Examine why base-year revisions in national income accounting do not follow a uniform direction across countries, with reference to India's 2022-23 base revision.

Rebasing realigns national accounts to a more recent "normal" year's price structure, output composition and survey frame. MoSPI replaced the 2011-12 series with a 2022-23 base on 27 February 2026 [1]. Since rebasing corrects whatever the old base mismeasured, its direction is country-specific, not systematic.

Why the direction is not uniform

• Nature of the earlier gap: where an old base omitted fast-growing sectors, rebasing raises GDP; where it over-extrapolated stagnant activities, it lowers it. Nigeria's 2014 rebasing, which folded in telecom and entertainment, sharply raised measured GDP [4].
• Quality of the new data frame: better enterprise and employment surveys can replace proxy indicators in either direction. India used ASUSE, the largest annual enterprise survey covering unincorporated non-agricultural establishments [5], to re-measure informal services.
• Choice of base year: a post-shock or inflation-distorted year yields a different level than a stable one; MoSPI defended 2022-23 as a post-pandemic year with comprehensive data [2].
• Classification and method: India's series adopted NIC-2025 and replaced single deflation with double deflation in manufacturing and agriculture [2] — changes that alter levels independently of the base shift.

India's case examined Nominal GDP for the overlap years was revised downward even as growth was revised upward — FY 2025-26 real growth at 7.6% and nominal at 8.6%, above the old-base estimates [1]; base-year GDP stands at ₹261.18 lakh crore, with 7.2% and 7.1% real growth in FY24 and FY25 [3]. MoSPI clarifies that the gap reflects new data and methods jointly, not an engineered revision [2].

Implications A smaller nominal denominator inflates fiscal deficit-to-GDP and debt-to-GDP ratios without any change in borrowing, and breaks series comparability until the back series is published [2].

Base revisions are therefore statistical hygiene, not verdicts on performance. Timely rebasing — ideally synchronised across GDP, CPI, WPI and IIP, with a reconciled back series — would strengthen the credibility of official statistics that underpins evidence-based policymaking.