Population Share by Major Ethnic Group
There are two sets of ethnic composition maps (see below for data sources and methodology). The first set shows the percentage of each broad age group in each territorial authority area that identified as belonging to one of New Zealand’s four major ethnic groups at the 2013 Census. The second set is based on Statistics New Zealand’s (2015) medium variant projections by major ethnic group for the years 2013, 2023 and 2038 (note that these projections have recently been updated).
Both sets of maps are labelled ‘percent share’, by which is meant that all data for each individual age group in the first set of maps sum to 100 across all ethnic groups, and data for all ethnic groups in the second set of maps similarly sums to 100, for each period. However, users should note that these data are based on Statistics New Zealand’s method of ‘multiple ethnic enumeration’, which means that people may be counted more than once (people are included in each major ethnic group they specify they belong to in the Census); thus, in most cases, total percentages in reality sum to greater than 100. This is particularly so among the younger age groups, where there are greater proportions of mixed ethnicity. To assist in understanding this issue of ‘ethnic overcount’, refer to the methodology notes below.
The data by age clearly show that European New Zealanders account for the dominant share at all ages, and this is especially noticeable at 65+ years; however, this is closely followed by substantial shares of Māori in many North Island territorial authority areas, especially among younger age groups. Reflecting this pattern, the South Island is disproportionately European at all ages.
The projections by ethnic group indicate that the South Island will continue to be predominantly European, although the Māori and Asian ethnic groups are each projected to increase their share. Across the North Island territorial authority areas, Māori also see an increased share in many, while European see a concomitant decrease.
Data sources and methodology:
The raw data for these maps were drawn from Statistics New Zealand (2015) Subnational ethnic population projections. However, in order to convert the data to population (percentage) shares, the issue of ‘ethnic overcount’ first had to be considered. As Statistics New Zealand’s website shows, when numbers by major ethnic group are summed, the result is greater than 100 per cent (Table 1). As explained elsewhere on the Statistics New Zealand website, this is because people may be counted more than once, depending on how many ethnic groups they state. In 2013, for example, just over half of the 598,605 usually resident Census night population identifying as Māori specified more than one ethnic group (Statistics New Zealand 2013: 5). When considered against the Census population head count (4.424 million), Māori enumerated in this way accounted for 14.9 per cent. While this approach accurately reflects social diversity, and is the method used for our maps, when all ethnic group responses are summed in this way, the resulting proportions sum to 112.6 per cent—that is, the population head count is exceeded by 12.6 per cent. This makes interpretation of the data difficult, because people are confused when percentages sum to more than 100. Another common approach, based on summing the responses and recalculating the percentages (Table 1), resolves the problem, but no longer adequately reflects the underlying social diversity.
Table 1: New Zealand usually-resident Census population by percentage stating major ethnic group, 2013
|Major Ethnic Group||% based on headcount||% based on summed total responses|
|Middle Eastern/Latin American/African||1.2||1.1|
Source: Statistics New Zealand 2013
We do not pursue here the issue of which output is better, but instead encourage users of ethnic group data to carefully read the relevant information on Statistics New Zealand’s website (see also reference list below). Here we simply draw attention to the relative impact of ethnic overcount by age and at subnational level (see ethnic overcount maps). Ethnic overcount is greater at younger ages because children are far more likely than their parents and grandparents to have been born into a multi-ethnic relationship; by contrast, ethnic overcount is minimal at 65+ years of age. Because of this, ethnic overcount is projected to increase over time. At territorial authority area and regional council level, ethnic overcount is greater, the higher the proportion Māori. As a result, there is an ethnic overcount gradient which runs from north to south, with jurisdictions in the North Island (where the proportions Māori are highest) having the highest measures of ethnic overcount, and those in the South Island having the lowest.
Cochrane W and I Pool (2017) Māori in New Zealand’s contemporary development Policy Quarterly Supplement 13: 47-54. http://igps.victoria.ac.nz/publications/PQ/2017/PQ-Vol-13-Supplementary-2017.pdf.
Statistics New Zealand (2005) Understanding and working with ethnicity data. A technical paper.
Statistics New Zealand (nd). The Statistical Standard for Ethnicity and When Individual Responses Exceed Input Storage - A Procedure For Unbiased Reduction. A technical paper for software developers.
Statistics New Zealand (2013). 2013 Census QuickStats about Māori. Available from www.stats.govt.nz.
Statistics New Zealand (2015) Subnational ethnic population projections 2013(base) – 2038.