The Malthusian theory of population growth was propounded by the English political economist Thomas Robert Malthus. It was a pessimistic theory where he argued that human population tends to grow at a faster rate than the rate at which the means of human subsistence, especially food, and agricultural products along with clothing, grow. The uncontrollable population growth can lead to environmental degradation, economic crisis, and puts a strain on the resources, agricultural outputs, infrastructures, governmental institutions, society, etc.
Although this unprecedented growth has slowed down in the developed countries, in the developing countries the ill effects of population explosion still loom large. Therefore, Thomas Robert Malthus came up with a theory that studies the relationship between resources and population growth.
According to him, the population can grow uncontrollably due to the natural sex instinct in human beings increasing at a fast rate. It grows in the geometric progression, (2, 4, 8, 16, 32…), and is very fast. On the other land gives a limited return and grows at a rate of arithmetic progression, i.e. (2, 4, 6, 8, 10…), which is very slow. This is due to the law of diminishing returns based on the notion that the supply of land is constant. Since population according to Malthus grows without any control, land is not able to sustain a large population and hence it leads to poverty, hunger, starvation, etc. This results in an imbalance that causes overpopulation or population explosion.
He came up with two kinds of solutions, positive check, and preventive check. He believed that, through these measures, the population would be controlled and the food supply would be balanced with the population level. His solution to the positive check was active in nature. Natural disasters cause death to many people and hence population is naturally controlled. Other positive checks include epidemics, famine, warfare, etc. ‘If one does not take care of themselves, nature knows how to take care of them’. Malthus views that positive checks can result in a Malthusian catastrophe or crisis that can force the population to return to its basic survival.
The preventive check includes the man-made means by which the population is controlled. They can be used by people voluntarily in order to control the population. This includes contraceptive pills, late marriages, celibacy, etc.
Malthus argued that preventive checks are always operating in a civilized society. He appealed that to keep a check on the population growth and control overpopulation, it is essential for the people to adopt the preventive checks.
The theory of Malthus was criticized by many theorists as well. According to sociologists, poverty, hunger, etc are not due to less agricultural growth but due to unequal economic resources. Again, agricultural production is not limited due to the advancement of science and technology. Along with population growth, there is an increase in the standard of living, due to advancement in science and technology. They also criticized the mathematical reasoning provided by him. They called his theory pessimistic because he only saw the negative aspect of population growth by neglecting the growth of manpower.