The Tragedy of the Commons

I'm glad we read this. I encountered it earlier in an environmental science class, and always wanted to come back to it.

Hardin ties the idea of a shared pasture with individual herdsmen vying for ever-increasing shares of the resource to overpopulation, and argues that population problem "has no technical solution, but requires a fundamental extension in morality." His scientific paper was notable for its discussion of morality (Wikipedia, 2006).

Last year I wrote a paper for an international relations class examining the population problem and have posted some excerpts here. Current projections indicate human population may top out at about 9 billion by mid-century and then begin declining (PRB, 2004).

"Historically, human population has been remarkably stable, with high birth and death rates ranging from 30 to 50 per thousand per year (PRB, 2004). High birth rates were necessary to maintain population numbers; this pattern held true regardless of culture or ethnicity. For example, in England in the 17th century, 60% of children did not survive to the age of five, and only 30% survived to age 15—old enough to procreate (PRB, 2004). For most of human history, the combined high birth and death rate resulted in very slow population growth.

The first well-known attempt to describe human population trends was by Thomas Malthus. At the end of the 18th century, he published a book, Essay on the Principle of Population, which postulated that “war, famine and disease” were inevitable to counteract the tendency of population to grow geometrically while food production could only grow arithmetically. This theory gained credence because it was mathematically formulated, at a time when the rational approach to intellectual inquiry was first becoming fashionable. He believed that the poor in particular should exercise “self-restraint” to keep from increasing in number (Montgomery, no date). His theory of population growth being tied to war, famine, and disease became known as the Malthusian trap (Peterson, 1999).

Beginning in the 1920s, demographic transition theory took root as a way to explain population trends. This theory posits that industrializing nations pass through four stages: stage one, with high birth and death rates; stage two, with high birth rates and falling death rates (due mainly to decreasing death rates of children 0-5 as sanitation and medical care improve); stage three, in which birth rates fall since children become an economic liability instead of an asset, and access to contraception improves; and stage four, characterized by the low birth and death rates seen in industrialized countries (Montgomery, no date). Large increases in population are seen in stage two since birth rates far exceed death rates at this juncture. This is the state that many developing nations are currently in, which explains the continuing rapid increase in world population even though birth rates are stabilizing or even falling.

Interestingly, it has been noted that developing nations appear to be going through the demographic transition much more rapidly than the developed nations did. A comparison of Mexico’s transition to that of Sweden’s in the 18th century shows that while Sweden’s fertility and mortality declined fairly slowly over a period of 150 years, Mexico experienced a rapid increase in population when the death rate fell quickly, which led to the government policies which encouraged contraception and education (PRB, 2004).

Mexico’s birthrate fell from 7 children per woman in 1965 to 2.5 in 1999. The government encouraged this trend with a 25-year ad campaign extolling that “small families live better.” Traditionally, Mexicans held a belief that one of the reasons they lost the southwest to the U.S. was that the sparse population impeded their ability to defend the territory, and as a result of this loss, population growth was encouraged. The government’s 1974 about-face on population growth expanded women’s access to contraception and dramatically affected the birthrate (Dillon, 1999). Likewise, China’s well-known “one-couple, one-child” policy has dramatically dropped the birthrate, although not without controversy or unintended consequences—such as the gender imbalance brought on by the cultural preference for sons and consequent abortion of female fetuses (PRB, 2004). Nonetheless, these examples show that government policies can have dramatic effects on population numbers.

A more recent concern is what the implications of declining national populations are. Whole new issues arise in nations which have a fertility rate below the replacement level: low birth and death rates imply an aging population, with a set of problems the world has not seen before (Longman, 2005). The capitalist model assumes continued economic growth; what happens to this growth if fewer people need goods and services? Who will care for an aging population, and how will government entitlement programs deal with a declining worker-to-retiree ratio? Governments are just beginning to address the far-ranging implications of these trends, which are evident in countries such as Japan, Russia, and Germany.

Post-industrial societies have factors which work in favor of very low fertility. Contraceptives, career choices, the economic drain of childrearing, “biological clock” factors, lack of a desirable partner, unstable employment, and high housing prices can all cause women to reconsider how many children they have, if they have them at all. Even in developing countries, rising education levels cause women to delay marriage, use more contraception, and have fewer children (PRB, 2004).

There are positive benefits, called the “demographic dividend” of declining populations. Some experts believe that having fewer children frees resources for investment, labor, and other pursuits (Longman, 2005). Certainly, the environment benefits when fewer humans compete for resources."

While it could be argued that Hardin is correct that a "moral" solution (we could have quite a discussion over the morality of China's policy, in particular) rather than a technical one is needed to solve the problem of overpopulation, he did not foresee the benefits, and therefore the motivation, to individual women of having fewer children (better educational and economic opportunity), nor did he predict that later-industrializing countries would progress more rapidly through the cycles.

I'll have to further ponder the relationship between tragedy of the commons to today's technological environment, but I thought brief review of the human population problem might provide an interesting background.


Dillon, S. (June 8, 1999). Small Families Bring Big Change in Mexico. The New York Times. Retrieved 8/9/05 from the World Wide Web. http://www.uwmc.uwc.edu/geography/Demotrans/mexpop.htm

Longman, P. (2005). The Global Baby Bust. Annual Editions: Developing World. Dubuque, IA: McGraw-Hill/Dushkin.

Montgomery, K. (no date). Demographic Transition. University of Wisconsin, Department of Geography and Geology. Retrieved 8/9/05 from the World Wide Web. http://www.uwmc.uwc.edu/geography/Demotrans/demtran.htm

Montgomery, K. (no date). Thomas Malthus. University of Wisconsin, Department of Geography and Geology. Retrieved 8/9/05 from the World Wide Web. http://www.uwmc.uwc.edu/geography/Demotrans/malbox.htm

Population Bulletin (March 2004). Population Reference Bureau. Retrieved 8/9/05 from the World Wide Web. http://www.prb.org/Template.cfm?Section=Population_Bulletin2&template=/ContentManagement/ContentDisplay.cfm&ContentID=12488

Projected Population of the United States, 2000 to 2050. (2004). U.S. Census Bureau. Retrieved 8/12/05 from the World Wide Web.
http://www.census.gov/ipc/www/usinterimproj/natprojtab01a.pdf

World population growth rate continues to plummet. (May 2, 2005). Mongabay.com http://news.mongabay.com/2005/0502

World Population Prospects: The 2004 Revision and World Urbanization Prospects. (May 2, 2005). Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat. Retrieved 8/12/05 from the World Wide Web. http://esa.un.org/unpp
Tragedy of the Commons. (October 2006). Wikipedia. Retrieved 11/13/06 from the World Wide Web. http://en.wikipedia.org/wiki/Tragedy_of_the_commons