Inflation at 4% leaves the RBA with no comfortable option
Australia's headline inflation reached 4% in the year to August, up from 3.5%. The reading, reported on 30 September, puts price growth further above the Reserve Bank's 2% to 3% target band and sharpens the policy bind in Canberra. The Guardian
Petrol did most of the damage. Fuel prices surged 15% in the month, according to the Australian Bureau of Statistics, and the Bureau confirmed rising transport costs were the prime contributor to the monthly increase.
Petrol, housing and power drive the monthly read
The detail was not confined to the bowser. Home building costs rose 5.4% over the 12 months to August as builders passed on higher materials and labour costs, the ABS said. Electricity bills were higher than a year earlier, when households were still receiving government rebates. That base effect matters. So does fiscal timing: the government ended its cut to fuel excise, adding a direct administrative lift to pump prices.
Underlying inflation was steady at 3.6% in the year to August. The gap between headline at 4% and underlying at 3.6% tells its own story. Volatiles and regulated prices are doing the work at the top line. In original terms, the Consumer Price Index rose 0.4% for the month of August. ABS
For data watchers, there is plumbing to note. The Bureau states its Monthly Consumer Price Index Indicator release has ceased, with September 2025 listed as the latest release of that series. The monthly read now sits inside the quarterly CPI apparatus, not as a standalone indicator.
The Bank moves, and markets were ready
The Reserve Bank has lifted its cash rate to 4.6%, the fourth increase in 2026. The Guardian
The sequence matters for anyone pricing the Board's reaction function. As of 19 August, the Bank had held steady at 4.35%. By August it had already added 75 basis points since February, and it debated a hike at its August meeting. Reuters
The September meeting was scheduled for 28-29 September. On 18 September, markets implied a 93% chance the Bank would lift to 4.6% at that meeting. Reuters
Forward guidance has been blunt. In August the Bank forecast inflation would move back to the 2% to 3% band in the second half of 2027. In its August Statement on Monetary Policy, it said inflation was still too high and was not expected to return to the middle of the 2-3 per cent target range until early next year.
EY chief economist Cherelle Murphy said another hike looks likely by the end of the year. On current arithmetic, that would be a fifth increase in 2026.
Canberra's line and what comes next
Treasurer Jim Chalmers said headline inflation was expected to rise because global oil prices were flowing through to petrol prices in Australia. He made the point in a 28 September interview. Treasury
It is consistent with his earlier framing. Chalmers has said upward pressure on inflation in July around the world was due to movements in the global oil price. In the 2026-27 Budget speech, Treasury presented a more severe scenario where the oil price peaks at $200 and takes three years to fall back down.
Housing is moving the other way. House prices fell 2.7% nationally by August from their March 2026 peak. That tightening in asset values sits alongside building-cost inflation in new construction. One is the price of the existing stock. The other is the cost of adding to it.
The broader context here is the collision fiscal and monetary types always dread. Headline is accelerating on fuel and administered unwinds. Underlying is stuck. Construction costs are re-accelerating. The excise and rebates decisions were defensible on budget repair grounds. They still add to the CPI prints the Board must respond to.
In my view, Chalmers' oil-price explanation is accurate and incomplete. Accurate, because 15% monthly fuel growth dominates the arithmetic and global crude is the marginal setter. Incomplete, because Canberra controls the excise lever and the rebate profile, and both flattered the base then lifted the current read. The government says external factors; the figures include domestic policy pass-through as well.
Looking at what this means for the next Board decision, the test is persistence. A fuel spike alone can be looked through. A fuel spike combined with 3.6% underlying, 5.4% annual new-dwelling cost growth and market pricing already conditioned for tightening is harder to dismiss. That is why Murphy's call for another move before Christmas will get a hearing in Martin Place and in the press gallery. Borrowers will hear it differently. Four hikes this year, with a fifth in prospect, is tightening that bites with a lag. The politics will too.
