जनसाङ्ख्यिक सिद्धान्त

(b) Five stages

C.P. Blacker (1947) divided the demographic transition into five stages: (i) high stationary, (ii) early expanding, (iii) late expanding, (iv) low stationary, and (v) declining.

Malthus's theory, though influential, has been widely criticised on the following grounds:

1. Based on unrealistic assumptions. Malthus assumed that population grows in geometric progression (2, 4, 8, 16…) while food supply grows in arithmetic progression (2, 4, 6, 8…). No country has actually experienced such rigid and separate growth rates, so the assumption is unrealistic.

2. Food supply is not limited to arithmetic growth. Malthus ignored scientific and technological progress in agriculture. Improved seeds, chemical fertilizers, irrigation and mechanisation have raised food production far beyond his arithmetic rate, as seen in the Green Revolution.

3. Population growth is not automatic or unchecked. Malthus treated the tendency to multiply as a natural law. In reality, people control family size through family planning, contraception, late marriage and education, so population growth is a matter of choice, not compulsion.

4. Poverty is not caused by population alone. Malthus blamed population growth for poverty, but poverty also results from unequal distribution of resources, unemployment, low productivity, social injustice and poor government policy. Overpopulation is often a symptom rather than the sole cause.

5. Checks on population are not always "natural". Malthus classified checks as preventive and positive (famine, disease, war). In modern times, preventive checks such as family planning and rising living standards have reduced birth rates without the misery he predicted. Moreover, many developed countries have low birth rates despite high food supply, contradicting his theory.

6. Ignores the role of migration and trade. A country need not depend only on its own food; it can import food and migrate people. Malthus ignored international trade and migration as safety valves.

7. Not applicable to all stages of development. The theory fits only the pre-industrial stage. As societies develop, birth rates fall (demographic transition), so the fear of unlimited growth does not hold for developed nations.

(Any five points may be written.)