Ranking Reliably in Health Inequality Measurement: Anchor-Calibrated Economic Ranking for Correcting Survey Measurement Error in Income and Wealth Values Among Older Adults in India

This paper investigates whether survey measurement error in welfare rankings conceals the true extent of socioeconomic health inequality among older adults in India, using nationally representative LASI Wave 1 data. We develop an anchor-calibrated composite economic ranking that corrects systematic underreporting in self-reported income and gross asset values using consumption and a PCA wealth index as stable anchors. Probit models, doubly robust IPWRA estimators, and Erreygers-corrected concentration indices are estimated across five health outcomes and seven welfare specifications. Raw income produces null or directionally misleading gradient estimates for most outcomes, including a sign reversal in the income–self-rated health association. Anchor calibration consistently recovers larger and more plausible gradients, with concentration index amplification ranging from 12% to 46% across outcomes, while for multimorbidity, raw income entirely masks a statistically significant pro-rich gradient. Decomposition analysis reveals that education is the dominant driver of functional and subjective health inequality, whereas direct SES is the dominant driver of nutritional inequality. Results survive robustness checks across alternative anchor weights, thresholds, and estimators and imply that inequality-monitoring systems based on raw income systematically understate health disparities among older Indians.