An increase in the population of a country is ascertained by only three factors: Fertility, mortality and migration. For the growth of population in India, migration has never been an important factor.
The contribution of the other two factors, fertility and mortality, has therefore to be considered. R.A. Gopalaswami, Registrar-General and ex-officio Census Commissioner of India, 1951, has explained the reason for the sharp differences in population growth during these two periods of thirty years, that is, 1891 to 1921 and 1921 to 1951, in a very lucid manner.
He concludes, “There is no reasonable doubt that the startling differences in the numbers added to the population during the two thirty-year periods are real.
The explanation would be simple if we draw a distinction between what may be called ‘normal deaths’ and ‘abnormal deaths.’ It is correct that child-bearing habits have not materially changed.
It is also correct that the incidence of normal deaths has slightly diminished but not sensationally. The diminution in the incidence of normal deaths is wholly insufficient to account for the contrast between the two periods.
The main explanation is that ‘abnormal deaths’ used to claim a great many victims in the earlier period. They did not occur or were prevented from occurring during the later period.”
When the estimates of the average birth and death rates in India are examined, it is clearly seen that while death rates have sharply declined in each successive decade up to 1951, birth rates have virtually remained unchanged up to 1961.
The striking fact is that while during 1911-1921 the death rate was 48.6 per thousand populations, during 1921-1931 it fell down to 36.3 a substantial decrease of 25.3 per cent.
A further decline of nearly 14 per cent was observed for the period 1921-1931 to 1931-1941. It is estimated that, during 1961-1971, the death rate in India was 19.0 per thousand population.
Thus, in the course of 50 years, a decline of 60.1 per cent has been observed in the death rate.
The expectation of life at birth, which was 18.1 years for males and 18.5 years for females during 1911-1921, rose to between 46 and 47 for males and between 44 and 45 for females during 1961-1971.
The reasons for this dramatic decline in mortality may once again be enumerated.
It must be noted that the ill effects of severe famines have been considerably reduced by preventive and relief measures; the dreaded disease of the plague has become extinct; cholera has been brought under control, small-pox has been eradicated from the Indian sub-continent according to the reports of the World Health Organization, and malaria, which is an extremely debilitating disease, has been brought under control.
Public health measures and the advancement in medical science mainly imported from the developed countries have further contributed to the reduction in mortality levels of India.
While the decline in mortality levels has been impressive during the last 50 years, the same cannot be said about the birth rates.
The estimated birth rate was 49 per thousand populations for the decade 1911-1921; it was around 45 for 1951-1961 and 41 for 1961-1971. Thus the decline in birth rate over a period of 50 years was only 16.3 per cent. The decline from the decade 1911-1921 to 1951-1961 has been negligible.
The above discussion highlights the fact that what has been responsible for the great upsurge in population growth in India is the substantial decline in mortality levels, specially after 1921, and a virtual maintenance of the fertility levels.
It is, therefore, obvious that if the rate of population growth in India is to be checked, the birth rate must necessarily be arrested and brought down.