Population

Over the past two centuries many theorists have tried to explain why populations change, which patterns they follow, and what can be expected In the future. The theories of four prominent people are examined here. Although two of these theorists, Thomas Malthus and Karl Marx, belong to the last century, their remarks are both interesting and important in providing historical perspective. The third, William Catton, provides controversial analyses of our current population dilemma. The fourth, Donald Bogue's theory of demographic regulation, is a fairly recent assertion (1969) that societies facing the probability of overpopulation inevitably find a natural means of regulating their own increase.

The Malthusian Case

In 1798 an English clergyman, Thomas Robert Malthus (1766-1834), wrote a book entitled An Essay on the Principle of Population. It is generally considered to be the first book written on the subject of population. Its importance is demonstrated by the fact that almost 200 years later it is still in print.

Malthus was writing about the problem of population growth, but his concern was primarily with England. He was, of course, unaware of the events of the demographic transition. However, his theory is still widely known today. To understand his main ideas, a few paragraphs from his work are included here. While reading these excerpts keep in mind two questions: What was his explanation for population growth? Do his Ideas have any relevance today?

Malthus's objective was "to investigate the causes that have hitherto impeded the progress of mankind towards happiness.... The cause to which I allude is the constant tendency in all animated life to increase beyond the nourishment prepared for it." Malthus wrote his essay to try to explain why so many people in England were living in poverty. He believed the main reason was because the population was growing faster than the food supply (which he refers to as subsistence): "In plants and irrational animals, the view of the subject is simple. They are all impelled by a powerful instinct to the increase of their species; and this instinct is interrupted by no doubts about providing for their offspring. Wherever therefore there is liberty, the power of increase is exerted, and the superabundant effects are repressed afterwards by want of room and nourishment.

"The effects of this check on man are more complicated. Impelled to the Increase of his species by an equally powerful Instinct, reason interrupts his career, and asks him whether he may not bring beings into the world for whom he cannot provide the means of support. If he attend to this natural suggestion, the restriction too frequently produces vice IMaIthus uses this word to describe all of those measures that would be considered birth control]. If he hear it not, the human race will be constantly endeavouring to Increase beyond the means of subsistence. But as, by that law of our nature which makes food necessary to the life of man, population can never actually increase beyond the lowest nourishment capable of supporting It, a strong check on population, from the difficulty of acquiring food, must be constantly in operation. This difficulty must fall somewhere, and must necessarily be severely felt in some or other of the various forms of misery, or the fear of misery, by a large portion of mankind. [Malthus uses the word "misery" to refer to the conditions produced by disease, starvation, and war.]" Rales of Increase. Malthus suggests that population left unchecked goes on doubling, or increases geometrically (e.g., 1,2,4,8...), while subsistence (food) only increases arithmetically (e.g., 1,2,3,4...). He illustrates this in the following example. "The necessary effects of these two rates of increase, when brought together, will be very striking. Let us call the population of this island Britain eleven millions; and suppose the present produce (subsistence) equal to the easy support of such a number. In the first twenty-five years [Malthus assumed a doubling time of twenty-five years which was a much higher rate of growth than actually existed in Britain at the beginning of the nineteenth century] the population would be twenty-two millions, and the food being also doubled, the means of subsistence would be equal to this increase. In the next twenty-five years, the population would be forty-four millions and the means of subsistence only equal to the support of thirty-three millions. In the next period the population would be eighty-eight millions, and the means of subsistence just equal to the support of half that number. And, at the conclusion of the first century [assuming this doubling time of twenty-five years], the population would be a hundred and seventy-six millions, and the means of subsistence only equal to the support of fifty-five millions, leaving a population of a hundred and twenty-one millions totally unprovided for....

"In this supposition no limits whatever are placed to the produce of the earth. It may increase forever and be greater than any assignable quantity; yet still the power of population being in every period so much superior, the increase of the human species can only be kept down to the level of the means of subsistence by the constant operation of the strong law of necessity, acting as a check upon the greater power." The Checks to Growth. Malthus then examines "the general checks to population" that keep the population down to the level of the subsistence being provided.

The first of these are the preventive checks. These were based on the assumption that couples could recognize the size of family they were able to support and would plan accordingly. Among these checks were "moral restraint" (delay of marriage) and "vice" (measures of birth control). In reality, however, Malthus did not believe the first would work, and, like most of his contemporaries, believed that the second was morally wrong, causing in his words, a lowering of the dignity of human nature.

The other checks he called the positive checks, which were: "extremely various and include every cause, whether arising from vice or misery, which in any degree contributes to shorten the natural duration of human life. Under this head, therefore, may be enumerated all unwholesome occupations, severe labour and exposure to the seasons, extreme poverty, bad nursing of children, great towns, excesses of all kinds, the whole train of common diseases and epidemics, wars, plague, and famine."

Malthus's viewpoint aroused much criticism and has' been a source of controversy ever since. Since he did not believe that moral restraint would work and could not accept birth control, there wasn't much left except "misery." In his view, famine, disease, and war were the ultimate and irrevocable determinants of pop tion growth. Technological change could not raise production levels above population growth rates, and population growth would not be limited by fewer births, only by more deaths. He believed that Britain and other countries would be afflicted with increasing hunger and other forms of misery as the population continued to rise.

It is not difficult to see why Malthus was known as the "gloomy parson"; his views were clearly pessimistic and as such ran contrary to the generally optimistic view of his time that science and reason were in the' process of producing a better world for all. According to Malthus, people were caught in a hopeless trap, on the losing side in the struggle between growth in the numbers of people and the availability of food. In the age of Napoleon, his popularity in Britain was said to be less than that of the French emperor whose goal was the destruction of the country.

Malthus Today.

As a result, the conflict that Malthus predicted between the increase in population and the means of subsistence was averted. The Industrial Revolution, contrary to what Malthus believed, did bring about geometrical increases in subsistence which, combined with other developments. led to the demographic transition and a fivefold increase in world population since Malthus wrote his essay.