The day the paper-based Census died
On 18 June 2025, Statistics New Zealand announced the death of the paper-based Census. No more will Statistics New Zealand ask everyone living in Aotearoa New Zealand to fill out a paper or online Census form every five years.
Instead, Statistics New Zealand will begin a new approach to understanding our population with an annual Census using administrative data already collected by government agencies.
According to the Government Statistician:
This is an exciting and necessary change. The traditional way of running a nationwide survey on census day can no longer be justified, due to rising costs, declining survey response rates, and disruption from events, like Cyclone Gabrielle in 2023.
Cost is a primary motivator of this decision for the Government, with Minister of Statistics, Shane Reti saying, “The move reflects the need for more timely and cost-effective insights”, pointing to the $325 million cost of the 2023 census and an expected $400 million for the next. A secondary driver is the declining rate of response and the greater use of administrative data to fill in the gaps from this declining response. Moving to an admin-based Census provides the benefit of an annual Census rather than the current five-year cycle, without the risk of a further decline in response rates.
From a funding perspective, spending $400 million over five years is arguably justified. Census data underpins decisions on allocating billions of dollars in central and local government spending. High-quality data ensures that resources are directed efficiently and equitably. Although the counterargument is that an annual admin-based Census should be much cheaper and, while of lesser quality, can still provide sufficient quality of data for these decisions. One hopes that this trade-off has been rigorously assessed by Statistics New Zealand.
The implications extend beyond government budgets. Decisions based on less accurate and granular data have the potential to be less well targeted, which is seemingly at odds with the current Government’s policy of ensuring effective and efficient spending. Statistics New Zealand revealed on 28 June that:
Scrapping the Census will see expected permanent and temporary drops in “quality, accuracy, and coverage” of some Māori data. In addition, there are areas where improvements to administrative data would need to be made, and “initially there will be a reduction in the quality, accuracy, and coverage for some topics and smaller population groups”
Hence, compared to the 2023 Census, there will be both permanent and temporary reductions in the data granularity and quality of the new annual admin-based Census in 2030.
To limit the loss of data and data quality Statistics New Zealand has five years to identify where data, which can only be gathered from Census surveys, can be sourced from, and to improve the data collection methods and data quality of other central government agencies (upon which the new admin-based Census will be reliant).
The need to find other data sources, or ways to fill the data gaps left by the removal of the Census, is due to the Privacy Act 2020, which dictates that government agencies can only collect the minimum amount of data from individuals that is required for them to properly undertake their functions and mandates. This limits the ability of Statistics New Zealand to organise other government agencies to collect additional data from individuals.
So far Statistics New Zealand has suggested running a small annual sample survey to fill in data gaps that cannot be collected from other agencies’ administrative datasets. While a sample survey would be sufficient at a national level, it would not provide granular data. For instance, Statistics New Zealand’s current largest sample survey, the Household Labour Force Survey, can provide national-level data on employment variables but only provides limited data breakdowns below the national level.
It is highly detailed granular data that made the Census dataset valuable to New Zealand. It allowed the analysis of small population segments, whether ethnic groups, country groups, sexual orientation groups, or even small towns and areas of the country.
The decision to modernise the Census may have merit. But it also demands vigilance. As Statistics New Zealand moves forward, it must ensure that the new system maintains the integrity, inclusiveness, and utility of the data it replaces. We may otherwise miss the current Census more than we realise.