10  Inflation

10.1 What is Inflation?

Inflation is a sustained rise in the general price level of goods and services in an economy over a period of time. The two key words are sustained and general. A one-off seasonal spike in onion prices is not inflation. A 6 per cent annual rise in the price of “everything” — a price index covering most of what households buy — is.

Mankiw defines inflation as “an increase in the overall level of prices in the economy” and the inflation rate as “the percentage change in some measure of the price level from the previous year” (mankiw2020?). Dwivedi defines it more sharply as “a sustained and substantial increase in the general level of prices accompanied by a fall in the value of money” (dwivedi2015?).

When prices rise, the purchasing power of money falls. ₹100 today buys less than ₹100 bought a year ago. Inflation and the value of money move in opposite directions — they are two ways of saying the same thing.

TipThree Working Definitions
Author / source Definition What it foregrounds
Crowther “A state in which the value of money is falling, i.e., prices are rising.” Falling money value
Pigou “Inflation exists when money income is expanding more than in proportion to increase in earning activity.” Money income
Friedman “Always and everywhere a monetary phenomenon — too much money chasing too few goods.” Monetary cause

10.2 Types of Inflation

10.2.1 By rate of price rise

TipInflation by Severity
Type Typical rate Character Example
Creeping < 3 per cent annually Mild, often considered desirable Most developed economies
Walking 3–10 per cent Warning signal Many emerging economies
Running / Galloping 10–100 per cent Serious; erodes savings India in the late 1970s
Hyperinflation Above 50 per cent per month (Cagan) Catastrophic; money loses meaning Weimar Germany 1923; Zimbabwe 2008; Venezuela 2018

The hyperinflation threshold of 50 per cent per month is from Phillip Cagan’s 1956 paper (cagan1956?).

10.2.2 By cause

TipInflation by Cause
Type Trigger Mechanism
Demand-pull Aggregate demand exceeds aggregate supply “Too much money chasing too few goods” — Keynes; Friedman
Cost-push Costs of production rise (wages, raw materials, energy) Firms pass higher costs into prices
Structural Bottlenecks, supply rigidities in developing economies Sectoral mismatch — agriculture cannot keep up
Imported Higher prices of imported goods (oil, gold) Currency depreciation amplifies the effect
Built-in / wage-price spiral Workers demand higher wages because prices rose; firms raise prices because wages rose Self-reinforcing

10.2.3 By government response

  • Open inflation — prices are allowed to rise; the government does not intervene.
  • Suppressed inflation — price controls and rationing keep measured prices stable, but shortages and black markets emerge.
  • Stagflation — inflation and high unemployment / stagnant growth occur together. The 1970s OPEC shock is the classic case.

10.3 Demand-Pull Inflation

Aggregate demand outruns aggregate supply at full employment. The standard sources:

  • Government deficit financing — printing money to fund expenditure.
  • Easy monetary policy — low interest rates, abundant credit.
  • Rise in private investment or consumer spending.
  • Rise in exports relative to imports.

The Keynesian view sees demand-pull as the primary mechanism. Friedman’s monetarist view re-cast it: every demand-pull inflation has a monetary root because demand cannot persist without money to pay for it.

10.4 Cost-Push Inflation

Inflation triggered by an autonomous rise in the cost of production. Three streams:

  • Wage-push. Strong unions secure wage increases that exceed productivity growth.
  • Profit-push. Oligopolistic firms raise margins.
  • Supply-shock. A jump in the price of a major input — most often oil — pushes costs up across the economy.

Cost-push is harder to control with conventional monetary tools because tightening money to curb prices also slows output.

10.5 Measuring Inflation

Inflation is measured by price indices. The two that matter most in India are the Consumer Price Index (CPI) and the Wholesale Price Index (WPI).

TipCPI vs WPI in India
Feature CPI WPI
Compiled by National Statistical Office (NSO) / MoSPI Office of the Economic Adviser, Ministry of Commerce & Industry
Coverage Final retail prices paid by consumers Wholesale transactions of goods only
Includes services Yes No
Base year (current) 2012 (CPI–Combined) 2011-12
Used for RBI’s monetary policy target since 2014 Producer-side price tracking; deflator for some macro series

10.5.1 The headline measure for monetary policy

Since the Monetary Policy Framework Agreement of February 2015, the RBI’s nominal anchor is CPI Combined inflation (rbi2015?). The current target is 4 per cent ± 2 per cent — so the inflation tolerance band is 2–6 per cent. The Monetary Policy Committee (MPC), formed in 2016, sets the policy repo rate to keep CPI inflation near the target.

10.5.2 Other price indices

  • GDP deflator — covers every component of GDP; broadest measure (computed implicitly from national income data).
  • Producer Price Index (PPI) — used in the US and many countries; conceptually closer to WPI but covers services too. India is moving towards a PPI but does not yet publish it as the headline.
  • Core inflation — CPI excluding food and fuel, the most volatile components. Used to read the underlying trend.

10.6 Effects of Inflation

TipEffects of Inflation — Who Wins, Who Loses
Effect Beneficiaries Losers
On debtors and creditors Debtors — they repay in cheaper money Creditors / lenders / fixed-income earners
On producers and traders Producers — selling prices rise faster than costs in the short run Salaried employees with sticky wages
On savings Holders of real assets (gold, real estate) Holders of cash and fixed-rate financial assets
On exports and imports Imports become relatively attractive Exporters lose price competitiveness
On the economy at large Mild inflation can grease the wheels High inflation distorts decisions, encourages hoarding, hurts the poor

The poor are typically the most affected — they hold their wealth in cash, spend a high share of income on food, and cannot easily switch to inflation-linked instruments.

10.7 Phillips Curve

A.W. Phillips’s 1958 finding of an inverse relation between unemployment and the rate of change of money wages — extended to inflation — became the Phillips curve (phillips1958?). The simple form: low unemployment is associated with high inflation, and vice versa.

The 1970s stagflation broke the simple curve. Friedman and Phelps’s expectations-augmented Phillips curve introduced expected inflation and the natural rate of unemployment; in the long run, the curve is vertical at the natural rate, and there is no permanent trade-off (friedman1968?).

10.8 Control of Inflation

Three families of measures:

TipThree Tool Families
Family Instrument Tightening tool
Monetary Repo rate, CRR, SLR, OMO, MSF Raise repo and CRR; sell government securities
Fiscal Tax, expenditure, public borrowing Raise taxes; cut public spending; reduce deficit
Direct / Administrative Price controls, rationing, subsidy targeting, anti-hoarding laws, wage controls Cap or freeze prices of essentials

The 1991 reforms shifted India away from heavy direct controls toward indirect monetary and fiscal levers. Since 2015, monetary policy is the lead instrument, anchored on CPI inflation.

10.9 Practice Questions

Q 01 Definition Easy

Inflation is best described as:

  • AA one-time rise in the price of essential goods
  • BA sustained rise in the general price level
  • CAn increase in the money supply
  • DA fall in real GDP
View solution
Correct Option: B
Two key words: sustained and general. A money-supply increase may cause inflation but is not the same thing.
Q 02 Friedman Easy

"Inflation is always and everywhere a monetary phenomenon." This view is most strongly associated with:

  • AJohn Maynard Keynes
  • BMilton Friedman
  • CAlfred Marshall
  • DA.W. Phillips
View solution
Correct Option: B
Milton Friedman's monetarist position — every sustained inflation has, at its root, growth of money supply faster than growth of output.
Q 03 Hyperinflation Medium

Phillip Cagan's classical threshold for hyperinflation is:

  • A10 per cent per year
  • B100 per cent per year
  • C50 per cent per month
  • D10 per cent per month
View solution
Correct Option: C
Cagan (1956) defined hyperinflation as an inflation rate of 50 per cent per month or more.
Q 04 Stagflation Easy

Stagflation refers to the simultaneous occurrence of:

  • AInflation and stagnant / falling output
  • BInflation and rising output
  • CDeflation and rising output
  • DHyperinflation
View solution
Correct Option: A
Stagflation = high inflation + stagnant growth and high unemployment. The 1970s oil-shock years are the textbook case.
Q 05 CPI Medium

RBI's monetary policy target since 2015 is anchored on:

  • AWPI inflation
  • BCPI Combined inflation
  • CGDP deflator
  • DProducer Price Index
View solution
Correct Option: B
Under the 2015 Monetary Policy Framework Agreement, RBI targets CPI Combined at 4 ± 2 per cent — a band of 2 to 6 per cent.
Q 06 Effects Medium

Inflation tends to benefit:

  • ALenders
  • BPensioners on a fixed nominal income
  • CBorrowers
  • DHolders of cash
View solution
Correct Option: C
Borrowers repay in cheaper money; lenders receive principal whose real value has fallen. Cash holders and fixed-income earners are the typical losers.
Q 07 Phillips Curve Medium

The original Phillips curve (1958) describes the relationship between:

  • AInflation and the money supply
  • BInflation and unemployment
  • CInflation and the interest rate
  • DInflation and the exchange rate
View solution
Correct Option: B
A.W. Phillips found a short-run inverse relationship between inflation and unemployment. Friedman and Phelps later argued the long-run curve is vertical at the natural rate.
Q 08 Control Medium

To curb demand-pull inflation, the RBI is most likely to:

  • ACut the repo rate
  • BRaise the repo rate and CRR
  • CBuy government securities in the open market
  • DReduce statutory reserves
View solution
Correct Option: B
Tightening = raise repo and CRR, sell securities (OMO sale). Cutting rates and buying securities are easing, which would worsen demand-pull inflation.
ImportantQuick recall
  • Inflation = sustained, general rise in the price level. Money’s value falls.
  • By rate: creeping (<3%), walking (3–10%), running/galloping (10–100%), hyperinflation (>50%/month — Cagan).
  • By cause: demand-pull, cost-push, structural, imported, built-in. Special case: stagflation (inflation + stagnation).
  • Friedman: inflation is “always and everywhere a monetary phenomenon”.
  • India: CPI Combined is the policy anchor; target 4 ± 2 per cent since 2015. WPI compiled by Office of Economic Adviser.
  • Effects: borrowers gain, lenders lose; cash holders and fixed-income earners hit hardest; the poor disproportionately so.
  • Phillips curve: short-run inflation-unemployment trade-off; long run vertical at the natural rate (Friedman–Phelps).
  • Control: monetary (repo, CRR, OMO), fiscal (tax, expenditure), direct (price control, rationing).