OPTIMUM POPULATION THEORY

Introduction

The relationship between population and resources forms the basis of the optimum population theory. The optimum theory of population was propounded by Edwin Cannon, an English Economist in his book ‘Wealth’ published in 1924 and popularized by Robbins, Dalton and Carr Saunders. The optimum population is the ideal population which combined with other available resources for means of production of the country will yield the maximum returns or income per head.

The first beginning of this concept may be  traced to the writings of a German professor, Karl Winkalblech (1810-1865) who while describing population theory and policy, classified nations into three categories according to the size of their population:

• Under-populated Nations
• Over-populated Nations
• Nations with normal populations,  meaning a size favourable to the greatest possible productivity.

Cannan used the term “optimum population” as synonymous with the best possible population, and clarified in the following words; "At any given time, the population which can exist on a given extent of land, consistent with the greatest productiveness of industry at that time, is definite."

The concept of optimum population has been defined differently by Robbins, Carr Saunders and Dalton.

Robbins defines it as “the population which just makes the maximum returns possible in the optimum population or the best population.”

Carr Saunders define it as “that population which produces maximum economic welfare.”

According to Dalton, “optimum population is that which gives the maximum income per head.”

Some writers considering the concept of the economic optimum as being too restrictive, have included in it the total well-being, health, longevity of a nation, the ideal family size, the conservation of natural resources, power, defence and other spiritual, cultural and aesthetic factors.

Assumptions:

This theory is based on the following assumptions:

1. The natural resources of a country are given at a point of time but they change with time.
2. There is no change in techniques of production.
3. The stock of capital remains constant.
4. The habits and tastes of the people do not change.
5. The ratio of working population to total population remains constant even with the growth of population.
6. Working hours of labour do not change.
7. Modes of business organisation are constant.

Given these assumptions, the optimum population is that ideal size of population which provides the maximum income per head. Any increase all decrease in the size of population above or below the optimum level will diminish income per head. Given the stock of natural resources, the technique of production and the stock of capital in a country, there is a definite size of population corresponding to the highest per capita income. Other things being equal, any deviation from this optimum sized population will lead to a reduction in the per capita income. If the increase in population is followed by the increase in per capita income, the country is under-populated and it can afford to increase its population till it reaches the optimum level. On the contrary, if the increase in population leads to diminution in per capita income, the country is over-populated and needs a decline in population till the per capita income is maximised. This has been illustrated in the following diagram:

But the optimum level is not a fixed point, it changes with a change in any of the factors assumed to be given. For instance, if there are improvements in the methods and techniques of production, the output per head will rise and the optimum point will shift upward. What the optimum point for the country is today, may not be tomorrow, if the stock of natural resources increases and the optimum point will be higher than before. This is shown in the following figure:

 

Dalton has deduced over-population and under-population which result in the deviation from the optimum level of population in the form of a formula. The deviation from the optimum, he calls maladjustment. Maladjustment is a function of two variables, the optimum level of population (O) and the actual level population (A). Then the maladjustment is:

When M is positive, the country is over-populated, and if it is negative, the country is under-populated. When M is zero, the country possesses optimum population. Since it is not possible to measure O, this formula is only of academic interests.

However, John I. Clarke distinguishes between the absolute and relative over-population. The absolute over-population is one where the living standards remain low even after the attainment of absolute limit of resource development. Relative overpopulation is the one where the present level of production is inadequate for the population but greater production is feasible. Relative overpopulation is more common than the absolute overpopulation. Relative under-population like relative overpopulation, is more common than absolute underpopulation. Absolute underpopulation will occur only in isolated areas where the degree of replacement of population is less than unity. Relative underpopulation takes place where there is insufficient development of resources.

Criticism:

1. It is impossible/difficult to measure qualitatively the optimum level of population.
2. The correct measurement of per capita income in a country is also not an easy task.
3. It neglects the horizontal and vertical distributional aspects of increase in per capita income.
4. The optimum level of population is not fixed but oscillating.
5. The theory fails/neglects to take into consideration the social and institutional conditions which greatly influence the level of population in a country.
6. The theory does not explain the reasons for rise or fall in birth and death rates, the impact of urbanization and migration on population growth etc.
7. It does not explain how the optimum level once reached can be maintained.