"Pākehā says we acknowledge Māori. It says politically we're serious about treaty relations, that we're committed to biculturalism and that we've grown up here rather than somewhere else."
Hosking has started an Action Station petition to rally support.
Hosking felt strongly about identifying with the ethnicity Pākehā rather than NZ European.
"Pākehā is a Māori word, it's a New Zealand word. If you talk broadly about who you are the equivalent for people like me is Pākehā.
"I don't know anyone who calls themselves NZ European. It is just not how I feel."
Hosking, who is a human rights consultant to the United Nations, said he knew lots of people who put other unofficial ethnicities in the Census like New Zealander or Kiwi.
The official ethnicities that have a "tick box" on the 2018 Census are New Zealand European, Maori, Samoan, Cook Islands Maori, Tongan, Niuean, Chinese, Indian and Other.
Hosking hoped Statistics New Zealand would make Pākehā visible on the Census, either in the same category as NZ European or in its own category.
"My long-term goal is to get Pākehā back in there in some form or other. I just want it there."
A 2018 Census spokeswoman said that Pākehā was a synonym for NZ European and was coded as such. People can select Pākehā by ticking "other" and entering it in. Pākehā was included in the 1996 Census form on the same tick box as NZ European.
"It is not standard practice for questions on the census to include multiple synonyms for the same category on the questionnaire form, which is why the forms following 1996 do not include both New Zealand European and Pākehā," she said.
Statistics NZ reviews ethnicity classifications periodically but it was unlikely Pākehā would be added any time soon, the spokeswoman said.
"Consistency of output data and questionnaire wording is a key consideration for customers using census data, and important for measuring concepts such as ethnicity over time.
"As such, it is unlikely that the structure of the ethnicity classification will change in the near future with regards to the terms of Pākehā or New Zealander."
Census letters have started arriving in letterboxes ahead of Census day on March 6.
Information from the Census helps determine how billions of government dollars are spent across New Zealand.
The information collected is about everyone in New Zealand, it can be used to inform decisions and make plans about services and where they should be.
Councils, iwi, and businesses also use Census information to help work out the core needs of their area or services.
The 2018 Census team have been contacted for comment.
How to participate in the 2018 Census
• Every household will receive an access code letter.
• It contains all the information a household needs to take part in the census online.
• Paper forms will still be available for those who prefer them.
• Once a household receives their letter, they can contact 0800 CENSUS (0800 236 787) to request paper forms, which will be posted to them.
• Stats NZ will include a freepost envelope for them to be returned.
Source: Stats NZ
More information on the Census
• The Census is an official count of how many people are in New Zealand. It's a snapshot of the people who live here and the places they call home.
• The data collected is used to inform important decisions, including where to spend taxpayers' money on services like schools and hospitals.
• The Census is on Tuesday, March 6.
• The funding for the 2018 Census is spread over five years, totalling $119 million.
Source: Stats NZ
