Inflation & Price Indices — CPI, WPI, Inflation Targeting

Introduction

Inflation — the sustained rise in the general price level — is one of the most closely watched macroeconomic variables. It erodes purchasing power, distorts savings and investment decisions, and disproportionately harms the poor. India's inflation architecture involves multiple price indices, a formal inflation targeting framework, and an institutional mechanism (the Monetary Policy Committee) to keep inflation within bounds. This topic is examined in both Prelims (data-based) and Mains (policy analysis) under GS3 Economy.

Consumer Price Index (CPI)

The CPI measures changes in the average retail prices of a basket of goods and services that households typically consume. It is compiled by the Ministry of Statistics and Programme Implementation (MoSPI).

CPI Components and Weightage

Old Series (Base Year: 2012=100) — superseded February 2026

Current Series (Base Year: 2024=100) — effective 12 February 2026

A new CPI series with base year 2024=100 was released by MoSPI on 12 February 2026. Key changes: basket expanded to 358 weighted items (from 299) using HCES 2023-24; classification updated to COICOP 2018; food & beverages weight reduced to reflect changed consumption patterns.

Exam note: The old 2012=100 series' 46% food weight is still tested in older UPSC questions. The new 2024=100 series' food weight (~37%) will feature in Prelims 2027. Always state which series when citing food weight. Food & beverages still carry the highest single-group weight, so food price shocks continue to strongly influence headline CPI.

Average CPI for FY 2024-25 was 4.6% (a six-year low). February 2026 CPI (first reading under new base) was 3.21% (rural 3.37%, urban 3.02%). March 2026 CPI: 3.4%; April 2026 CPI: 3.48% (provisional, MoSPI May 12, 2026) — food inflation 4.20% in April 2026, housing inflation 2.15%.

Types of CPI

CPI (Combined) is the measure used for India's inflation targeting framework under the RBI Act.

Wholesale Price Index (WPI)

The WPI measures price changes at the wholesale/producer level — before goods reach consumers. It is compiled by the Office of the Economic Adviser, Ministry of Commerce and Industry.

WPI Components and Weightage (Base Year: 2011-12=100)

Within Manufactured Products, the largest sub-groups are: Basic Metals (9.7%), Food Products (9.1%), Chemicals & Chemical Products (6.5%), Textiles (4.9%).

CPI vs WPI: Key Differences

GDP Deflator

• Measures average price change across all goods and services in the economy — the broadest price index
• = (Nominal GDP / Real GDP) × 100
• Covers both tradeable and non-tradeable sectors
• Not released monthly; derived from national accounts data
• Not used for inflation targeting but is important for understanding real vs nominal growth

Headline vs Core Inflation

The gap between headline and core inflation is important for monetary policy — if food prices spike but core remains low, the RBI may look through the headline shock rather than aggressively tightening.

India's Flexible Inflation Targeting Framework

Legislative Basis

The RBI Act, 1934 was amended in 2016 to formally mandate inflation targeting. Key provisions:

• Section 45ZA: Central government, in consultation with RBI, shall determine the inflation target every 5 years
• Section 45ZB: Constitutes the Monetary Policy Committee (MPC) to set the policy rate to achieve the target
• Section 45ZC: MPC members' qualifications and appointment process
• Section 45ZL: MPC must publish minutes (with individual votes) within 14 days of each meeting (Section 45ZI deals with quorum and decisions; Section 45ZN governs the failure-report obligation when inflation breaches the target band for 3 consecutive quarters)

Inflation Target

Monetary Policy Committee (MPC)

• Constituted: October 2016 (first meeting)
• Composition: 6 members — 3 RBI officials (including the Governor as Chairperson) + 3 external members appointed by the Central Government
• Decision-making: Simple majority; Governor has a casting vote in case of a tie
• Meetings: Minimum 4 times a year; meets every two months in practice
• Instrument: Sets the Repo Rate (key policy rate) — the rate at which RBI lends overnight to commercial banks

RBI Tools to Control Inflation

Causes of Inflation in India

Recent Inflation Trends in India (2024–2026)

RBI's revised inflation forecast for FY 2025-26: 2.1% (MPC February 2026 — revised down from 2.6% at December 2025, which was down from 3.1% at August 2025; the actual outturn tracked close to or below 2.1%, driven by an unprecedented 9-month food price decline).

WPI divergence — April 2026 surge: WPI inflation rose sharply to 8.3% (provisional) in April 2026 (Office of Economic Adviser, PIB), the highest in several months, driven by fuel and power (+24.71%), primary articles (+9.17%), and manufactured products (+4.62%). This reflects the global crude oil and fuel price spike — a significant WPI-CPI divergence given CPI remained at 3.48% in April 2026. The WPI food index was only 2.31% in April 2026 — confirming the WPI surge was fuel/input-cost driven, not food-driven.

RBI Rate Actions (2025): RBI reduced the repo rate by cumulative 125 basis points via four cuts in 2025 (Feb 25bps, Apr 25bps, Jun 50bps, Dec 25bps), bringing the rate from 6.50% to 5.25%, as easing inflation created space to support economic growth. The April 2026 MPC held the rate unchanged at 5.25%. Governor: Sanjay Malhotra (appointed December 2024).

Food Inflation — Structural Challenges

Food inflation is India's most persistent inflation challenge because:

• Food has a ~46% weight in CPI under the old 2012=100 series; ~37% under the new 2024=100 series (effective 12 February 2026) — still the single largest group, so any supply shock immediately shows in headline
• Perishables (vegetables, fruits) are highly price-volatile due to seasonal production cycles
• India lacks a robust cold chain and post-harvest infrastructure — large wastage amplifies supply shocks
• APMC (Agricultural Produce Market Committee) fragmentation raises intermediary costs
• Global edible oil and pulses prices pass through into domestic prices due to high import dependence

Cross-paper relevance

• GS3 — Indian Economy (primary) — CPI, WPI, GDP deflator, core vs headline inflation, RBI flexible inflation targeting (4% ± 2%), MPC, food inflation drivers
• GS3 — Agriculture: food price volatility, buffer stock policy, Essential Commodities Act
• GS2 — Governance: RBI's mandate, monetary policy framework, MPC composition and accountability
• Essay — "Inflation: silent tax on the poor"; "Balancing growth and price stability — RBI's tightrope walk"

Recent Developments (2024–2026)

CPI Inflation at 6-Year Low — Drivers and Structural Interpretation

The inflation trend data (FY25 average, monthly peaks, and recent readings) are summarised in the Recent Inflation Trends table above. The analytical story is the structural decomposition: headline CPI moderated sharply, but the reasons matter for policy.

The FY25 moderation was primarily food-supply-driven, not demand-destruction. Vegetable prices fell ~35% in early 2025 after a weather-induced spike — this kind of correction is inherently transient. Core CPI (excluding food and fuel) remained sticky around 3.5–4.0% throughout FY25, suggesting underlying demand-side inflationary pressure in services (health, education, recreation) and manufactured goods (autos, electronics). The wedge between food inflation and core inflation is the key diagnostic: when food falls but core stays elevated, it signals that the overall economy is not in deflationary territory — the moderation is supply-relief, not growth weakness.

WPI divergence from CPI is also analytically important. WPI averaged approximately 2.3% in FY25 (up from -0.7% deflationary dip in FY24). In FY26, WPI swung dramatically — near-zero/negative in mid-2025 (driven by falling crude and commodity prices globally) before surging to 8.3% in April 2026 (provisional, PIB/Office of Economic Adviser) — the highest in months, driven by fuel and power prices (+24.71%) following global crude oil price increases. CPI in April 2026 stayed at 3.48%, creating a sharp WPI–CPI divergence of nearly 5 percentage points — the starkest since 2022. WPI tracks input costs for producers; a surging WPI while CPI stays moderate means producer margins are being compressed — firms have absorbed cost increases without passing them to consumers. This is ultimately unsustainable: if WPI remains elevated, CPI will re-accelerate once inventory normalization occurs. This WPI-CPI lead-lag relationship is a recurring Mains analytical thread.

UPSC angle (Prelims 2027 / Mains 2026): The food-core inflation divergence (food deflationary Dec 2025 while core sticky at 3.5-4%), the WPI-CPI lead-lag relationship (WPI at 8.3% in April 2026 vs CPI at 3.48% — ~5pp divergence driven by fuel), and the "Tomato-Onion-Potato (TOP) problem" — why supply-side solutions (better cold chains, e-NAM, buffer stock policy) are necessary for durable inflation control — are strong Mains GS3 analytical frameworks beyond the headline numbers.

RBI's Inflation Targeting Framework — Has FIT Worked?

The FIT framework parameters (4% target, ±2% band, MPC composition, renewed mandate 1 April 2026–31 March 2031) are in the static sections above. The deeper question for Mains is: has the FIT framework actually worked?

The evidence is mixed but broadly positive. CPI has been within the 2–6% band for most of FY23-FY26, and FY25 ended at a 6-year low of 4.6% — a strong credibility signal. Governor Sanjay Malhotra (appointed December 2024) continued the institutional approach of his predecessor, initiating 4 rate cuts (125 bps total in 2025) as inflation space opened.

But three structural weaknesses persist in the FIT framework:

1. The food-inflation problem: With food at ~37-46% of the basket, supply-side shocks (monsoon, vegetable prices) frequently push headline CPI above 6%, triggering the failure-report mechanism — not because monetary policy failed but because it was never the right tool. The MPC's response to tomato-onion spikes is to "look through" them, which is analytically correct but publicly difficult to explain.

2. The target vs. tolerance confusion: Markets, governments, and media focus on the 4% target; the RBI's actual mandate is to keep inflation within the 2–6% band. The band was deliberately wide to account for India's supply-side volatility — but this creates a perverse incentive: the government cites FIT "success" when CPI is at 3.5%, while the inflation-targeting literature says that persistently below-target inflation (like December 2025's 1.33%) is also a failure mode, signaling deflationary risk.

3. Transmission problem: Rate cuts (repo down 125 bps in 2025) transmitted partially and unevenly to lending rates. The MCLR (Marginal Cost of Funds based Lending Rate) transmission lag — typically 6–12 months — means the 2025 rate cuts' full effect on credit and growth won't materialise until FY27.

UPSC angle: FIT's scorecard (successes and structural limitations), the food-inflation/monetary-tool mismatch, the target-vs-band distinction, and the rate transmission lag are all strong Mains GS3 analytical frameworks beyond the headline framework description.

New CPI Series (Base Year 2024) — Policy Implications of Revised Weights

The new CPI series (base 2024=100, released 12 February 2026) and its key parameters (food weight ~37%, 358 items, HCES 2023-24 source, COICOP 2018) are covered in the CPI section above. The policy-analytical dimension for Mains:

Why the weight revision matters for monetary policy: The old 2012 base placed food at ~46% of the basket. With the new 2024 base at ~37%, the same vegetable price shock — say a 30% onion spike — would add ~1.4 percentage points to headline CPI under the new weights versus ~1.7 pp under the old weights. The practical effect: the MPC's 6% failure threshold becomes harder to breach under the new series, creating more room for accommodative policy during supply-side food shocks. This is not arbitrary — it reflects that India's consumption basket genuinely shifted (urbanisation, rising incomes shift spending toward services, not staples) — but it also means the inflation target effectively tightened in real consumption terms.

The dual-series transition — resolved (March 2026): From February 2026, MoSPI publishes both series. The Government of India on 25 March 2026 formally notified the RBI to maintain the 4% ± 2% CPI inflation target for the next five-year period (1 April 2026 to 31 March 2031), confirming that the new CPI 2024 series will NOT reset the target numerically — the 4% target and ±2% band apply to the new-series CPI. As RBI Governor Sanjay Malhotra clarified (February 23, 2026), the base-year change does not warrant revision of the target itself; the MPC will use the new series for all projections from April 2026. The mechanical effect: because the new series has lower food weight (~37% vs ~46%), the same food price shock will translate into a lower CPI reading — giving the MPC modestly more headroom before breaching the 6% upper tolerance band.

UPSC angle (Prelims 2027 / Mains 2026): The dual-series transition, the policy-rate implications of lower food weight, and the governance question (which series governs the RBI's FITT mandate) are strong Mains GS3 analytical points. The base-year revision cycle (every 10–12 years) and HCES as the methodology driver are Prelims-testable facts.

IIP Growth — Manufacturing PMI Above 55, Eight Core Industries Mixed

India's IIP growth for FY 2024-25 was approximately 4% (compared to 5.8% in FY 2023-24), reflecting a slowdown in capital goods production in H1 and recovery in H2. India's Manufacturing PMI averaged above 57 in several months — among the highest globally — driven by new orders, production expansion, and input cost control. Services PMI remained above 60 in multiple months, indicating strong expansion in the tertiary sector.

Among the Eight Core Industries (constituting 40.27% of IIP), coal production grew strongly (+8.9%); electricity generation was robust; but crude oil production declined (-2.6%) due to ageing oilfields; and refinery products showed modest growth. Cement and steel production tracked infrastructure capex closely, growing in line with government construction activity.

UPSC angle: IIP growth (~4% FY25), the strong PMI readings (above 55-57), and the specific core industry trends (coal +, crude oil -) are data points tested in both Prelims (current year IIP growth) and Mains (structural manufacturing vs services debate).

Exam Strategy

For Prelims: Know CPI food weight (~37% under new 2024 base; ~46% under old 2012 base), WPI manufactured weight (64.23%), inflation target (4% ± 2%), MPC composition (6 members — 3 RBI + 3 external), RBI Act sections (45ZA, 45ZB), and current mandate period (1 April 2026 – 31 March 2031). New CPI 2024=100 base released 12 February 2026 (replacing old 2012=100 series). SDR valuation basket unrelated to inflation — don't confuse with CPI basket.

For Mains (GS3): Common question formats — evaluate India's inflation targeting framework; analyse causes of food inflation and structural reforms needed; distinguish CPI vs WPI trends and their policy implications. Key arguments: FIT improved RBI credibility and anchored expectations; food inflation requires supply-side, not just monetary, solutions; core vs headline distinction important for nuanced monetary policy.

Key Data Points:

• CPI food & beverages weight: 45.86% (old 2012=100 series) / ~37% (new 2024=100 series, effective 12 Feb 2026)
• WPI manufactured products weight: 64.23% (base 2011-12=100)
• Inflation target: 4% ± 2% (mandate renewed to 31 March 2031)
• MPC: 6 members; repo rate cut to 5.25% (125 bps cumulatively — 4 cuts in 2025: Feb+Apr+Jun+Dec); held unchanged at 5.25% in April 2026; June 2026 MPC (3–5 June) widely expected to hold
• FY 2025-26 CPI full-year average: ~2.1% (actual; Apr–Dec 2025 averaged ~1.7%; Apr 2026 reading: 3.48%)
• Food inflation: turned negative in December 2025 (–2.71%); recovered to +4.20% by April 2026 (provisional)
• WPI April 2026: 8.3% (provisional; fuel & power +24.71%; PIB/Office of Economic Adviser, May 2026) — sharp WPI-CPI divergence driven by fuel price spike

Key Terms

Stagflation

• Definition: Stagflation is an economic condition in which stagnant growth (sluggish output and rising unemployment) occurs simultaneously with persistently high inflation — a combination that classical Keynesian theory considered improbable. The word is a portmanteau of "stagnation" and "inflation".
• Context: The term was coined by British Conservative politician Iain Macleod in the House of Commons on 17 November 1965, when he warned of "the worst of both worlds — not just inflation on the one side or stagnation on the other, but both of them together." The classic episode was the 1970s, when the 1973-74 OPEC oil embargo (which roughly quadrupled crude prices) and the 1979 oil shock drove costs up across economies while output stalled. The phenomenon challenged the original Phillips curve, which assumed inflation and unemployment moved in opposite directions, and reshaped macroeconomic policy thinking thereafter.
• UPSC Relevance: Stagflation is a foundational GS3 concept under the economic-development sub-theme of inflation, growth and monetary policy, and it underpins questions on the inflation-unemployment trade-off, supply-side shocks, and the limits of conventional fiscal/monetary tools. In Prelims it is tested as a definitional/factual item (recognising the simultaneous occurrence of high inflation and low growth, and its link to the Phillips curve). In Mains (GS3) it appears within broader analytical questions on managing inflation amid global commodity shocks, the RBI's policy dilemma, and the cost-push versus demand-pull distinction. No direct PYQ exists for this exact term, but it is an enabling concept for the recurring inflation/monetary-policy question family.

Phillips Curve

• Definition: The Phillips Curve is an economic concept showing an inverse (trade-off) relationship between the rate of unemployment and the rate of inflation in an economy: when unemployment falls, inflation tends to rise, and vice versa. It was first described by economist A.W. Phillips in 1958 based on UK wage-and-unemployment data for 1861-1957.
• Context: Alban William Phillips, a New Zealand-born British economist at the London School of Economics, published "The Relationship between Unemployment and the Rate of Change of Money Wages in the United Kingdom, 1861-1957" in the journal Economica in 1958, observing that wages rose faster when unemployment was low. The relationship was later reframed in terms of price inflation and became a cornerstone of post-war Keynesian demand management, suggesting policymakers could "buy" lower unemployment by tolerating higher inflation. However, the simultaneous high inflation and high unemployment ("stagflation") of the 1970s, triggered partly by the 1973 and 1979 oil shocks, exposed the limits of the original curve. Milton Friedman (in his December 1967 American Economic Association presidential address, published May 1968) and Edmund Phelps independently argued the trade-off holds only in the short run, giving rise to the expectations-augmented Phillips Curve.
• UPSC Relevance: This is a foundational macroeconomics concept that underpins UPSC questions on inflation, unemployment, monetary policy, and the inflation-growth trade-off in GS Paper 3 (Indian Economy). In Prelims it can appear as a conceptual question on what the curve depicts or its short-run versus long-run shape; in Mains it supports analytical answers on RBI's flexible inflation targeting framework, NAIRU, and policy dilemmas in managing inflation alongside employment. It is also directly part of the UPSC Economics optional syllabus (macroeconomics). No specific verified GS PYQ is cited here; treat it as a foundational concept that strengthens answers across the inflation-monetary-policy topic family.

Base Effect (Inflation)

• Definition: The base effect is the statistical distortion in a year-on-year inflation rate caused by an unusually high or low price level in the corresponding period a year earlier (the "base"), which can make current inflation appear higher or lower than the actual change in prices warrants.
• Context: Because India's headline inflation is reported as a year-on-year percentage change in the Consumer Price Index (CPI), every monthly print is a comparison against the same month of the previous year. When that base month had abnormally low prices, even a modest price rise shows up as high inflation; when the base was abnormally high, even rising prices can show up as low inflation. The base effect is purely arithmetic — it reflects the reference point, not fresh demand-supply pressures — and it tends to unwind on its own as the unusual base month rolls out of the 12-month window. The RBI's Monetary Policy Committee routinely strips out base effects when judging the underlying inflation trend.
• UPSC Relevance: This is a foundational concept that underpins UPSC questions on inflation measurement, the CPI/WPI indices, and monetary policy under flexible inflation targeting. In Prelims it appears in factual/conceptual form (e.g., why a rapid change in the inflation rate may be attributed to the base of the previous period), so aspirants must distinguish the base effect from genuine demand-pull or cost-push inflation. In Mains GS3, it strengthens answers on inflation dynamics, RBI rate decisions and the limits of headline-print interpretation — showing examiners that the candidate reads inflation data critically rather than at face value. No verified PYQ exists for this exact term; treat it as an analytical tool for the broader inflation and monetary-policy topic family.

Buffer Stock

• Definition: A buffer stock is a reserve of an essential commodity — in India chiefly foodgrains (wheat and rice) held in the Central Pool by the Food Corporation of India (FCI) — that the government builds up through procurement at the Minimum Support Price (MSP) and releases in the open market to stabilise prices, meet welfare-scheme demand, and provide a cushion against shortages or emergencies.
• Context: In India the food buffer stock is managed by the FCI (set up in 1965) on behalf of the Government, with minimum stocking norms ("buffer norms") fixed by the Cabinet Committee on Economic Affairs on a quarterly basis — as on 1 April, 1 July, 1 October and 1 January each year. The norms comprise an operational stock (to meet monthly distribution under the Targeted Public Distribution System and other welfare schemes, including obligations under the National Food Security Act, 2013) plus a strategic reserve of 30 lakh tonnes of wheat and 20 lakh tonnes of rice. Beyond foodgrains, the government runs a separate Price Stabilisation Fund (PSF, set up 2014-15, under the Department of Consumer Affairs) to hold buffers of pulses, onion, tomato and potato, procured mainly through NAFED and NCCF.
• UPSC Relevance: Buffer stock is a high-frequency GS3 theme under agriculture, food security and the economics of the PDS, and it sits at the intersection of MSP, procurement, the FCI's finances and the NFSA. Prelims commonly tests factual recall — who fixes the norms (CCEA), the agency (FCI), the quarterly review dates, and which body runs the PSF — while Mains demands analysis of the trilemma the buffer policy tries to balance: remunerative prices for farmers, affordable food for consumers, and market price stability, alongside criticisms of excess stocks, carrying/storage costs and skewed procurement. This is a foundational concept that underpins questions on food security, the PDS, MSP reform and FCI restructuring.

Wholesale Price Index (WPI)

• Definition: The Wholesale Price Index (WPI) is an index that measures the average change in the wholesale (bulk/first point of sale) prices of goods traded in the Indian economy, compiled and released monthly by the Office of the Economic Adviser under the Department for Promotion of Industry and Internal Trade (DPIIT), Ministry of Commerce and Industry. It captures inflation at the producer/wholesale level and, importantly, covers only goods — not services.
• Context: India has compiled a wholesale price index since 1942, with the base year revised periodically — most recently to 2011-12 (notified 12 May 2017, replacing 2004-05). The 2011-12 series tracks 697 items across three major groups — Primary Articles, Fuel & Power, and Manufactured Products — with weights derived from gross value of output. Until 2014, the Reserve Bank of India used WPI as its headline inflation gauge, but on the recommendation of the Urjit Patel Committee (January 2014) it shifted to the Consumer Price Index (CPI) for monetary policy. In a major reform, the Government has revised the WPI base year to 2022-23 and is introducing Producer Price Indices (PPIs), with the revised WPI series and new PPIs scheduled for release on 15 June 2026.
• UPSC Relevance: WPI is a foundational economy concept that underpins recurring Prelims and Mains GS3 questions on inflation, price indices, and monetary policy. Prelims frequently tests factual recall — the compiling body (DPIIT, not RBI or NSO), the base year, the component with the highest weight (Manufactured Products), and the key distinction that WPI excludes services while CPI includes them. Mains GS3 typically frames it analytically: why the RBI moved from WPI to CPI for inflation targeting, the limitations of WPI (no services, global-commodity sensitivity), and the significance of the 2022-23 base-year revision and PPI transition. Aspirants should be careful not to confuse WPI with CPI or with the GDP deflator.

Inflation Targeting

• Definition: Inflation targeting is a monetary policy framework in which the central bank publicly commits to keeping inflation at a numerical target (in India, 4% CPI inflation) as the primary objective of policy. India follows a "flexible" version, with a tolerance band of 2%–6% around the 4% target that allows room to also support growth.
• Context: India adopted Flexible Inflation Targeting (FIT) after the Finance Act, 2016 amended the Reserve Bank of India Act, 1934, making price stability the primary objective of monetary policy, designating Consumer Price Index (CPI-Combined) inflation as the nominal anchor, and creating a six-member Monetary Policy Committee (MPC) to set the policy rate. The framework drew on the Expert Committee chaired by Urjit Patel (report January 2014), which recommended CPI as the anchor and a disinflation "glide path". The Central Government notified a 4% target with a 2%–6% band on 5 August 2016, retained it in 2021, and again retained it for 1 April 2026 to 31 March 2031.
• UPSC Relevance: Inflation Targeting is a high-yield GS3 economy theme (monetary policy, RBI, growth-inflation trade-off) and a recurring Prelims area. The 2023 Prelims question — "With reference to the Consumer Price Index (CPI) in India, consider the following statements..." — tests the CPI-Combined as the anchor of inflation targeting, so aspirants must know which index the MPC targets. For Mains, frame the FIT framework around the statutory basis (RBI Act sections 45ZA setting the target and 45ZN on failure reporting), the role of the MPC, and the debate on whether a single CPI target adequately captures growth and supply-side shocks.