Critically evaluate the institutional mechanism (MoSPI, NSO, Expert Groups) for periodic revision of macroeconomic indices in India.

Macroeconomic indices anchor policy — the RBI's flexible inflation target of 4% ± 2% rests entirely on the CPI. India's revision mechanism, centred on MoSPI, its National Statistical Office (NSO) and expert groups, was tested by the CPI base shift from 2012=100 to 2024=100 [2]. It has matured substantially, though gaps in periodicity and comparability persist.

Strengths of the mechanism

• Evidence-based weights: CPI 2024 weights are drawn from the Household Consumption Expenditure Survey (HCES) 2023-24, with base prices collected through January–December 2024 to match the survey's reference period [2].
• Consultative expert route: the base revision was vetted by an Expert Group including RBI, academia, line ministries and statistical experts, aligning statistical design with monetary-policy needs [2].
• Contemporary basket: items expanded from 299 to 358 (goods 259→308; services 40→50), adding rural housing and streaming services while dropping VCRs and cassettes [2].
• Robust field architecture: NSO's Field Operations Division collects prices by weekly personal visits from 1,407 urban markets and 1,465 villages, recording a 100% response rate in July 2026 [1].
• Predictable disclosure: calendared mid-month releases with a provisional–final revision cycle (July 2026 combined inflation 4.45% against June's final 4.38%) [1].

Persisting weaknesses

• Long revision lag: over a decade separated the 2012 and 2024 bases, while consumption and digital services changed rapidly [2].
• Break in comparability: figures across base series are not directly comparable, complicating long-run trend analysis.
• Single-source dependence: weights hinge on one HCES round, so survey delays transmit straight into the index.
• Aggregation masks divergence: Telangana's 6.32% against the national 4.45% shows regional price realities the headline hides [1].
• Ad hoc bodies: Expert Groups are constituted per revision, lacking statutory permanence and continuous institutional memory.

The mechanism is technically sound and increasingly consultative, yet episodic rather than routinised. A fixed statutory revision cycle, more frequent consumption surveys and published back-cast series — under National Statistical Commission oversight — would make India's indices durable public goods for evidence-based policymaking.