Inflation

A-Level Economics · Macroeconomics

Inflation: Causes, Costs & Control

Inflation is a sustained increase in the general price level, measured by the CPI (target: 2% in the UK, set by the government for the Bank of England). Understanding its causes, consequences, and policy responses is central to macroeconomics.

Types of Inflation

Demand-Pull Inflation

Occurs when aggregate demand grows faster than aggregate supply, pulling prices up.

Causes:

Consumer confidence and wealth effects (rising house prices)
Expansionary fiscal policy (tax cuts, spending increases)
Expansionary monetary policy (low interest rates, QE)
Depreciation of the exchange rate (exports rise, imports cost more)
Global economic boom (rising demand for UK exports)

Diagram: AD shifts right along an upward-sloping SRAS → higher price level, higher real output (if spare capacity exists). Near full capacity, the price effect dominates.

Cost-Push Inflation

Occurs when costs of production rise, pushing up prices independently of demand.

Causes:

Rising commodity prices (oil, gas, food)
Depreciation (raises cost of imported raw materials)
Higher wages (above productivity growth)
Indirect tax increases (VAT, duties)
Supply chain disruptions (COVID-19, Suez Canal blockage)
Increased regulation/compliance costs

Diagram: SRAS shifts left → higher price level AND lower real output. This combination is called stagflation (stagnation + inflation).

Monetary Inflation

Monetarist view (Friedman): "Inflation is always and everywhere a monetary phenomenon."

Excessive growth in the money supply relative to output causes inflation
Based on the Quantity Theory of Money: MV = PQ
M = money supply, V = velocity of circulation, P = price level, Q = real output
If V and Q are constant, an increase in M leads to a proportional increase in P
Monetarists advocate controlling the money supply to control inflation

Evaluation: V is not constant (it changes with technology, confidence, financial innovation), and the money supply is difficult to define and control precisely. The relationship between money supply and prices has weakened in modern economies.

Costs of Inflation

If Anticipated

Even expected inflation has costs:

Menu costs: firms must update prices (reprinting, reprogramming)
Shoe-leather costs: people economise on cash holdings (more trips to the bank/ATM)
Fiscal drag: if tax thresholds are not index-linked, inflation pushes earners into higher brackets
Reduced international competitiveness: if UK inflation > trading partners → exports less competitive → current account deteriorates

If Unanticipated (worse)

Redistribution of income and wealth:
Borrowers gain (repay loans in money worth less) — debtors benefit
Savers lose (real value of savings erodes) — creditors suffer
Fixed-income earners (pensioners on non-indexed pensions) see purchasing power fall
Uncertainty and reduced investment: businesses cannot plan if future costs and prices are unpredictable → reduces long-term growth
Wage-price spiral: workers demand higher wages to compensate for inflation → firms raise prices to cover higher wages → further inflation
Reduced real wages if nominal wages do not keep pace

Benefits of Low, Stable Inflation

Some economists argue moderate inflation (around 2%) is beneficial:

Allows real wage adjustment (firms can freeze nominal wages rather than cut them, which workers resist — money illusion)
Provides a buffer against deflation (far more damaging)
Reduces the real burden of government and private debt over time
Encourages spending rather than hoarding money

Deflation

Deflation is a sustained fall in the general price level (negative inflation).

Types

Benign deflation: caused by increased productivity or technological improvement (supply-side) — prices fall but output rises. Example: falling electronics prices.
Malign deflation: caused by falling aggregate demand — associated with recession, unemployment, and debt deflation.

Costs of Malign Deflation

Delayed consumption: consumers wait for lower prices → AD falls further (deflationary spiral)
Rising real value of debt: borrowers' real burden increases → defaults, bankruptcies
Rising real wages: firms cannot cut nominal wages → unemployment rises
Monetary policy ineffective: interest rates cannot fall below zero (zero lower bound / liquidity trap) — Keynes described this
Expectations: once deflationary expectations set in, they are self-reinforcing

Historical example: Japan's "Lost Decade" (1990s-2000s) — prolonged deflation, stagnant growth, and ineffective monetary policy.

The Phillips Curve

Original Phillips Curve (1958)

A. W. Phillips found an inverse relationship between unemployment and wage inflation in UK data (1861-1957). This was extended to price inflation:

Low unemployment → high inflation
High unemployment → low inflation
Implies a policy trade-off: governments can choose a point on the curve

Monetarist Critique (Friedman & Phelps)

Expectations-augmented Phillips curve:

Friedman (1968) argued the trade-off is short-run only
In the long run, the Phillips curve is vertical at the Natural Rate of Unemployment (NRU) / NAIRU
Attempts to reduce unemployment below the NRU through demand management will lead to accelerating inflation as workers adjust expectations upward
The NRU is determined by supply-side factors (labour market flexibility, skills, information)

Process:

1. Government expands AD → unemployment falls below NRU

2. Inflation rises → workers demand higher wages (adaptive expectations)

3. Real wages return to previous level → unemployment returns to NRU

4. But now at a higher rate of inflation

5. To reduce unemployment again requires even more inflation (short-run Phillips curve shifts up)

Rational Expectations (New Classical)

Lucas, Sargent: if agents have rational expectations, they anticipate policy changes immediately:

Expansionary policy is fully anticipated → wages and prices adjust instantly
No short-run trade-off at all (Phillips curve is vertical even in the short run)
Only unanticipated policy has real effects

Evaluation

The Phillips curve trade-off appeared to break down in the 1970s (stagflation: high inflation AND high unemployment — oil shocks)
Post-2008: low unemployment with low inflation ("the missing inflation") — possibly due to globalisation, weak bargaining power, gig economy
The relationship may be non-linear: flat at low inflation but steepens as the economy overheats

Controlling Inflation

Policy	Mechanism	Evaluation
Monetary policy (main UK tool)	Bank of England raises Bank Rate → higher borrowing costs → lower C and I → lower AD	Effective but time lags (18-24 months); may cause unemployment; ineffective at zero lower bound
Fiscal policy	Raise taxes / cut spending → lower AD	Direct but politically difficult; time lags; may conflict with other objectives
Supply-side policies	Increase LRAS (education, deregulation, infrastructure) → reduce cost-push pressures	Long-term solution but slow to take effect; does not help with demand-pull in the short run
Exchange rate policy	Appreciation reduces import prices	Not directly controlled in floating regime; harms exporters
Wage/price controls	Direct limits on wage/price rises	Distort markets; temporary; may create shortages; historically unsuccessful (Nixon 1971)

Exam Technique

Distinguish demand-pull from cost-push — they require different policy responses
Draw the AD/AS diagram showing the inflationary shock and policy response
Use the Phillips curve to discuss the trade-off between inflation and unemployment
Evaluate the effectiveness of monetary vs fiscal vs supply-side responses
Reference current UK inflation trends and Bank of England decisions
In 25-mark essays, discuss whether inflation is always harmful (consider low stable inflation vs high/volatile inflation vs deflation)