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 (Base Year: 2012=100)

The CPI (Combined) basket uses the following group weights:

Food & beverages carry the highest weight at nearly 46%, which means food price shocks strongly influence headline CPI. This is why vegetable price spikes and poor monsoon seasons have an outsized effect on India's measured inflation.

New Base Year: The CPI series on base 2024=100 is scheduled to be released from February 2026, replacing the 2012=100 series.

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 45ZI: MPC must publish minutes within 14 days of each meeting

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: 2.6% (revised down from 3.1% earlier in the year).

RBI Rate Actions (February–April 2025): RBI reduced the repo rate by cumulative 100 basis points from February 2025, bringing the rate to 5.25%, as easing inflation created space to support economic growth. 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 — 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

Exam Strategy

For Prelims: Know CPI food weight (45.86%), 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). CPI base year being revised to 2024=100 (effective February 2026). 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%
• WPI manufactured products weight: 64.23%
• Inflation target: 4% ± 2% (mandate renewed to 31 March 2031)
• MPC: 6 members; repo rate cut to 5.25% (100 bps cumulatively from February 2025)
• FY 2025-26 CPI inflation forecast: 2.6% (RBI revised down)
• Food inflation: turned negative in December 2025 (–2.71%)