Life expectancies at older ages in destabilized populations: a methodological investigation with application to some developed and less developed countries

Subrata Lahiri, International Institute for Population Sciences (IIPS)

This paper presents a technique for estimating the ratios e(x+10)/e(x) over ages from two enumerations in a closed population following Generalized Population Model, which, in turn, are used to estimate life expectancies at older ages. The proposed technique makes use of an invariant property of the age-pattern of the ratio e(x+10)/e(x) over various mortality levels [e(0)] within a specified model mortality pattern. To test the validity of the procedure, the present technique has been applied to different quality of age-data starting with the age-data of Japan (1965-70) having reasonably good age-reporting followed by those of Korea (1990-95) and China (1982-90) with moderate error in age-reporting, and finally with those of India (1981-91) that are heavily distorted due to age-misreporting. The estimated e(x) values at older ages, so obtained, are sufficiently close to those obtained through life tables based on age-specific death rates for the above countries during the afore-mentioned periods.