Discuss the rationale behind periodic revision of base years for key economic indices in India. Examine the implications of the new base year (2022-23) for the Index of Core Industries.

Q. Discuss the rationale behind periodic revision of base years for key economic indices in India. Examine the implications of the new base year (2022-23) for the Index of Core Industries. (15 marks, 250 words)

Base years anchor economic indices to a reference period; over time they drift from the real economy's structure. In 2026 India synchronously rebased GDP, IIP, WPI/PPI and the Index of Core Industries (ICI) from 2011-12 to 2022-23, with the first revised ICI release on 20 July 2026 [1].

Rationale for periodic base-year revision - Representativeness: updated weights capture the current output mix, correcting an obsolete 2011-12 basket [2]. - Comparability: a common base across GDP, IIP, WPI and ICI keeps India's index ecosystem internally consistent [1][3]. - Methodological hygiene: revision allows cleanup of double-counting and definitional gaps [1]. - Post-pandemic realism: 2022-23 offers a stable, more contemporary reference than the disrupted COVID years.

Implications for the Index of Core Industries - Wider coverage: core industries rise from 8 to 9, with Iron Ore added, reflecting upstream mining's growing weight [1]. - Reweighting: Electricity (30.9%) overtakes Refinery Products as the highest-weighted sector, altering the index's sensitivity [1]. - Cleaner methodology: Steel shifts from net to gross production and Coal to raw-coal-only, aligning ICI with the new IIP series [1][3]. - Continuity: a linking factor (1.47) splices old and new series for long-run analysis [1]. - As a lead indicator for IIP (~40% weight), a sharper ICI improves early reading of industrial momentum [2].

Periodic rebasing is thus a routine yet vital exercise that keeps statistics credible; the coordinated 2026 revision strengthens evidence-based policymaking and aligns India's data architecture with a modern industrial economy.

(~250 words)

Sources: 1. First Press Release of Index of Core Industries of New Series with Base Year 2022-23 (PIB, 20 July 2026) — new base year, 9 core industries, Iron Ore, weights, gross-steel/raw-coal methodology, linking factor 1.47 2. Index of Eight Core Industries (Base: 2011-12=100), December 2025 (PIB) — old 8-industry basket, 40.27% IIP weight, ICI as IIP lead indicator 3. First Press Release of All India IIP of New Series with Base Year 2022-23 (PIB/MoSPI) — coordinated IIP rebasing, ICI weights derived from new IIP series