1. Explain and evaluate critically Malthus's population theory.
In 1798 Thomas Robert Malthus, a British clergyman and professor, wrote an essay showing the way to modern demography. In 1824 he wrote a shorter final version, the article on population for that year's Encyclopedia Britannica. Malthus has been criticized for his lack of scientific foresight-he did not foresee modern advances leading to increased life expectancy, food production and birth control. He has been criticized for his politics-he thought welfare immorally increased population and hunger. He has been criticized for pessimism-the adjective Malthusian is associated with a gloomy outlook for humanity. But he showed the way for the study of human population.
People. To learn how fast people might reproduce, Malthus examined the United States census. Conveniently, that count was required each decade, starting in 1790, by the Constitution of the former British colonies. Land was so fertile and uncrowded that food production seemed not to limit population growth. Immigration counts were available to subtract from natural rates of population growth, thus revealing net reproductive growth. Malthus observed that under such ideal conditions, during each 25 years the human population tends to double. So if world population is represented by 1, then after each 25 years it would be 2, 4, 8, 16, 32 and so on, provided there were no limits on such «;natural»; rates of population increase.
Food. To learn how fast people might produce food, Malthus examined agriculture in several countries, and made a rough estimate: all food produced could increase each 25 years by at most the prior 25 years' increase. So if food production is represented by 1, then after each 25 years it would be 2, 3, 4, 5, 6, and so on. In other words, food could only increase arithmetically, whereas the population if otherwise left unfettered would tend to increase geometrically.
Checks on Population. Malthus concluded that, since food is necessary to human life, world population will necessarily grow slower than its natural trend. Malthus postulated two types of checks on human population growth---positive and negative. Positive checks are increases in the death rate as a result of wars, famines, disease, and similar disasters. A negative check is the lowering of the birth rate, which is best accomplished by the postponement of marriage. However, given his moral code, Malthus was forced to conclude that the postponement of marriage could only result in vice, misery, and degradation of character, because premarital sexual relations would occur.
In other words, his core conclusion was that unless people stopped multiplying, there would not be enough food, regardless of how hard they worked to produce it.
Maltus's fearful prediction has not yet been fulfilled world wide, although it is a reasonable description so some countries, past and present. Although the world's population has continued to increase at a phenomenal rate, the overall food supply generally has kept pace. Scientists in many disciplines and a sizable proportion of the general public have identified the «;population explosion»; and the «;ecological crisis»; as critical problems requiring immediate attention. Some have suggested, and these views have been well received, that population size is «;causing»; the ecological imbalance. But the impact of human population growth on the problems mentioned above depends upon a vast number of factors, including the level of technology in a society, the nature of its social organization, its power relative to other human societies, its marital and reproductive practices, and its institutions of socialization.
Economists point to four stages in the «;demographic transition.»; In preindustrial societies high death rates balance high birthrates, ensuring steady population. In the second stage---early industrial development---better health lowers death rates, so birthrates appear excessive, and population spurts upward. Since Malthus collected his data in such an era, he did not and probably could not have seen what would come next. In the third stage, the security derived from urbanization, education, and affluence persuade many people to have fewer children. Thus the death rate continues falling but so does the birthrate, which flattens the population curve. Finally, in a mature society, with successful birth control and often with both spouses gainfully employed, couples seem to desire between one and three children, and the population stabilizes.
Another «;fact»; accepted without question in many quarters is that high human density is bad. A few animal studies on crowding (of questionable generality for other animal species, let alone for human population) are quoted repeated to make the point that overcrowding produces pathological behavior. Nevertheless, people crowd to the cities, because on balance they find life there more rewarding than in other locales. In fact, there is evidence that from a number of points of view, urban life-high density living-is good for people.