The survival of a population depends ultimately on a sustainable supply of essential resources, particularly fresh water and food. If these are not available in sufficient quantities to sustain the people living in a nation or region, the population has exceeded the carrying capacity of that nation or region. Both populations and supplies of fresh water and food are dynamic, not static. Usually, in most nations, there is a positive balance—the nation or region either has, or can afford to import, a sufficient supply of fresh water and food to enable all currently living to survive, with enough left over to allow for natural population increase. However, sometimes the rate of increase of a nation's or region's population is greater than the capacity of the local or regional ecosystems to produce the food that is necessary for all to survive, and there are no financial resources to import these necessities for survival. Moreover, natural or manmade disasters can tip the balance by disrupting food supplies.
A population that has exceeded the national or regional carrying capacity is said to be caught in a demographic trap. Such a population must migrate out of the region, or it will starve unless it receives food aid. Another possible consequence may be violent armed conflict if the demographically trapped population encroaches on the territory of neighboring nations who regard them as unwelcome intruders.
The concept of the demographic trap first appeared in the annual report of the Worldwatch Institute in 1987. It was discussed at a major World Health Organization (WHO) conference in 1988, and has been much discussed since then; a major proponent of the concept has been the English public health specialist Maurice King. It is, however, a controversial concept. Many public health scientists and policymakers see the demographic trap as an inevitable fulfillment of the calculations first published by Thomas Malthus in 1798. Malthus proposed that while populations expand exponentially, food supplies grow only in arithmetical progression, so eventually populations outstrip food supplies, with famine the inevitable result. Empirical observations appear to have confirmed the truth of this in some regions afflicted with famine in Africa and Asia during the latter part of the twentieth century.
Other authorities, notably the Nobel Prize–winning economist Amartya Sen, dispute this concept, asserting that when famines occur, food is in fact available. Those who need it, however, cannot afford it or are denied access to the food supply for logistical or political reasons. The debate over the concept of the demographic trap has involved epidemiologists, economists, political scientists, public-policy analysts, family planning experts, agronomists, and others—including representatives of the religious right wing and advocates of enhanced rights and freedoms for women. The debate has sometimes become polarized along ideological fault lines, with those in favor of population control policies embracing the concept, and those opposed to such policies adjusting to it. Famine and overpopulation are harsh realities, so it is regrettable that ideologies and emotions can cloud the important issues involved.
John M. Last
(see also: Carrying Capacity; Famine; Malthus, Thomas Robert; Population Growth; Population Policies; Refugee Communities; Sustainable Health )
King, M., and Elliott, C. (1993). "Legitimate Double-Think." Lancet 341:669–672.
Sen, A. (1989). On Ethics and Economics. Oxford, UK: Blackwell.
—— (2000). Development as Freedom. New York: Doubleday.
Worldwatch Institute (1987). State of the World 1987. Washington, DC: Worldwatch Institute.
World Health Organization (1988). From Alma-Ata to the Year 2000: Reflections at the Midpoint. Geneva: Author.
"Demographic Trap." Encyclopedia of Public Health. . Encyclopedia.com. (August 17, 2018). http://www.encyclopedia.com/education/encyclopedias-almanacs-transcripts-and-maps/demographic-trap
"Demographic Trap." Encyclopedia of Public Health. . Retrieved August 17, 2018 from Encyclopedia.com: http://www.encyclopedia.com/education/encyclopedias-almanacs-transcripts-and-maps/demographic-trap