Statistics NZ details timeline for start of monthly CPI inflation data

Statistics New Zealand will start publishing monthly Consumers Price Index (CPI) inflation data from July next year.

Currently, NZ is the only OECD (Organisation for Economic Co-operation and Development) country without a monthly CPI. The CPI only being reported quarterly has long frustrated Reserve Bank policymakers seeking the most up-to-date data for their monetary policy decisions. The Reserve Bank uses the CPI as the official measure of inflation in its inflation targeting.

The move to bolster its statistics reporting comes after the data agency received a funding boost from Budget 2025 to produce more economist statistic reporting. Alongside monthly inflation data, from late 2027, Statistics NZ will provide 25 new monthly industry indicators on economic activity as well as improvements to balance of payment statistics.

Speaking to interest.co.nz, Stats NZ general manager of macroeconomics Jason Attewell said the data agency published about nearly 600 price indexes as part of the quarterly CPI right now and these would be available monthly next year. 

Stats NZ would continue to produce the CPI quarterly, Attewell said. “The quarterly CPI is not going away, but the monthly CPI will be at the same level of detail.”

From early 2027, internal production testing of the monthly process will begin. And by May, the data agency will release a transitional report covering price changes in April. 

Next June Statistics NZ will release a transitional report covering price changes in May. And from July, it will publish the first official release covering the June month and the June quarter, completing the first quarter of the monthly CPI under the new system. 

From August 2027 onwards, Statistics NZ will release ongoing monthly CPI releases. 

Asked whether he was confident about the data agency’s timeline, Attewell said while it was a lot of work, they had some strong partnerships and had the support of the Australian Bureau of Statistics, which started producing a monthly CPI in November last year. 

“We work really closely with them at all levels of governance, so that they can share their experience.”

In terms of the transitional reports in May and June, Attewell said it was about making sure their customers were ready for the changes as well. 

“We know that people will need to update their forecasting models. They’ll want to understand what the new parts of the monthly CPI look like so they they can get a feel for it.

“We’re using the word ‘transition’ deliberately to highlight that it’s about the work we have to do … all the news systems and technology but it’s also about making sure our customers are ready and we’ve done all the statistical quality assurance so that by the time we put it out, people can trust that is it good quality data,” he said.

Stats NZ said the reports would include data produced through the new monthly process, along with monthly figures for the previous year so users can compare how prices have changed over time. 

Users would be able to test how the data works with their systems, how they access it, and how to interpret and use monthly price movements, the data agency said.

Government Statistician and Statistics NZ chief executive Colin Lynch said moving from quarterly to monthly information would provide a more current view of price changes across the economy. 

He said it wasn’t simply a matter of publishing the existing CPI more often. Statistics NZ had taken a digital-first approach and was changing how price information is collected, processed, checked and published so they could produce reliable information every month.

“CPI is closely watched and widely used, so maintaining the quality of the data and the trust people place in it is fundamental to how we are making this change,” Lynch said.

“The CPI is used to inform decisions that affect all New Zealanders, from interest rates and government policy to business planning, contracts, and household finances.”

“Providing a monthly CPI from 2027 represents a major change to one of New Zealand’s most important economic measures, so it is essential this is done with quality and trust at its heart,” said Lynch.

Statistics Minister Scott Simpson said these changes mean “better-informed household, business and government decisions”.

“The transition to monthly CPI data puts quality, trust and readiness first, while giving users advance access to the information they have asked for.”