41852 – Inflation: Why Prices Rise | Australian Property Network™

41852 — Inflation: Why Prices Rise

Overview

Inflation is a rise in the general level of prices, measured as the rate at which those prices change over time. A little of it is normal and, in the view of most central banks, desirable; a lot of it erodes the value of money, wages, and savings faster than people can adjust, and squeezes anyone whose income is fixed. In Australia the consumer price index (CPI) is the headline measure, the Reserve Bank of Australia (RBA) targets it, and almost every other economic variable in this series is judged against it.^1,3

This entry explains how inflation is measured, why the RBA looks past the headline figure to “underlying” inflation, what causes prices to rise, and what the Australian record since the early 1980s shows. Housing is the largest single component of the CPI basket, so the entry closes on the two housing prices most relevant to property: the cost of building a new home and rents.⁴

Scope & Boundaries

This entry covers:

What inflation is, how the CPI is constructed, and what the trimmed mean measures
The three causes of inflation the RBA distinguishes: demand-pull, cost-push, and expectations
The Australian inflation record from 1983, and the 2021–24 episode in particular
The housing components of the CPI and what they mean for property

This entry does not cover:

How the cash rate is set in response to inflation — addressed in 41851
The historical and theoretical treatment of inflation and deflation — addressed in 41823
Wages and whether they keep pace with prices — addressed in 41854

Scope Note

This entry is educational background within an editorial essay series. Its charts use the Australian Bureau of Statistics consumer price index and the Reserve Bank of Australia’s published explainers, cited in full at the end of the page. APN’s own certified reading of Australian inflation conditions is maintained separately at node 21220.

Key Concepts

Measuring inflation: the CPI basket

The RBA’s definition is direct: inflation “is an increase in the level of prices of the goods and services that households buy. It is measured as the rate of change of those prices.”¹ The Australian Bureau of Statistics (ABS) does the measuring. It prices a basket of thousands of items, grouped into 87 expenditure classes and 11 groups, and weights each by its share of household spending, with the weights updated every year.^1,4 Housing is the largest group, and within it the two biggest items are the purchase price of new dwellings by owner-occupiers and rents. The CPI is published quarterly, with a monthly indicator alongside it, and the figure usually quoted is the change over the past twelve months.

Underlying inflation: the trimmed mean

Any quarter’s CPI includes price moves that say nothing about the economy’s underlying momentum: a cyclone that lifts fruit prices, a tax change, an energy rebate. To see through these the ABS publishes a trimmed mean, which the RBA describes as “the weighted average of the middle 70 per cent of items” after the largest rises and falls are removed.¹ It is the measure the RBA weights most heavily in deciding policy, and the measure this series uses whenever “inflation” is compared with interest rates or wages.

Chart 1

Trimmed-mean inflation, annual change, 1983 Q1 to 2026 Q2, with the 2 to 3 per cent target band (per cent)

Source: ABS Consumer Price Index, trimmed mean, seasonally adjusted, annual percentage change. The band marks the RBA’s inflation target of 2 to 3 per cent.

The record since 1983

The trimmed mean opens the series at 10.6 per cent in the March quarter of 1983 and averaged 7.5 per cent across 1983–90. The early-1990s recession broke that: inflation fell to about 2 per cent by 1992 and, once the RBA adopted its target, averaged 2.6 per cent across 1993–2007, with the mining-boom peak of 4.8 per cent in 2008 the only sustained excursion. The 2010s went the other way: inflation averaged 1.6 per cent over 2016–20 and bottomed at 1.1 per cent in the March quarter of 2021, below the band for long enough that the RBA was easing, not tightening. The pandemic reopening, supply disruptions, and the energy shock of 2022 then produced the fastest rise since the 1980s, with the trimmed mean reaching 6.8 per cent in the December quarter of 2022. It took until 2025 to return to the band, and by the June quarter of 2026 it was 3.7 per cent, above the band again: fifteen of the twenty-two quarters since the start of 2021 have printed above 3 per cent.⁴

Chart 2

Headline CPI and trimmed-mean inflation, annual change, 2012 Q1 to 2026 Q2 (per cent)

Source: ABS Consumer Price Index. Headline is the all-groups CPI; trimmed mean is seasonally adjusted. Headline inflation is more volatile because it includes the items the trimmed mean removes.

Headline versus underlying

Chart 2 shows why the distinction matters. Headline CPI fell to minus 0.3 per cent in the June quarter of 2020, when free childcare and sharply lower fuel prices pulled it briefly negative, while the trimmed mean stayed positive. Headline peaked higher in 2022, at 7.9 per cent, and fell faster in 2024–25 as electricity rebates cut measured power bills; by the June quarter of 2026 headline was 3.9 per cent against a trimmed mean of 3.7 per cent. A household pays headline prices, so headline is the right measure of the cost of living. The RBA sets policy on the trimmed mean because it is the better guide to where headline will be in a year’s time.^1,3 Over the whole period the difference washes out: the headline CPI level is 49.8 per cent higher in the June quarter of 2026 than in the March quarter of 2011, and the trimmed-mean index is 25.4 per cent higher than at the end of 2019.

What causes inflation

The RBA distinguishes three sources.² Demand-pull inflation “arises when the total demand for goods and services increases to exceed the supply of goods and services that can be sustainably produced”: too much spending chasing a fixed capacity, the classic case for higher interest rates. Cost-push inflation “occurs when the total supply of goods and services in the economy which can be produced falls”: a supply shock such as an oil price rise or a shipping disruption raises costs, and firms pass them on. Inflation expectations “are the beliefs that households and firms have about future price increases”; if workers and businesses expect 5 per cent inflation they bargain and price for it, and the expectation becomes self-fulfilling. The 2021–23 episode contained all three, which is why it was both larger and slower to unwind than a pure demand or supply shock would have been.

Chart 3

Housing components of the CPI: new dwelling purchase by owner-occupiers and rents, annual change, monthly, September 2018 to July 2026 (per cent)

Source: ABS Consumer Price Index, Table 3, monthly series for new dwelling purchase by owner-occupiers and rents; annual change. The rents series is published from July 2022, so its annual change begins in July 2023.

Inflation and housing

The housing group is where inflation and property meet. New dwelling purchase measures the cost of building a new home excluding land, and it recorded the sharpest rise of any major CPI component in the recent episode: an annual increase of 21.7 per cent in July 2022, as materials and labour shortages hit the construction sector. By July 2026 it was running at 5.7 per cent, still above the rate of the CPI as a whole. Rents lag: they reprice only when leases turn over, so rent inflation peaked later, at 7.8 per cent in August 2023, and by July 2026 had eased to 3.6 per cent.⁴ Both feed back into the wider economy: construction costs set the price at which new supply can be delivered, and rents are the single largest expense for the third of households who do not own their home.

Regulatory & Legal Framework

The CPI is compiled by the ABS under its own statistical legislation and published on a fixed calendar; the quarterly release is the reference for indexation of pensions, rents under many leases, and contract escalation clauses across the economy.⁴ The ABS also publishes Selected Living Cost Indexes for different household types, which include mortgage interest charges that the CPI excludes and are therefore a better guide to the cost pressure on a mortgaged household when rates rise.⁵

The inflation target is an agreement, not a statute. The Statement on the Conduct of Monetary Policy between the Treasurer and the RBA records the objective of keeping consumer price inflation between 2 and 3 per cent, with policy set so that inflation is expected to return to the midpoint, 2.5 per cent.^3,6 The band is deliberately a range rather than a point, and it is assessed over time rather than quarter by quarter, so a single reading outside it does not require a response; a sustained run outside it, as in 2021–24, does. Because monetary policy takes one to two years to have its full effect, the RBA responds to where it expects inflation to be, not to the latest print.⁷

Practical Application

Real values. Every figure in property is a nominal figure until it is deflated. A house that sold for $500,000 in early 2011 and $750,000 in mid-2026 rose 50 per cent in dollars but roughly nothing in purchasing power, because the CPI rose 49.8 per cent over the same period. Long-run price comparisons that ignore this overstate real gains, and rental yields quoted against a rising price level overstate real returns.

Rents and leases. Rent inflation runs behind CPI inflation on the way up and on the way down, because leases reprice at renewal. A landlord reading the CPI in 2022 saw 7 per cent inflation while rent reviews were still delivering 2 to 3 per cent; by 2024 the positions had reversed. Indexation clauses tied to the CPI transmit headline inflation into commercial leases with a lag of one quarter.

Construction costs. The new dwelling purchase component is the closest thing in the CPI to a build-cost index. Its 2021–23 surge is why fixed-price building contracts signed in 2021 became loss-making, why several builders failed, and why the cost of delivering new supply reset roughly a quarter higher than before the pandemic. Anyone comparing the price of an established home with the cost of building a new one should start from this series rather than from the general CPI.

Interest rates. Because the RBA targets inflation, the trimmed mean is the best single predictor of where the cash rate is heading. A reading above 3 per cent with the labour market tight, as in mid-2026, is the configuration in which rates rise; a reading below 2 per cent, as in 2019–20, is the configuration in which they fall. The mechanics are addressed in 41851.

Cross-Series References

41851

Interest Rates: The Price of Money

How the cash rate is set in response to inflation, and why the real rate is what matters.

41854

Wages and Real Incomes

Whether pay has kept up with these prices since 1998, and where it stands now.

41823

Inflation and Deflation

The longer history of rising and falling prices, and the damage each does.

21220

Inflation

APN’s live certified reading of Australian inflation against its long-run baseline.

Sources

1. Inflation and its Measurement — Reserve Bank of Australia, Explainer
2. Causes of Inflation — Reserve Bank of Australia, Explainer
3. Australia’s Inflation Target — Reserve Bank of Australia, Explainer
4. Consumer Price Index, Australia — Australian Bureau of Statistics
5. Selected Living Cost Indexes, Australia — Australian Bureau of Statistics
6. Monetary Policy Framework, including the Statement on the Conduct of Monetary Policy — Reserve Bank of Australia
7. The Transmission of Monetary Policy — Reserve Bank of Australia, Explainer

This entry is part of the Understanding Money editorial essay series and is presented for general educational context. APN’s certified reading of current Australian inflation conditions is maintained at node 21220, Inflation.

41852 – Inflation: Why Prices Rise