An Essay on the Principle of Population by Thomas Robert Malthus

First published: 1798, rev. eds. 1803, 1806, 1807, 1817, 1826

Type of Philosophy: Ethics, social philosophy

Context

Thomas Robert Malthus lived through the last third of the Enlightenment and witnessed the stirring events of the French Revolution and the subsequent convulsions of the Napoleonic era. The progression of the French Revolution from modest, Enlightenment-based liberalism through radicalism to a violent reaction against the early liberalism no doubt affected Malthus, who came from a liberal family. The global conflicts of the Napoleonic era also led to the centralization of power in national governments, which meant that statistical information was collected on a much wider scale than before. The national censuses instituted in 1790 in the United States and in 1801 in Britain provided the numerical data on which mathematical models of society could be based. Malthus also benefited from the contemporary developments in mathematics, which in turn drew on new understanding in the field of astronomy, leading to the creation of mathematical models of the universe. Malthus was one of the first of a long line of thinkers of the nineteenth century to attempt to apply mathematical models to society.

The origin of An Essay on the Principle of Population is said to have been an argument Malthus had with his father over the view advanced by reforming Englishman William Godwin and the Marquis de Condorcet, among others, on the perfectibility of humankind. Malthus argued that the pressure of population on the means of subsistence ensures that the bulk of the population will live at a low level. If by chance the lot of an ordinary worker improved, he would immediately rush into marriage and bring into being numerous children whom he would be unable to support. He would then sink back into a marginal existence.

Malthus, reflecting his status as a clergyman, laid stress on the obligation that God imposed on every man to support his children. He further accepted the biblical urging to every person to multiply and be fruitful. Combining these two mandates of God meant that the prudent man would postpone marriage until he could clearly see how he could support his children. However, the poor had no sense of prudence; they married early and had abundant children, whom they were then unable to support, forcing them to rely on society through the “poor laws,” the welfare system of the England of that time. The recent sharp increase in the “poor rates,” the taxes levied on property owners specifically for the support of the poor, was, to Malthus, a clear demonstration of the operation of the principle of population.

Population and the Food Supply

In the first edition of An Essay on the Principle of Population, Malthus devotes many pages to refuting the ideas of Godwin and other Enlightenment thinkers on the perfectibility of humankind. In later editions, however, he eliminated these sections and replaced them with an exhaustive survey of the world’s population, region by region, based on population data such as that collected in the 1801 and subsequent censuses in Britain. He also drew on information he had collected on two trips to Europe, in 1799 and 1802. He frequently drew comparisons with China, which he felt clearly exemplified the operation of the principle of population. However, a major benchmark was the data on population in the United States, enumerated in the 1790 and subsequent censuses. The average growth of the population of the United States indicated that, where no shortage of farmland existed, the population would double in twenty-five years; indeed, in some frontier communities, as quickly as every fifteen years. The first census in Britain, in 1801, caused him to revise some of the figures quoted in the first edition of An Essay on the Principle of Population, in which he had estimated the population of Great Britain as seven million. The census of 1801 revealed that, on the contrary, the British already numbered eleven million.

Using some of the new statistical data, Malthus demonstrates how the mathematical model underlying the principle of population would operate. In the first twenty-five years, the population and the food supply could very well increase at the same rate, from one to two; but in the second twenty-five years, the population would increase from two to four, whereas it was inherently unlikely that the food supply would increase by more than the amount it had increased in the preceding twenty-five years, that is, from two to three. In the third quarter-century, the discrepancy would be marked, as the population would now be eight times its size at the outset, and the food supply would be only four times as large. Thus, in as little as seventy-five years, half the population would be without food.

There has been substantial debate among economists as to whether Malthus had a concept of diminishing returns. He certainly did not use this concept to characterize his assertion that the food supply could not be increased at the same rate as population, in part because he understood the variable productivity of land. He accepted, as did his contemporary and ideological opponent, David Ricardo, that increasing agricultural output meant bringing into production marginal lands, that the best and most productive land would be the first that would be cultivated. He argued, based on his own observations of rural England, that doubling the agricultural labor force would not double the agricultural output because the additional labor would be put to work on “marginal” land. The more marginal the land, the less output could be expected from it, even if the labor input was equivalent to that on the best land.

Malthus grappled with, but never fully integrated into his thinking, the effect of emigration on the population. He acknowledged that the ability particularly of Englishmen to emigrate to the New World, where the supply of farmland was plentiful, had helped to postpone the inherent conflict between population and food supply within England, but he maintained that emigration did not fundamentally alter the operation of his principle. Also, the growth of industrial jobs did not undo the principle, for the fundamental constraint was the food supply.

Malthus maintained that a nation’s ability to feed its own population was a necessary part of the sovereignty of any nation. Any country that became permanently dependent on foreign food supplies would lose its ability to act independently. In this observation, Malthus was reflecting the condition of England in his own times. An exporter of grain in the eighteenth century, except for a couple of years affected by adverse weather conditions, England was becoming an importer of grain. Malthus felt this conversion contained alarming prospects for England’s future ability to conduct an independent foreign policy.

Implications for Policy

In attempting to make policy recommendations on the basis of his principle, Malthus first recommended abolishing the existing poor laws, under which indigent persons could receive financial support from public funds. At a certain date in the future, such support should end, and the indigent be told to look for help from private charities. Malthus’s ideas played an important part in the intensive debate then occurring in England as to the appropriate welfare policy for the nation. His ideas clearly contributed to the attitudes of the politicians who reformed England’s welfare system in the “New” Poor Law of 1834.

Malthus strongly favored a system of state-supported public education (which did not then exist), holding that educated men, especially if taught about the principle of population, would be more likely to postpone marriage until they could support their children. These ideas are reflected in many late twentieth century views on population that stress the education of women as central to solving population pressures in developing countries.

Malthus had a profound impact on social and political theorizing. His ideas have been used to support restrictions on immigration and to support birth control, although Malthus himself opposed artificial means of limiting births. Some of the startling improvements in agricultural output in the late twentieth century have been hailed as invalidating Malthus’s principle of population, as has the striking slowdown in population growth in industrialized economies. On the other hand, the rapid population growth in underdeveloped countries has been seen as an affirmation of the principle of population, especially as indigenous food supplies prove increasingly inadequate. The jury is still out on the principle of population.

Malthus’s use of mathematical models influenced nearly all twentieth century social theorizing. The collection of statistics, such as the censuses that Malthus quoted and manipulated in the second and subsequent editions of An Essay on the Principle of Population, has been expanded and refined enormously since Malthus’s time. Statistics detailing the demographics of modern society have been collected in huge computer databases to make it easier to analyze the data and create predictive mathematical models. Nearly all contemporary social analyses use statistical material in support of their theses.

Economists debate whether Malthus used inductive or deductive reasoning. His assertion of the principle of population and his subsequent accounts of the conditions in various countries in the light of it suggest deductive reasoning; but his method of arriving at the principle, on the basis of observations of the world around him, especially rural England, is a classic case of inductive reasoning.

Principal Ideas Advanced

•Population increases geometrically; food increases arithmetically.

•Food is an essential of human life; “passion between the sexes” is a fundamental human quality and likely to remain so.

•The experience of the United States shows that, when not subject to the limitations of the supply of farmland, population will double in twenty-five years.

•Population and food tend to be in an uneasy balance, at the subsistence level.

•There are two kinds of checks on population growth: the preventive, in which the age of marriage is deferred until the breadwinner is able to support a family, and the positive, in which children die young for lack of adequate sustenance.

Bibliography

Appleman, Philip, ed. Thomas Robert Malthus: An Essay on the Principle of Population, Text Sources, and Background Criticism. New York: W. W. Norton, 1976. Contains selections from the writings of the Marquis de Condorcet and William Godwin and the first and second editions of An Essay on the Principle of Population, as well as responses, positive and negative, from critics of the nineteenth and twentieth centuries.

Dupaquier, Jacques, et al., eds. Malthus, Past and Present. New York: Academic Press, 1983. A selection of papers presented in 1980 at the International Conference on Historical Demography. Contains useful information on the influences on Malthus, the conditions of his time, and the neo-Malthusian movement.

Hollander, Samuel. The Economics of Thomas Robert Malthus. Toronto: University of Toronto Press, 1997. This lengthy study is the definitive view of Malthus’s economic analysis.

James, Patricia. Population Malthus: His Life and Times. London: Routledge and Kegan Paul, 1979. An excellent biography.

Peterson, William. Malthus. Cambridge, Mass.: Harvard University Press, 1979. An intellectual biography that sets the work of Malthus in the context of early nineteenth century thought.

Turner, Michael, ed. Malthus and His Time. London: Macmillan, 1986. Further selections, somewhat more technical, from the 1980 international conference on historical demography.

Winch, Donald. Malthus. New York: Oxford University Press, 1987. Succinctly reviews Malthus’s economic ideas in just more than one hundred pages.

Wood, John Cunningham, ed. Thomas Robert Malthus: Critical Assessments. 4 vols. London: Croom Helm, 1986. The one hundred reprinted articles and excerpts give a sweeping overview of reactions to Malthus’s work.