Propositions of The TheoryThe theory propounded by Malthus can be reduced to the following four propositions:
1. Food is necessary for the life of a man and therefore exercises a strong check on population. In other words, the size of population is determined by the availability of food.
2. Human population increases faster than food production which tends to out turn the increase in food production.
3. Population always increases when the means of subsistence increase unless prevented by some powerful checks.
4. There are two types of checks that can keep population on a level with the means of subsistence. They are preventive and positive checks.
The explanation of the propositions is:
Means of Subsistence
According to the first proposition, the population of a country is limited by means of subsistence i.e. the population is determined by the availability of food. The greater the food production, the greater would be the population and vice versa.
Growth or Population Outruns Food Production
According to Malthus, there is no limit to the fertility of man. Man multiplies itself at an enormous rate. But the power of land to produce food is limited. It means that the production of land increases at a lesser rate as compared to production of man. Thus, the continued growth of the population would result in a decrease in output per worker and a decline in the amount of food available per person.
Population Increases When the Means Increase
According to third preposition as the food supply in a country increases, the member of children per family also increases. It, therefore, would result in an increased demand for food and their food per person will diminish. Thus, according to Malthus, the standard of living of the people cannot rise permanently.
According to Malthus, contain positive and preventive checks can control the population. Preventive checks are those that are applied by man and includes measures for bring down the birth rate. The positive checks on the other hand exercise their influence on the growth of population by increasing death rates. They are applied by nature. Epidemics, wars and famines are some examples of positive checks.
Optimum Or Modern Theory Of Population
According to the theory, given a certain amount of resources, the state of technical know-how and a certain stock of capital, a country must have a certain size of population at which the real income (goods and services) per capital is the highest. This size of population is called optimum population. In other words, optimum population refers to a size of population at which the real income per capital is the maximum. If population exceeds the optimum size, it is said to be over populated. Such a condition develops in a country. When it’s available resources are fully exhausted and there exists no chance of their further exploitation. It is necessary at this stage that the country must practice preventive checks and to escape from the misery of positive checks.
According to this theory, there are three phases population in a country viz.
(a) Under Population
A condition at which real per capital income rises with a rise in the size of population.
(b) Optimum Population
A situation at which real income per capital is the highest.
(c) Over Population
From under and optimum population, a country moves, unless preventive checks are applied, to the level of over population, at which the real income per capital diminishes.