Assessment of Model Life Table Methods for Estimating Life Expectancy at Birth in India

Abstract

Model life tables provide an effective approach for estimating age-specific mortality patterns when only summary mortality indicators are available. This study used data from the National Family Health Survey (NFHS-4: 2015-16; NFHS-5: 2019-21) and the Sample Registration System (SRS: 2015 and 2020) to estimate life expectancy at birth in India. Four model life table approaches-Brass Logit, Modified Logit, Splicing, and Log-Quadratic-were applied using under-five mortality (U5MR) and adult mortality estimates. Model performance was evaluated at national and state levels by comparing estimated and observed life expectancy. Among the evaluated models, the Brass Logit model showed the highest predictive accuracy, with estimates closely matching empirical life expectancy, while the Log-Quadratic model also performed well in capturing age-specific mortality patterns. The findings suggest that the Brass Logit model is the most reliable approach for estimating life expectancy and mortality schedules in India when detailed age-specific mortality data are unavailable.