The dud 2018 census revealed last week can damage Rotorua, writes Ian McLean, a former National Party Cabinet Minister.

In the 2018 census the collection response rate of Maori was only 68.2 per cent.

This compares with 88.5 per cent in the last census (and 93.1 per cent in 2006).

The poor result can affect Maori and Pakeha alike in Rotorua.

Funding for our hospital depends partly on how well-off-our people are. The basic data comes from the census.

With a dud census, the deprivation level of our community is a guess.

If Lakes DHB doesn't get enough money, it affects everybody who needs treatment – Pakeha as well as Maori.

The census is also used to decide how many Maori seats are in Parliament. The calculation is complicated – even with a good census result.

Unless Statistics NZ can track (for example) the ethnicity of every person who comes and goes to Australia, the '2018 census” Maori population is a guess.

The percentage population of people with Maori ancestry and living in New Zealand has risen over the years. If the increase is big enough, and enough choose the Maori roll, there will be an extra Maori seat in Parliament.

This would affect the boundaries of existing Maori seats such as

Waiariki.

But the Rotorua electorate and its boundaries will also be affected by Statistics NZ guesstimates of where people live.

Electoral rolls can help to fill the gaps in a dud census, but are always unreliable for people who move around a lot. And the Police Intelligence data base does not cover everyone.

Unless Statistics NZ keeps tabs on everyone individually with all key

government departments, the result can only be a guesstimate.

Statistics NZ needs to publish right now how it will adjust the poor 2018 census returns. The Inquiry into the census asked for this*.

And we need a new census, just as soon as possible.

In the meantime, we have to rely on the dud census.

* '…the organisation should communicate clearly the measures it has taken to ensure quality in census data as well as its limitations”. – Report of the Independent Review of New Zealand's 2018 Census.