What causes inflation and why does it matter?
Explain how inflation is measured, distinguish between demand-pull and cost-push inflation, and evaluate the costs of inflation for the Australian economy.
How the CPI measures inflation, the difference between demand-pull and cost-push inflation, underlying inflation, and the costs of inflation, with RBA and ABS context.
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What this dot point is asking
Price stability is one of Australia's core macroeconomic objectives, and inflation is the indicator that measures it. The Reserve Bank of Australia aims to keep inflation between 2 and 3 per cent on average over time, so understanding what causes inflation and why it matters is central to the macroeconomics unit.
Measuring inflation
Inflation is measured by the Consumer Price Index (CPI), compiled quarterly by the Australian Bureau of Statistics. The CPI tracks the price of a fixed basket of goods and services bought by a typical metropolitan household, weighted by how much households spend on each item. The inflation rate is the percentage change in the CPI.
Because the headline CPI bounces around with volatile items such as fuel and fresh food, the RBA also watches underlying (or core) inflation, which strips out the most volatile prices to reveal the persistent trend. The trimmed mean is the RBA's preferred underlying measure.
Demand-pull inflation
Demand-pull inflation occurs when aggregate demand grows faster than the economy can produce, so spending pulls prices up. In AD-AS terms, the AD curve shifts right while the economy is near capacity, so the steep part of the aggregate supply curve turns extra spending into higher prices rather than more output. Strong consumer spending, a stimulatory budget, low interest rates or a surge in exports can all drive demand-pull inflation.
Cost-push inflation
Cost-push inflation occurs when rising production costs force firms to lift prices even without strong demand. In AD-AS terms, the aggregate supply curve shifts left. Common triggers are wage rises that outpace productivity, higher imported input prices following a depreciation, and supply shocks such as a spike in oil or energy prices. Cost-push inflation is especially difficult because it raises prices while reducing output, the stagflation problem.
The costs of inflation
High and unpredictable inflation damages the economy in several ways. It erodes the purchasing power of money, hurting people on fixed incomes and savers. It creates uncertainty that discourages business investment and long-term planning. It distorts price signals, making it harder to tell genuine relative price changes from general inflation. It can trigger a wage-price spiral, where workers demand higher wages to keep up, feeding further cost-push inflation. And it worsens international competitiveness if Australian prices rise faster than those of trading partners, widening the trade deficit.
A strong response defines inflation, measures it with the CPI, diagnoses whether it is demand-pull or cost-push using the AD-AS framework, and evaluates its costs for purchasing power, investment, competitiveness and equity. This sets up monetary policy, the RBA's main tool for keeping inflation inside the target band.
Exam-style practice questions
Practice questions written in the style of TASC exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
2023 TASCWhat is inflation? Differentiate between demand-pull and cost-push inflation, using an example of each.Show worked answer →
Inflation is a sustained increase in the general price level over time, measured in Australia by the percentage change in the Consumer Price Index (CPI). It reduces the purchasing power of money.
Demand-pull inflation. Caused by aggregate demand growing faster than the economy's capacity to supply, so "too much money chases too few goods". Example: a strong consumer-spending boom or large tax cuts pushing demand beyond full-employment output, pulling prices up.
Cost-push inflation. Caused by rising costs of production that firms pass on as higher prices, shifting aggregate supply left. Example: a sharp rise in oil or energy prices, or a large rise in wages not matched by productivity, raising firms' costs and prices.
A clear answer contrasts the demand side (rising AD) with the supply side (rising costs / falling AS) and supports each with a valid example.
2023 TASC10 marks'Australia is currently experiencing the highest rate of inflation in more than 30 years.' Evaluate the costs of higher inflation on individuals and businesses.Show worked answer →
Define high inflation, then evaluate costs for each group, weighing them up (this is a 10-mark evaluate question, so judgement and structure matter).
Costs to individuals:
- Falling real incomes and purchasing power, especially for those on fixed incomes or whose wages lag inflation, worsening cost-of-living pressure.
- Erosion of the real value of savings if interest rates do not keep pace.
- Bracket creep, where nominal wage rises push people into higher tax brackets.
Costs to businesses:
- Greater uncertainty makes planning, pricing and investment harder, so firms may defer investment.
- Rising input and wage costs squeeze margins; menu costs arise from frequent repricing.
- Higher interest rates used to fight inflation raise borrowing costs and can reduce demand.
Evaluation. Some effects are offsetting (borrowers gain as the real value of debt falls; some firms can pass on costs). Costs are largest when inflation is high, unexpected and uneven across prices, as in the recent episode, and they fall hardest on low-income earners. Conclude that on balance high inflation imposes significant net costs, which is why the RBA targets 2 to 3 per cent.