The Malthusian Theory is a theory of population growth. It discusses the rate of growth of population and the effects of such growth on the community.
The Optimum Theory is not a theory of population growth. It discusses the relationship between the number of people living in a country and its productive resources.
2. Food supply v. total output:
Malthus concentrated attention on food supply. The Optimum Theory concentrates attention on the total output, industrial as well as agricultural.
Over-population v. Optimum population:
Malthus defined over-population in terms of food- supply. A country is over-populated if it does not produce enough food to feed its population. The Mydral, Population-A Problem for Democracy. Optimum Theory defines over-population in terms of productivity. A country is over-populated if it contains more people than what is required for the best utilisation of its productive resources.
Pessimism v. Optimism:
Malthus was a pessimist. He made the gloomy prophecy that men are bound to go through the cycle of over-population, misery, death, a short period of balance between food and population and again over-population. The Optimum Theory is highly optimistic. According to it, there is no danger from population increase so long as it does not exceed the number required for the optimum utilisation of the productive resources of the country.
5. Dynamic theory v. Static approach:
The Malthusian Theory is a dynamic theory. It deals with the course of population growth over a period of time.
The Optimum Theory is static in its approach. It considers the population problem with reference to a particular stage in the country’s development. The optimum population is calculated with reference to the productive resources available at a particular time.