Inflation (CPI and WPI)

Inflation is a sustained rise in the general price level of goods and services in an economy over time, which reduces the purchasing power of money — each rupee buys a little less than before. A moderate, stable level of inflation is considered healthy for growth, but very high or very volatile inflation hurts savers, fixed-income earners and the poor the most. Measuring and controlling inflation is therefore central to economic policy, and it is one of the most heavily tested areas of the UPSC Economy syllabus.

How inflation is measured

India measures inflation mainly through two price indices. The Consumer Price Index (CPI) tracks the retail prices of a basket of goods and services actually bought by households, and is compiled by the National Statistical Office (NSO). The Wholesale Price Index (WPI) tracks prices of goods traded at the wholesale level and is compiled by the Office of the Economic Adviser. A third measure, the GDP deflator, captures price changes across the entire economy. The inflation rate is usually expressed as the year-on-year percentage change in the index.

CPI vs WPI — the key difference

The CPI and WPI differ in important ways. CPI includes both goods and services and reflects the prices consumers actually pay, giving a truer picture of the cost of living; food and housing have large weights in it. WPI covers only goods (not services) and reflects prices at the factory or wholesale gate, so it responds quickly to changes in fuel and commodity prices. Because CPI better reflects consumer welfare, the RBI uses CPI (Combined — rural plus urban) as the anchor for its inflation-targeting framework. The two indices can diverge sharply, which is a common exam point.

Types by cause — demand-pull and cost-push

Inflation is classified by its cause. Demand-pull inflation occurs when aggregate demand exceeds the economy's capacity to supply goods and services — 'too much money chasing too few goods'. Cost-push inflation occurs when the cost of inputs like fuel, wages or imported raw materials rises, pushing up prices even when demand is not excessive. Built-in inflation arises from a wage-price spiral, where workers demand higher wages to match rising prices, which in turn raises costs further.

Types by intensity

By intensity, economists distinguish creeping inflation (slow and mild), walking or trotting inflation (moderate), galloping inflation (very high double or triple digits) and hyperinflation (extremely rapid and out of control, as seen historically in Germany or Zimbabwe). Two special situations are important: stagflation, where high inflation coexists with stagnant growth and high unemployment, and deflation, a sustained fall in prices that can be equally damaging by depressing demand and investment.

Causes and effects in India

In India, inflation is often driven by food and fuel prices, supply-side shocks (like poor monsoons or global oil-price spikes), and at times excess demand or high government spending. Its effects are uneven: it erodes the real income of the poor and fixed-income groups, discourages saving, and can worsen inequality, while borrowers may gain and lenders lose in real terms. Persistent high inflation also raises uncertainty and can hurt long-term investment.

Controlling inflation

Inflation is tackled through both monetary and fiscal measures. The RBI uses monetary policy — chiefly raising the repo rate and tightening liquidity — to cool demand-driven inflation. The government uses fiscal and administrative measures, such as managing food stocks and the public distribution system, adjusting import-export duties, and controlling its own borrowing. Because much of India's inflation is supply-side (especially food), monetary policy alone is often not enough, making government supply-management crucial.

Why it matters for UPSC

The CPI-WPI distinction, which agency compiles each index, the RBI's use of CPI for inflation targeting, and the types of inflation (demand-pull, cost-push, stagflation, deflation) are classic Economy Prelims topics, and inflation control is a strong Mains theme linking monetary and fiscal policy.