Malthus’ theory is based on three postulates or assumptions :
1 – Food is a vital necessity
2 – People will continue to reproduce and population will grow geometrically and double every 25 years.
3 – The law of diminishing returns applies to agriculture and grows arithmetically.
Population increase cannot be met with a corresponding increase in food production and therefore famines may ensue.
To avoid this, Malthus suggested the use of positive checks and preventive checks.
Positive checks are essentially misery, famine, natural disasters and war.
Preventive checks consist in a variety of methods to prevent high fertility rates and includes celibacy and late marriage.
There are several flaws in the theory:
- Population has not expanded geometrically and food production has increased massively, in particular due to technological improvements
- New geographic areas have opened and have proved to be large food suppliers
- Population increases may lead to a demographic dividend
- Population increase has been due mostly to the extension of life rather than to an increase in birth rates
- Increase in family income reduces fertility as the cost of bringing up children in a more expensive social environment increases
- Efficient family planning methods were developed as preventive checks.