Compare the methodological approach of the Index of Services Production (ISP) with the Index of Industrial Production (IIP).

The Index of Services Production (ISP), released by MoSPI with base year 2024-25, is designed as the services-sector counterpart of the Index of Industrial Production (IIP) [1]. While it borrows IIP's fixed-base weighted architecture, it diverges sharply in data sourcing and measurement — reflecting both continuity and innovation in India's statistical system.

Shared methodological foundations

• Both are fixed-base weighted indices, with weights drawn from each sub-sector's share in base-year Gross Value Added under National Accounts Statistics [1][3].
• Both are monthly short-term indicators compiled by MoSPI/NSO, built up from disaggregated sub-sector indices aggregated into a headline number [1][3].
• Both measure real output (volume), not nominal value, and both follow a near month-end release calendar — IIP on the 28th of every month [4], ISP proposed for the 29th [1].

Points of divergence

• Base year: IIP retains 2011-12 [3], whereas ISP adopts 2024-25, deliberately synchronised with the new CPI base (2024) because CPI-based deflators are used for most sub-sectors [1].
• Measurement technique: IIP captures physical quantity of items produced; services output cannot be physically counted, so ISP deflates value/turnover data to derive volume [1].
• Data source: IIP draws on returns from designated source agencies; ISP innovatively uses administrative and digital data — GST returns and ASISSE-type enterprise surveys [1][2].
• Coverage: IIP spans mining, manufacturing and electricity comprehensively; ISP's trial covers only 19 sub-sectors (~60% of formal services), with health and education deferred pending ASISSE results [1][2].
• Maturity and lag: IIP is a settled official statistic; ISP remains an experimental "trial" index, preceded by an Approach Paper and a Technical Advisory Committee, and carries a longer ~60-day lag [1][2].

ISP thus adapts IIP's proven index logic to the intangible nature of services, substituting deflated administrative data for physical counts. Refining coverage, shortening the release lag and stabilising deflators will be key before full launch. Once mature, ISP will complete India's short-term indicator framework, enabling more evidence-based monetary and fiscal policymaking.