Malthusian Idea

The Malthusian idea is a central concept in discussions about the global future of the world's population. Although thinkers in many cultures have, since antiquity, concerned themselves with questions of population dynamics and their effects on various aspects of society and governance, the Reverend Thomas Robert Malthus (1766–1843) is generally credited with bringing new levels of rigor and lasting insights to the subject, casting him as a founding figure in the modern disciplines of demography, sociology, and evolutionary biology, as well as being the recipient of the first academic appointment in political economy.

The Malthusian idea—usually summarized as saying that human population has the capacity to grow geometrically (1, 2, 4, 8, 16, 32, 64, 128, 256, etc.) while the means of subsistence grows only arithmetically (1, 2, 3, 4, 5, 6, 7, 8, 9, etc.)—had an immediate impact on its publication in 1798 in An Essay on the Principle of Population, as It Affects the Future Improvement of Society. This was followed by a much expanded and less polemical edition in 1803 and further editions in 1807, 1817, and 1826. The lasting significance of the Malthusian idea is attested to by its continued salience in the present era's debates over various aspects of globalization, especially those related to population dynamics, the sources of and solutions to poverty, economic development strategies, and environmental sustainability.

Indeed, some present-day observers have seen fit to divide divergent positions in these debates into polar opposites designated as Malthusians (or neo-Malthusians) versus Cornucopians, exemplified by such figures as Paul Ehrlich and Julian Simon, respectively. Nor should it be surprising that present-day views are arranged around pessimistic and optimistic poles, as Malthus's original work was designed as a polemic against [Page 1101]the then-fashionable utopian works of the Marquis de Condorcet and William Godwin.

The first basic component of the Malthusian idea, regarding the geometric growth of human population, has fared better historically than the second, regarding the merely arithmetic growth of the means of subsistence. Malthus explicitly recognized that a literally geometric expansion of human population would never occur, because of a variety of what he termed positive and preventive checks (all of which involved major suffering and/or deprivation). Instead, he postulated a potential doubling every 25 years. In global terms, even that more modest growth rate turns out to have been overstated. Total world population was an estimated 1 billion in Malthus's day (1804) and did not double until 1927, a period of 123 years. After that, it doubled again in 47 years, reaching 4 billion in 1974, and is estimated to double again, to 8 billion, by 2025, an interval of 51 years. It is then projected to peak at around 9.2 billion in the 2050s.

Even though this increase is by no means geometric and is considerably less than that projected by Malthus, it is still by far the most rapid increase in history and worthy of attention, if not alarm. However, most observers agree that neo-Malthusian Paul Ehrlich went overboard with his 1968 predictions that hundreds of millions would starve to death in the 1970s and 1980s and that India could never feed as many as 700 million people (its current population stands at 1.15 billion).

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