Inflation Rate QoQ

Inflation Rate QoQ is the quarterly % change in the Consumers Price Index (CPI), the fixed basket measure published by Statistics New Zealand (Stats NZ). It tracks goods and services bought by private households, covering about 98% of usual residents in permanent dwellings. Each quarter collectors gather about 100,000 prices from over 2,800 shops in 12 centres plus online, till-scanner, web and administrative sources. Systematic measurement started in 1914 with quarterly publication in 1924, and it guides monetary policy, performance checks, superannuation, contracts and wage talks.

Prices follow fixed cycles, weekly for some fuels and fresh produce, monthly for food and groceries, and quarterly for other items. Monthly averages form quarterly averages by day weighting by days, and release falls 12 working days after quarter end at 10:45am except December holidays. Each release adds fact tables, driver commentary, graphs and data files plus analytical splits, while headline CPI stays final and errors pass to next quarter. Markets watch quarterly and annual changes for rate policy signals, with higher readings pointing to tighter expectations against the Reserve Bank 1 to 3% band.

Price pressure comes mainly from the 11 basket groups plus import and domestic splits.

• Housing and household utilities, 29.41%: captures rents, new dwelling building, rates, maintenance and household energy.
• Food, 18.45%: captures groceries, meat, fish, produce and restaurant or ready to eat meals.
• Transport, 14.34%: captures petrol, diesel, private transport goods and services and passenger transport.
• Recreation and culture: captures games, hobbies, accommodation and cultural services.
• Alcoholic beverages and tobacco, household contents and services, and health: covers alcohol and tobacco, furnishings and appliances, GP fees and prescriptions.
• Clothing and footwear, communication, education, and miscellaneous goods and services: covers clothing, footwear, telecoms, education and personal care.

The December 2022 quarter showed headline, or all items, inflation of 1.4% for the quarter and 7.2% for the year, or 1.5% with seasonal adjustment. Quarterly gains came from housing at 1.3%, food at 1.8% and recreation and culture at 3.4%, with non-tradables at 1.5% and tradables at 1.4%. Annual gains came from housing at 8.0%, food at 11% and transport at 8.4%, with non-tradables at 6.6% and tradables at 8.2%. Trimmed means, or core readings, ran 6.1% to 6.5% for the year, below the 7.2% headline, as a ferry fare error left published data unchanged.

1. Elementary averages: prices across 12 centres and 5 regions, or national figures where regional estimation is unsupported.
2. Jevons and Dutot means: geometric means apply where shoppers switch outlets, and ratios of mean prices where switching is impossible.
3. Quarterly averaging by day weighting: monthly outlet weighted averages become quarterly averages by weighting months by days. Petrol weekly prices per 10 litres average to monthly then to quarterly, so a mid quarter move splits across quarters.
4. Regional and outlet weighting: regional moves since June 2017 combine with spending weights, and observed sale prices enter directly. Auckland holds 34.75% spending weight against 33.63% population share.
5. Fixed basket Laspeyres average: upper levels use a weighted average with earlier period spending shares, with June 2017 as 1000. Weights reflect spending in the year to June 2023 at December 2024 prices, sourced from the Household Economic Survey.
6. Quarterly rate: quarterly change divides rounded index gain by prior rounded index; 1302 against 1290 gives 100 x 12 / 1290 = 0.9%.
7. Contributions from unrounded indexes: component effects use unrounded indexes, so rounded parts may not sum to headline. Rates publish to 1 decimal place.