Operational Equity and Data Quality in India's Aadhaar System

India’s Aadhaar program, the largest biometric identity system globally, reports saturation levels exceeding 100% in several states. While near-universal coverage is often celebrated, less is known about operational equity and data-quality challenges in ongoing maintenance- biometric updates, demographic corrections, and benefit scheme enrolment. This study analyzes March 2025 records of Aadhaar biometric updates, demographic updates, and new enrolments, normalized by state-level saturation data from UIDAI. In the absence of state-level biometric authentication logs, we use adult biometric update rates as a proxy for verification activity. Both raw and sensitivity-capped measures are applied to account for oversaturation. Correlation and regression models, alongside uncertainty quantification, reveal that high Aadhaar coverage does not guarantee scheme uptake or robust data integrity. Oversaturation emerges as a key stress signal, and persistent last-mile gaps remain for vulnerable, less urbanized regions. Policy recommendations focus on registry hygiene, targeted outreach, and transparent operational monitoring.