Inflation Rate YoY

Inflation Rate YoY is the 12-month percent change in the Consumer Price Index. It compares a month's index level with the same month one year earlier. The Australian Bureau of Statistics covers private households in 8 capitals, about two thirds of households.

The All groups CPI is called headline inflation. Trimmed mean and Weighted median measure underlying inflation net of large temporary price moves. A rise means inflation; percent change suits most uses better than points.

Outlets are priced in the same week monthly, fuel daily: 87% of weight monthly, 9% annually, 4% quarterly. Data go live at 11:30am Canberra time on the last Wednesday after the reference month, holidays permitting.

Quarter detail arrives with March, June, September and December releases. All users get releases simultaneously, under embargo beforehand. All groups CPI, original and seasonally adjusted, plus Trimmed mean and Weighted median. It splits goods and services, tradables and non-tradables, and market items excluding volatiles. Namely fruit, vegetables and automotive fuel.

Points contributions and city detail appear, and the ABS sets no numerical target. The index avoids revision as a policy and contract anchor, except for serious error. The seasonally adjusted series is revised monthly as seasonal factors are re-estimated.

Annual change follows 11 groups on December 2024 weights, reviewed yearly.

• Housing, 21.39%: rents, new dwelling purchases excluding land, maintenance, utilities and energy.
• Food and non-alcoholic beverages, 17.40%: bread, meat, dairy, vegetables and restaurant meals.
• Recreation and culture, 13.09%: audiovisual devices, computers, books, sport, holiday travel and accommodation.
• Transport, 11.49%: new vehicles, fuel, maintenance and urban transport fares.
• Furnishings, household equipment and services, 7.90%, and Health, 6.71%: furniture, appliances, household services, medicines and medical care.
• The rest: alcohol and tobacco (6.51%), insurance and financial services (5.57%), education (4.65%), clothing and footwear (3.17%) and communication (2.12%).

In the December 2022 quarter, released January 25, 2023, All groups CPI rose 1.9% on the quarter and 7.8% on the year. That annual rate was the highest since 1990. Seasonally adjusted inflation was 1.8%, Trimmed mean 1.7% after 1.9% in the September 2022 quarter. Trimmed mean rose from 6.1% to 6.9% over the year, its highest since 2003.

Weighted median was 1.6% and 5.8% over quarter and year, confirming breadth beyond one item. Domestic holiday travel (13.3%), electricity (8.6%), international holiday travel (7.6%) and new dwelling purchases (1.7%) led the quarter. Gains spread across housing (1.9%), food (0.9%), transport (1.7%) and recreation (5.4%), while communication fell 0.5%. Perth reached 3.6% and Darwin 0.9% for the quarter.

1. Basket split: Each city's spending comes from a Household Expenditure Survey of about 8000 households. Yearly updates use household consumption spending across 87 classes.
2. Price collection: Chosen outlets and goods mirror household shopping, priced the same week each period. Recorded prices are net of subsidies, using scanner data and the web.
3. Elementary moves: Price relatives divide current by reference prices, using the geometric mean for substitutes.
4. City averaging: Movements update prior spending to current cost, summed to the All groups total. Eight cities are weighted by household counts and average weekly spending.
5. Index numbers: Current cost links to the reference period as a Laspeyres fixed-quantity basket. Monthly change uses two monthly levels; annual change uses the same month 12 months earlier.
6. Example and contributions: A bread-and-milk basket holds 10 loaves at $2.00 ($20) and 5 litres at $3.00 ($15), costing $35. At $2.20 and $3.30, $38.50 of cost lifts the index from 100.00 to 110.00. Monthly change on prior-month 108.00 is 1.9%; annual change on 105.00 a year earlier is 4.8%. A component contributes percent change times prior share: 1% on a 4% share adds 0.04 points monthly, and 10% adds 0.4 points annually. Two-decimal indexes and one-decimal percent change use rounded values. Monthly rates never sum to the annual rate: steady 1% monthly is 12.68%, not 12%.