Note on Population Theory

  • Note
  • Things to remember

There are two well-known theories of population. They are:

  • Malthusian Theory of Population
  • Optimum Theory of Population

Malthusian Theory of population

Malthusian theory of a population is the most well-known theory of population. This theory was developed by T.R Malthus. According to him, population growth is directly associated with food supply. He gave his view in his book “Essay on the principle of population “published in 1798. His idea can be summarized in the given points:

Food Supply

Malthus says the food production can be increased in slow rate which according to him can be marked by the thematic progression like 2, 4, 6, 8. This is because the agricultural productivity follows the denomination rate of return (i.e higher the % of input use, the rate of return will be lesser and lesser)

Population Growth

Malthus says that population growth is the strong instinct among the people, so population increases at the faster rate. According to him, population increases in a geometric ratio like 2, 4, 8, 16, and 32---- Basically, the population growth tends to be higher when people have enough food for them. Malthus says due to rapid population growth the population will be double in every 25 yrs.

Due to the imbalance between the high population growth and slow increase in food production, their arises the scarcity of food and many problems come up with it which lead to the population growth control. Malthus has identified two ways of population control:

  • Positive checks:

It means the natural way of population control which includes famines, natural disaster, climate change, criminal activities and even war. According to Malthus, when there is an explosion of the population it is automatically balanced by nature. Due to the scarcity of food, the people may suffer from malnutrition, famines, and overuse of natural resources may give rise to natural disasters. Similarly, the over competition to acquire enough food and high living standard give rise to criminal activities and war. Due to this reason, a large number of population died and the population level may come down to the reasonable size.

  • Preventive checks:

When people die due to natural phenomenon created by food shortage, it is very painful for the friends and relatives associated with them. So, people become aware themselves to control high population growth in order to minimize such painful moment. The attempt of people to control the population in a natural way is called preventive checks. It includes late marriage, celibacy, maintaining a culture and religious norms etc. Malthus, however, has denied the role of using artificial family planning devices to control the population.

Criticisms of Malthusian Theory of population

The Malthusian Theory has been criticized by various economist under the following points:

  • Problem not due to population:

Karl Marx saw nothing wrong with the use of birth control and the problems would not arise due to population numbers, but due to disorganization of the population.

  • Failure to Realize the possibility of scientific development:

Malthus failed to realize the possibilities of inventions, practices, and technological trends that help to monitor and improve the population's food supply.

  • Failure to accept modern means of birth control:

There is also the issue of refusal to accept birth control and the positive effects it could have on the growth of the population. Birth control is widely used and encouraged today for various reasons.

  • Wrong numerical ratios:

Malthus stated that population increases in a geometric ratio whereas the food supply increases in an arithmetic ratio.But there is no history behind this statement.

  • Pessimistic theory:

This theory of population is criticized on the ground of its pessimism. According to this theory, the increase in population invites evils in the economy. But cannot believes in the fact that “A baby comes to the world not only with a mouth and a stomach but also with a pair of hands"

Optimum theory of population

The concept was originated by Edwin Cannan and developed by Dalton, Robbins, etc. Malthus has pointed out every population growth as a problem but this theory says that every population growth is not the problem as higher population size is also needed for economic development. It has pointed out three stage of population:

1. Underpopulation:

It is that size of a population which is insufficient to utilize the available resources at maximum. In this stage, resources are lying idle due to less number of manpower. As a result, the per capita income also becomes less.

2. Optimum population:

It is that population size which is just enough to utilize the physical resources at maximum. In this situation, there are no idle resources and there is no problem of unemployment. The per capita income also reaches a maximum.

3. Overpopulation:

When the population size exceeds the available resources there is a problem of unemployment along with food scarcity, malnutrition, and other social problem. The per capita income also reduces due to the population pressure.

Dalton's equation:



M= Maladjustment factor

A=Actual size of population (Existing)

Op=Optimum population size


A>Op = M>O = Over population

A<Op = M<O = Under population

A=Op = M=O = Optimum population

Up to Op level, increases in population lead to a rise in the average product of labor and per capita income>beyond OP, the average product and per capita income fall. To the left of OP, the country is under populated and beyond OP, the country is under populated and beyond OP, it is over populated .In the figure, AP come represents the higher average product of labor and point <,shows the maximum per capita income at the optimum level of population OP.

Criticisms of Optimum Theory of Population

Some major criticism of optimum theory of population are as follow:

  • No Evidence of optimum level:

The fist weakness of the optimum theory is that it is difficult to whether there is anything like an optimum population. There is no evidence about the optimum population level in any country. In fact, it is impossible to measure it.

  • Correct measurement of per capita income not possible:

Another difficulty pertains to the measurement of per capita income in the country. It is not an easy task to measure changes in the per capita income.

  • Neglects the distributional aspect of increase in Per-capita Income:

Even if it is assumed that per capita income can be measured, it is not certain that the increases in population accompanied by the increase in per capita income would bring prosperity to the country.

  • Neglects social and institutional conditions:

The optimum theory considers only the economic factors which determine the level of population. Thus, it fails to take into consideration the social and institutional conditions which greatly influence the level of population in a country.

(Karna, Khanal, and Chaulagain)(Khanal, Khatiwada, and Thapa)(Jha, Bhusal, and Bista)


Jha, P.K., et al. Economics II. Kalimati, Kathmandu: Dreamland Publication, 2011.

Karna, Dr.Surendra Labh, Bhawani Prasad Khanal and Neelam Prasad Chaulagain. Economics. Kathmandu: Jupiter Publisher and Distributors Pvt. Ltd, 2070.

Khanal, Dr. Rajesh Keshar, et al. Economics II. Kathmandu: Januka Publication Pvt. Ltd., 2013.

  1. Malthusian theory of population and Optimum theory of population are the well-known theory of population.
  2. Malthusian theory was developed by T.R Malthus. 
  3. Optimum theory of population was originated by Edwin Cannan and develops by Dalton, Robbins, etc. 

Criticism of Malthusian theory of population

  1. Problem not due to population
  2. Failure to Realize the possibility of scientific development
  3. Failure to accept modern means of birth control
  4. Wrong numerical ratios
  5. Pessimistic theory

Criticism of Optimum theory of population

  1. No Evidence of optimum level
  2. Correct measurement of per capita income not possible
  3. Neglects the distributional aspect of increase in Per-capita Income
  4. Neglects social and institutional conditions



Very Short Questions



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Chandra gaire

Who and when did this theory produced?

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