He said the the country will be on its own with its new method and is questioning the way the new information will be gathered.
Mr Cook, who was the New Zealand government statistician from 1992 to 2000 and the United Kingdom national statistician from 2000 to 2005, has written to every MP outlining what he thinks is wrong with the new Electoral Amendment Bill and the Data and Statistics Amendment Bill.
The Bills are before the House with the Justice select committee calling for submissions by the middle of this month.
Mr Cook said the legislation proposes to remove New Zealand’s most highly trusted and widely-used source of knowledge — the regular census.
‘‘There are significant questions about the validity of the information we would then have available to make policy decisions and whether the new concepts in the electoral Bill are fit for purpose,’’ he said.
The reasons given for the change were the failures of the census in both 2018 and 2023.
The 2023 census had a 89% return while the 2018 census had a 85.8% return. The aim was 90%.
In 2018, the result was blamed on the low number of field staff distributing forms, an over-reliance on online surveys and a lack of statisticians in senior management.
In 2023, the online-first approach overlooked some households, field staff numbers were again low and disruptions from Cyclone Gabrielle hampered the census.
Other countries have not seen a sizable drop in census response rates.
Minister of Statistics Shane Reti announced last June the government was looking to make sweeping changes around the census to provide more timely and relevant data.
This would involve using more up-to-date data and publishing a monthly consumers’ price index (CPI).
Mr Cook, who was born and bred in Dunedin but now lives in Wellington, said in making the changes, New Zealand will be alone among the countries with which it usually collaborates.
‘‘No other countries will be making a radical move from their existing approaches, which continue to evolve.’’
Other countries who had gone down the administrative data route had compulsory registration systems for all people in the country which New Zealand did not have.
He said the census underpinned not only population projections and analyses about individuals, families, households and places, but also a huge array of national and local economic, social and cultural statistics. The legislative changes would put at risk many critical statistics.
‘‘We will get further behind with geospatial innovations that integrate local information relevant to the environment, housing, infrastructure investment, the climate and emergency preparedness. Measures such as Māori descent and the richness of our ethnic statistics are in doubt.’’
