Māori descent 2013 Census (information about this variable and its quality)

##Where the data comes from

Question 14 on the individual form.

##How this data is classified

1 Māori descent

2 No Māori descent

4 Don't know

7 Response unidentifiable

9 Not stated

For further information about this classification, refer to the:

• 2013 Census data dictionary
• Statistical standard for Māori descent
• Classification Code Finder.

For background information on classifications and standards, refer to the Classifications and related statistical standards page.

##Subject population

The subject population for this variable is the 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

'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: 9.9 percent, of which 4.8 percent were substitutes.
• Non-response rate for 2006: 9.6 percent, of which 3.3 percent were substitutes.
• Non-response rate for 2001: 10.3 percent, of which 2.2 percent were substitutes.

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'.

• 9.9 percent of the subject population was coded to 'Not elsewhere included' in 2013, compared with 9.6 percent in 2006 and 10.4 percent in 2001. These figures exclude 'Don't know'.
• In 2013, 2.1 percent of the subject population answered 'Don't know' to this question, compared with 2.0 percent in 2006 and 1.8 percent in 2001.

Note: For electoral purposes, Māori descent is imputed for those respondents who did not provide a clear ‘Yes' or 'No' response to the Māori descent question. In comparison, for census output purposes, Māori descent is not imputed.

For more information on non-response and substitute records, refer to the 2013 Census data user guide.

##How this data is used

Data from this variable is used:

• in conjunction with electoral registration data to calculate Māori electoral populations and provide information to the Representation Commission on the number of Māori seats required, as well as information for use in reviewing and establishing electoral boundaries
• in projections for the Māori descent population
• as a filter to the iwi question (in all censuses since 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.

Quality level

A quality level is assigned to all census variables: foremost, defining, or supplementary.

Māori descent 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 forms compared with paper forms

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:

• The online form allowed only one response to be selected for the Māori descent 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.
• Online respondents who indicated they were overseas visitors were not presented with the Māori descent question. However, on the paper forms it was possible for overseas visitors to answer this question. These responses are excluded from the subject population during data output and do not affect the quality of the data.

##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

• Non-response rate for 2013: 9.9 percent, of which 4.8 percent were substitutes.
• This variable has traditionally had a high non-response rate. An increased number of substitutes forms in 2013 has contributed to the high non-response rate, as these substitute forms are counted as 'Not stated' for the Māori descent question. Once the substitute forms are accounted for, the non-response rate is lower. However, the data collected is of high quality.

For more information on non-response and substitute records, refer to the 2013 Census data user guide.

##Comparing this data with previous census data

This 2013 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.

There have been minor changes to the Māori descent question in 2013, 2006, and 2001. The 2006 version of the question had a specific questionnaire routing instruction to 'Look for the 'Go to' instruction after you answer the question'. The question wording used in 2013 and 2001 did not include this routing instruction.

##Comparing this data with data from other sources

Census is the only information source that provides comprehensive information for small areas and small populations. However alternative sources of information about this subject are available:

• New Zealand General Social Survey (NZGSS)

Data from these alternative sources may show differences from census data for several reasons. These could be due to differences in scope, coverage, non-response rates, data being collected at different periods of time, alternative sources being sample surveys and as such subject to sampling errors, or differences in question wordings and method of delivery (self-administered versus interviewer-administered). Data users are advised to familiarise themselves with the strengths and limitations of individual data sources before comparing with census data.

Census data and data from the NZ General Social Survey should not be compared because of the limitations listed above.

##Further information about this data

All percentages in census publications have been calculated using 'Total stated' as the denominator.

When using this data, be aware of the following:

• Māori descent is used as a routing question for iwi. Respondents who indicate they have Māori descent are asked to proceed to the iwi question (Question 15) and give the names of their iwi. Respondents who don't have Māori descent or who don't know whether they have Māori descent are asked to proceed to question 16.
• 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.

Contact our Information Centre for further information about using this variable.