New Zealand Statistical Association 2024 Conference

Walter Somerville and James Maguire

Stats NZ

Methodology for iwi affiliation in the 2023 Census

This is joint work with Tieta Vesty, Meenu Jose, Pip Bennett, Roimata Timutimu

The iwi affiliation variable is one of the highest-priority variables released in the 2023 Census. It is used to inform decisions that affect iwi and Māori, to provide iwi, iwi-related groups, and Māori with information to support their aspirations, and to meet the Crown’s partnership obligations under Te Tiriti o Waitangi. However, non-response in the 2023 Census means that some data is missing. To replace missing values for the iwi affiliation variable in 2023 Census, Stats NZ worked with Te Kāhui Raraunga Charitable Trust, under the Mana Ōrite Relationship Agreement (MŌRA), to investigate and develop a new methodology to incorporate information from alternative data sources. The alternative data sources used include historical census data as well as administrative data from the Ministry of Education and the Ministry of Social Development. The methodology also includes the use of parents’, grandparents’, or great-grandparents’ iwi affiliation where parental relationships are found in Department of Internal Affairs data. The use of alternative data sources increases the percentage of the 2023 Māori descent census usually resident population that have a value for iwi affiliation from 716,208 people (73.2 percent) to 954,042 people (97.5 percent). This presentation will discuss how we’ve worked together, the method used, and some of the key considerations.

The presentation "Methodology for Māori descent in the 2023 Census" by Amanda O'Connell and James Maguire presents similar points about the Māori descent variable.

The related presentation "Admin data quality for iwi affiliation in the 2023 Census" by Tieta Vesty and Meenu Jose will have more information about the administrative data sources.