Why Stats NZ is planning to overhaul the Census

Stats NZ is looking to overhaul the census, relying more on existing "real-time" data from benefits and tax records.

At the moment the data-gathering exercise happens every five years, with the next one due in 2028.

Stats NZ said it wanted to take an admin-data-first approach, meaning it will use existing data to get Census information.

That would help it update questions in its surveys and publish statistics faster.

Stats NZ chief executive Mark Sowden told Checkpoint, for a start, it would look at data from survey forms and add in data from other sources around government.

Data older than five years reflected a time lag, he said.

"Whereas with the data that New Zealanders already give government through things like applying for a benefit or paying their taxes ... is actually real-time and up to date."

Currently Stats only has reliable data on the population and incomes.

He said it had only been a few years that that data was at the right level of quality and the right level of coverage for New Zealanders.

"We're still only just starting along this journey.

"We have good data for things like the population count and incomes. But there's a lot of things we still don't have good quality data for, and we're building that out as we go."

That's why surveys would continue, he said.

Last year's Census cost an estimated $316 million and between 89 and 91 percent of New Zealand had responded to the survey.

If held the same way in 2028, it would cost much more.

But the new method was "not really about saving money", Sowden said.

He said the current model was not sustainable.

And while the new model "may not cost less", if Stats could "collect data from the majority of New Zealanders more cheaply, we can use some of the more targeted solutions for those harder to reach groups" like the Pacific, Māori and disabled communities.

New Zealanders can have a say on the new Census proposal until 18 June.