You can use this data confidently. Stats NZ rated it as high quality.
For more information, read about response rates below.
Stats NZ gives data an overall rating based on sources and coverage, consistency, and data quality.
Why am I seeing this?
This data is from the 2018 Census. The 2018 Census had low response rates, particularly for some areas of New Zealand and groups of people. Read more about this on Stats NZ's website.
Where information was missing or unreadable, Stats NZ attempted to use data from a range of places such as the 2013 census or administrative data that is collected by other government agencies. If that isn't available, Stats NZ use statistical models to predict what the missing data would have been. This is called imputation.
Things to be aware of
This is a multiple response variable, therefore the number of total responses will be greater than the number of respondents (e.g. a person who identifies as Samoan and Chinese would be counted once in each category).
When comparing these results to the 2006 and 2013 censuses, it is advisable to use percentages. The absolute change in count of people for each ethnic group is over-inflated by the additional data imputation and collection methods in 2018. In 2018, all people were assigned to at least one category.
A person may vary their reporting of their ethnicity, including the number of ethnicities they identify with, according to the context in which they are asked. This is a consideration when comparing the 2018 Census results with other sources. In addition, the 'as-you-type' online functionality of this census allowed for more detailed responses than in other data collections, including previous censuses.
Ethnicity is the ethnic group or groups a person identifies with or has a sense of belonging to. It is a measure of cultural affiliation (in contrast to race, ancestry, nationality, or citizenship). This demographic attribute is self-perceived, and a person can belong to more than one ethnic group.
As with the classification of the 2006 and 2013 Censuses, ‘New Zealander’ or ‘Kiwi’ responses were coded to ‘Other’, whilst ‘Pākehā’ was coded to ‘New Zealand European’.
Response rates and final data sources
The response rate from 2018 Census forms was 84.4%. In addition, 8.2% of responses were sourced from forms submitted during the 2013 Census. 6.2% were sourced from administrative data such as the births register, education enrolments, Ministry of Health, Corrections, and Ministry of Defence datasets. 1.2% of responses were imputed, while less than 0.1% were missing.
Some responses that could not be classified, or did not provide the type of information asked for, remain in the data where Stats NZ was unable to find information from another source. These are included in the response rate from 2018 Census forms.
Definitions
Census usually resident population count of New Zealand: a count of all people who usually live in and were present in New Zealand on census night. It excludes overseas visitors and New Zealand residents who are temporarily overseas.
Census night population count of New Zealand: a count of all people present in New Zealand on census night. This includes visitors from overseas who are counted on census night but excludes residents who are temporarily overseas on census night.
Private dwelling (home): A private dwelling accommodates a person or a group of people. It is not generally available for public use. The main purpose of a private dwelling is as a place of habitation, and it is usually built (or converted) to function as a self-contained housing unit. A home may be occupied or unoccupied (empty or residents away) on census night.
Geographically the census includes the North Island, South Island, Stewart Island, and the Chatham Islands, plus largely uninhabited islands including the Kermadec Islands, Three Kings Islands, Mayor Island, Motiti Island, White Island, Moutohora Island, Bounty Islands, Snares Islands, Antipodes Islands, Auckland Islands, and Campbell Island.
Changes to data collection/processing
The 2018 Census was a modernised census based on models used in 2016 by the Canadian and Australian statistical agencies and then applied in the New Zealand context. Stats NZ collaborated with census experts from both countries when designing the model.
Under the new model, how Stats NZ enabled/collected from the respondents changed from predominately field-based activities to 80 percent mail-out with a reduced field presence and increased communications, marketing and engagement. The way respondents completed their forms also changed, with a greater focus on online completion over paper. The majority of the population was encouraged to complete the census online using an internet access code mailed to their households before census night. The new collection model therefore relied on the public to self-respond, rather than wait for a visit from field staff. Field follow-up activities were also planned.
The main areas of change were:
- phasing the model (prepare, enable, remind and visit)
- strategies used across the different phases
- mailing out “call to action” letters with an internet access code and instructions on how to order paper forms, if required, as the first interaction with census
- reducing the number of field staff, with a new structure and roles
- outsourcing the recruitment functions for field staff
- introducing new field technology
- creating a new address frame (a list of all dwellings in New Zealand)
- an integrated communications campaign including community engagement
- a new approach to processing the census data.
The New Zealand Census of Population and Dwellings is the official count of how many people and dwellings there are in New Zealand. It provides a snapshot of our society at a point in time and helps to tell the story of its social and economic change. The 2018 Census, held on Tuesday 6 March, was the 34th New Zealand Census of Population and Dwellings. The first official census was run in 1851, and since 1877 there has been a census every five years, with only four exceptions.
Purpose of collection
Census information is used by government agencies, local authorities, businesses, community organisations, and the public for developing and implementing new policies, research, planning, and decision-making. It helps us make decisions about how to best use public funding, especially in areas of health, education, housing, and transport.
The census is also the primary source of information used for deciding the number of general and Māori electorates, along with data from the corresponding Māori Electoral Option.