Vital rates of India for intercensal period with declining fertility and declining mortality
Das, N.C.
Genus 48(1-2): 199-215
1992
ISSN/ISBN: 0016-6987 PMID: 12317868 Document Number: 325422
This paper presents estimation of vital rates of the population of the 1981 census in quasi-stable state by adjusting estimates based on the stable population model for effects of declining fertility as suggested in the U.N. Manual IV. The decadal growth rate of population and the age distribution from the 1921 census through the 1971 census makes it evident that mortality has been improving since 1921 while fertility remained constant over the 1921-71 period in India. the decadal growth rate of the population and the age distribution for the 1981 census indicate that the destabilization of the population during the 1971-81 intercensal period was brought out by declining fertility and declining mortality. The rise in the proportion of population aged 60 years and above from 4.1% in the 1931 census to 6.49% in the 1981 census indicates a steady improvement in mortality during the period of 1931-1981. The Sample Registration System (SRS) was launched in India in the mid-1960s to furnish plausible estimates of annual rates of vital events. The SRS estimate of birth rate for 1980-82 was 35.4 for the rural population, 27.6 for the urban population, and 33.6 for the whole population, as opposed to the quasi-stable estimates of 37.5, 30.8, and 36, respectively. Thus, the birth rate for 1980-82 was underestimated in the SRS by a margin of 6%, 10%, and 7% for the respective populations. The SRS estimate of death events for 1980-82 was 13.5 for the rural population and 7.7 for the urban population. By weighing proportions of rural and urban population to total population in the 1981 census, the death rate for the whole population for 1980-82 was estimated at 12.2 as opposed to the quasi-stable estimate of 14.5. Thus, the death rate was underestimated in the SRS by a margin of 16%. In sum, the rate for quasi-stable state for 1981 was estimated at 36 for birth events, representing a 7% underestimation by SRS and at 14.5 for death events, representing a 16% underestimation by SRS.