing throughout the potential reproductive years. Each pregnancy is associated with a risk of death, and this risk rises with age of the mother and the order of the pregnancy. In the least developed countries the life-time risk of dying from pregnancy related causes is near 5% and many more women suffer related health problems or disabilities.

-Political unrest: Half the population of the least developed world is under age 20. Unemployment is widespread because economies are unable to provide jobs for the rapidly growing number of young people seeking to enter the labour force. Vigorous competition for limited numbers of jobs leads to low wages which in turn contributes to poverty. The presence of large numbers of unemployed and frustrated males likely contributes to socio-economic tensions, high crime rates and political instability.

Of course, population growth is not the only or even the main cause of poverty in the developing world. Nevertheless population growth has pervasive adverse effects on societies and hinders development efforts. Poor countries would be better off with lower population growth rates.


David Lam:

I agree with John Bongaarts that rapid population growth continues to pose serious challenges for many poor countries, especially in Africa.  John provides a clear statement of several of these important challenges.   John argues that these countries’ rapid population growth makes it difficult to be optimistic about their future.  While I also worry about the future of the world’s poorest countries, their demographic conditions alone should not be viewed as preventing economic development.  To see why, we need to put these conditions into a historical perspective.

The 2.6% annual population growth rate that John reports for West Africa is indeed very high and a cause for concern.  It is important to keep in mind, however, that many middle income countries experienced similar growth rates.  Brazil and Thailand, for example, had annual population growth rates of 3% per year in the 1950s and at least 2.6% per year in the 1960s.  Both had over half their population under the age of 20 throughout the 1950s, 60s, and 70s, similar to the percentage John reports for the poorest countries today.  In spite of these demographic challenges, both countries have had strong economic performance.  Brazil’s per capita income in 2011 was about 3.3 times its 1960 level; Thailand’s per capita income in 2011 was about 8.4 times its 1960 level.

Brazil and Thailand have both had large declines in fertility, a factor that has contributed to their economic success. But both had rapid growth of per capita income during the 1960s and 70s, a time when their populations were growing as fast as West Africa is growing today.  And while Brazil and Thailand have been particularly successful, they are broadly representative of Latin America and Southeast Asia more generally.

There are two lessons here.  First, the demographic challenges we see in the poorest countries today are similar to those experienced by other developing countries in the last 50 years.  Second, it is by no means impossible to have rapid economic growth at the same time as rapid population growth.  Africa’s high population growth may be more a symptom than a cause of poor economic performance, a theme I will return to in future entries.


bongaarts, lam
Population Growth, Environmental Degradation, Water, Health, Growth
Africa, Bangladesh, Brazil, Thailand, Asia
Randolph Femmer from
Fri, January 11, 2013 at 03.44 pm
Responding to the above article by John Bongaarts: First, we believe that this discussion should include a graph of the worldwide population growth of our species which is a J-CURVE ( image is accessible at and note that humankind is, on a global scale, skyrocketing upward along the y-axis of our curve almost exactly like the fission progressions that flattened Hiroshima and Nagasaki at the end of World War II. Although it has become fashionable in some literature in recent decades to depict or envision worldwide population growth as an "s-curve," it is important to note that the authors of such "s-curve" graphs are only able to generate such a shape by: (1) conveniently ignoring and omitting the first 9,900 years of civilization from their graphs, so that their graphs begin sometime in, for instance, the 1970s or 1980s, and then (2) graphing the data from the 1970s or 1980s up to the present, and then (3) projecting their graphs for another five or six decades into the future on the basis of their own guesses, hopes, assurances, and suppositions in order to portray humankind's demographic future as some happy equilibrium of sustainability and environmental bliss. (If a J-curve of this shape were to appear on the monitor screens of a nuclear power plant, it would send the plant's engineers scrambling for the exits.)

As a second observation concerning Dr. Bongaart's post, for some reason there appears to be no mention (nor contemplation of?) of classical real-world population terms such as carrying capacity, or limits, or thresholds, or tipping-points, or overshoot, or the OTHER type of real-world population outcomes known as "Climb-and-collapse." The careful reader must wonder why not? Why are such crucial, classical, and quintessential real-world life-and-death realities missing and not even referenced or mentioned when we are looking at (1) a J-curve;
(2) the greatest single risk in the entire history of our species, and (3) what appear to be calamitous damages to and eradications of the only biospheric life-support machinery so far known to exist anywhere in the universe?
Randolph Femmer from
Fri, January 11, 2013 at 03.44 pm
Dear David: In your reply to Dr. Bongaarts, you say " is by no means impossible to have rapid economic growth at the same time as rapid population growth." Don't you think that residents, young people, and leaders in the world's least-developed and highest-fertility nations would have a BETTER CHANCE of raising standards of living if they were working with stable populations? Hasn't the formula that your comment seems to suggest (as quoted above) already been tried across vast regions for many decades now? (List the nations with the world's highest-fertility rates and most explosively-growing populations, together with a listing of failed states, poverty, hunger, unemployment, instability, and inadequate access to education and health care and notice how well the two lists match up.) These nations have already tried the explosive population growth strategy now for two and three decades and more, and despite years and years of foreign aid efforts, assistance, and tons of money, that strategy has failed.

To quote the familiar saying, if one is trying to escape from a hole, the first rule is to stop digging. In other words, over the past thirty years, as the citizens and leaders in the world's poorest countries can attest, the high-population-growth way forward that you seem to suggest has already been tried and that policy hasn't worked. And lastly, it seems worth noting that one of the countries with the LOWEST fertility rates in the entire world over the past three decades at the same time was able to achieve some of the most dramatic advances in economic growth and in standards of living.
Comment settings
Select your preferred way to display the comments and click "Save settings" to activate your changes.
Please or Sign Up to post a comment.