2018 census: what happened?

The 2018 census had the lowest response in more than 50 years – now a team is looking to find out why.

Statistics NZ had urged Kiwis to complete their census online in 2018, however one in 10 people didn’t respond, a drop of 5 per cent from the last census.

Statistics Minister James Shaw was concerned about the low response and an independent review will be conducted by New Zealand management consultant Murray Jack and Canadian census expert Connie Graziadei, Stats NZ said on Wednesday.

The government agency wanted to know what caused the lower than expected participation, and a final report from the review is scheduled to be delivered by July 2019.

‘‘We want to know what worked well and what did not work well, and why,’’ government statistician Liz MacPherson said.

‘‘We need to be clear about what we should have done better . . . We know how important census information is for decision makers across New Zealand, and so it is vital that we maintain public trust and confidence in the census.

‘‘I’m determined to do that, and the independent review, as well as the external data quality panel, announced in early September, are key steps on the way,’’ she said.

The review will also consider the ‘‘design, implementation, and operation of the 2018 census, with a focus on participation in and the coverage of the census’’.

When Stats NZ was asked in July what went wrong, it did not answer the question but instead said: ‘‘We’re pleased with the online response and performance of the online system for 2018 census. Eighty-two per cent of responses received were online which surpasses our target of 70 per cent.’’

It also pointed to the review as a way to identify what needed to be improved.

Stats NZ also set up an independent panel of data and statistics experts to assess the census results. The aim was to give confidence in the results.

That panel met for the first time in late August and would ‘‘provide independent advice to the government statistician about whether the methodologies used to produce information from the 2018 Census of Population and Dwellings are based upon sound research and a strong evidence base’’.

In July, Stats NZ was still confident the 2018 census would deliver reliable data.

Despite the lower response rate, it would ‘‘produce a highquality data set by making use of reliable government data to fill in gaps’’, deputy government statistician Denise McGregor said.

That method had been used by Stats NZ to fill in census gaps since 2001. Other national statistics organisations around the world did the same, Stats NZ said.

‘‘We know how important census information is for decision makers.’’ Liz MacPherson Government statistician