Iwi are the focal economic and political units of the Māori people of New Zealand. Iwi are based on the traditional Māori descent and kinship based hierarchy of:
- waka (founding canoe)
- iwi (tribe)
- hapū (sub-tribe)
- whānau (family).
Where the data comes from
Question 15 on the individual form.
How this data is classified
The first level of the output categories for Iwi (total response) are:
01 Te Tai Tokerau / Tāmaki-Makaurau (Northland/Auckland) region
02 Hauraki (Coromandel) region
03 Waikato / Te Rohe Pōtae (Waikato / King Country) region
04 Te Arawa / Taupō (Rotorua/Taupō) region
05 Tauranga Moana / Mātaatua (Bay of Plenty) region
06 Te Tai Rāwhiti (East Coast) region
07 Te Matua-a-Māui / Wairarapa (Hawke's Bay / Wairarapa) region
08 Taranaki region
09 Whanganui/Rangitīkei (Wanganui/Rangitīkei) region
10 Manawatū / Horowhenua / Te Whanganui-a-Tara (Manawatū / Horowhenua / Wellington) region
11 Te Waipounamu/Wharekauri (South Island / Chatham Islands) region
20 Iwi not named, but waka or iwi confederation known
21 Iwi named but region unspecified
22 Hapū affiliated to more than one iwi
44 Don't know
55 Refused to answer
77 Response unidentifiable
88 Response outside scope
99 Not stated
Iwi is a hierarchical classification with two levels. Level 1 has 19 categories, and level 2 has 144 categories. Published tables for 2013 output data at level 2 of the iwi classification.
For further information about this classification, refer to the:
For background information on classifications and standards, refer to the Classifications and related statistical standards page.
The subject population for this variable is the census usually resident population of Māori descent.
Note that the subject population for most other census data about Māori is the Māori ethnic group census usually resident population.
The subject population is the people, families, households, or dwellings to whom the variable applies.
Non-response and data that could not be classified
'Non-response' is when an individual gives no response at all to a census question that was relevant to them. The non-response rate is the percentage of the subject population that was coded to ‘Not stated’.
- Non-response rate for 2013: 3.1 percent.
- Non-response rate for 2006: 4.3 percent.
- Non-response rate for 2001: 5.4 percent.
Not elsewhere included
Non-response and responses that could not be classified or did not provide the type of information asked for were grouped together and called 'Not elsewhere included'. ‘Not elsewhere included’ includes response unidentifiable, response outside scope and not stated.
- 3.3 percent of the subject population was coded to 'Not elsewhere included' in 2013, compared with 4.3 percent in 2006 and 5.4 percent in 2001.
For more information on non-response, refer to the 2013 Census data user guide.
How this data is used
Data from this variable is used to:
- monitor the performance of Treaty of Waitangi obligations by the Crown and iwi
- assist the allocation of resources and funds to iwi
- assist in iwi planning and social and economic development
- assist Waitangi Tribunal decisions on, for example, land ownership and fishing rights
- assist central, regional and local government agencies planning and providing services to iwi in areas such as housing, health, social welfare, and special assistance programmes
- assist local government in the administration of the Resource Management Act 1991.
Data quality processes
All census data was checked thoroughly during processing and evaluation, to ensure that it met quality standards and is suitable for use. These quality checks included edits.
All data must meet minimum quality standards to make it suitable for use.
A quality level is assigned to all census variables: foremost, defining, or supplementary.
Iwi is a defining variable. Defining variables cover key subject populations that are important for policy development, evaluation, or monitoring. These variables are given second priority in terms of quality, time, and resources across all phases of a census.
Mode of collection impacts – online form compared with paper form
The online forms had built-in editing functionality that directed respondents to the appropriate questions and ensured that their responses were valid. As a result of this, data from online forms may be of higher overall quality than data from paper forms. The significance of this will depend on the particular type of analysis being done. There will always be a mode effect but this cannot be measured. Statistics NZ design and test to minimise the effects of mode for all questions.
There were differences between how the forms were completed online and on paper for this variable:
- If respondents gave a New Zealand address in question 5 and marked 'No' or 'Don't know' to the Māori descent question on the online form, the iwi question was greyed out so the respondent could not answer it unless they changed their answer to the Māori descent question. When forms were completed on paper it was possible for overseas visitors to respond to these questions.
- The online form allowed only one response to be selected for the yes/no tick boxes for the 'Do you know the name(s) of your iwi' question. If a further response was selected, the previous response was unchecked. Multiple responses to this question were possible when forms were completed on paper.
- On the online form, it was only possible to give text responses if the Māori descent question was marked 'Yes'. If the respondent selected 'Yes', a text box appeared and the respondent could enter up to five iwi. As with the paper form each box to enter an iwi name was followed by a box to enter the rohe.
Quality assessment of data and data quality issues for this variable
Overall quality assessment
Moderate: fit for use – with some data quality issues to be aware of, to High: fit for use – with minor data quality issues only. 2013 Census variable quality rating scale gives more detail.
Issues to note
- The non-response rate for iwi is low (3.1 percent).
- A significant proportion (16.6 percent) of people of Māori descent reported that they did not know the name(s) of their iwi in 2013, compared with 18.5 percent in 2006 and 15.9 percent in 2001. (However, this does not adversely affect the quality of the data as 'Don't know' is a valid response).
- All individual iwi categories are fit for use. While there may be an over-count for 'Region unspecified' categories, the counts in the 'Region unspecified' categories are down from 2006 (and 2001). Therefore, these categories are also considered fit for use.
- A team of specialist process operators were employed to ensure that responses in te reo Māori and iwi responses were coded as accurately as possible.
For more information on non-response refer to the 2013 Census data user guide.
Comparing this data with previous census data
This data is highly comparable with data from the 2006 and 2001 Censuses. Changes in the data over this time period can generally be interpreted as real changes. There may be a small component of change over time that is due to minor changes in the collection, definition, or classification of the data.
There are some minor differences affecting the comparability of this data with data from 2001 and 2006 Censuses. The classifications used in 2001 and 2006 were different from those used in 2013.
Between 2013 and 2006, the following changes were made to the iwi categories that were used in the classification.
- 2110 Ngāti Apa, region unspecified; previously 2110 Ngāti Apa, area unspecified
- 0203 Ngāti Maru (Hauraki); previously 0203 Ngāti Maru (Marutuahu).
- 1008 Ngāti Kauwhata; previously coded to 1004 Ngāti Raukawa (Horowhenua/Manawatū).
Between 2006 and 2001, the following changes were made to the iwi categories that were used in the classification.
- 0209 Ngāi Tai (Hauraki); previously Ngāti Tai
- 0412 Ngāti Tahu-Ngāti Whaoa (Te Arawa); previously Ngāti Tahu (Te Arawa)
- 0506 Ngāi Tai (Tauranga Moana / Mātaatua); previously Ngāi Tai
- 1113 Ngāti Apa ki Te Rā Tō; previously Ngāti Apa ki te Waipounamu.
There were also a number of minor name changes (primarily with macron placement, hyphenation, and capitalisation) to other iwi categories.
- 0710 Ngāti Pāhauwera; previously coded to Ngāti Kahungungu ki Te Wairoa
- 0711 Ngāti Rākaipaaka; previously coded to Ngāti Kahungungu ki Te Wairoa
- 1007 Ngāti Tama ki Te Upoko o Te Ika (Te Whanganui-a-Tara / Wellington); previously coded to Ngāti Tama (region unspecified).
Comparing this data with data from other sources
There are no alternative sources of this data available.
Further information about this data
All percentages in census publications have been calculated using 'Total people stated' as the denominator.
When using this data, be aware of the following:
- Iwi affiliation is a multiple response variable. Individuals can specify up to five iwi. Total responses will be greater than the number of respondents.
- Respondents who did not answer 'Yes' to the Māori descent question, but gave a valid iwi response are not included in the iwi counts. The Māori descent question design is intended to route people with no Māori descent to the question following the question on iwi affiliation, so that they do not answer the iwi question. However, in 2013, nearly 16,000 people gave a valid iwi but did not respond to the Māori descent question, compared with approximately 20,000 in 2006 and almost 17,000 people in 2001. There were also just over 1,000 respondents who ticked 'No' for the Māori descent question but who gave a valid iwi response. This compares with just under 2,000 in 2006 and over 1,000 in 2001. Although all iwi responses have been collected since 2001, the subject population is defined as those who said 'Yes' to the Māori descent question. The iwi responses of those who did not answer the Māori descent question, or said 'No' or 'Don't know', are not included in the output data.
- Statistics NZ is currently investigating how our statistical standards and classifications for Māori groupings (which includes iwi) can be improved to reflect the ways Māori identity could be recognised and represented in official statistics. The outcomes of this investigation will inform the future direction of statistical classifications for Māori groupings.
Contact our Information Centre for further information about using this variable.