Individual home ownership (information about this variable and its quality)

Priority level

Priority level 3

We assign a priority level to all census variables: Priority 1, 2, or 3 (with 1 being highest and 3 being the lowest priority).

Individual home ownership is a priority 3 variable. Priority 3 variables do not fit in directly with the main purpose of a census but are still important to certain groups. These variables are given third priority in terms of quality, time, and resources across all phases of a census.

The census priority level for individual home ownership remains the same as tenure holder in 2013. Quality Management Strategy and the Information by variable for tenure holder (2013) have more information on the priority rating.

Overall quality rating for 2018 Census

Poor quality

Data quality processes section below has more detail on the rating for this variable.

The External Data Quality Panel has commented on the quality of this variable. Final report of the 2018 Census External Data Quality Panel has more information.

Caution is advised when using this variable at small geographies. Please see Recommendations for use and further information section below.

Subject population

Census usually resident population aged 15 years and over

‘Subject population’ means the people, families, households, or dwellings to whom the variable applies.

As this data relates to all people aged 15 years and over who were living in New Zealand, it includes those living in private dwellings (for example houses, units, apartments) and those living in non-private dwellings (for example student hostels, boarding houses, residential care for older people). It also includes teenagers and young people who live with their parents and do not (themselves) own their home.

This variable covers people whose home was unoccupied at census time and who were elsewhere in New Zealand. The tenure of household variable excludes households whose home was unoccupied at census time.

How this data is classified

Census Individual Home Ownership V1.1.0

Individual home ownership is a flat classification with the following categories:

01 Hold in a family trust

02 Own or partly own

03 Do not own and do not hold in a family trust

99 Not elsewhere included

‘Not elsewhere included’ contains the residual categories of ‘response unidentifiable’ and ‘not stated’.

The classification for this variable has changed since the 2013 Census. For 2018 a new category has been added – ‘Hold in a family trust’. Previously this was included in ‘own or partly own’.

The ‘Do not own and do not hold in a family trust’ category includes people who were renting, living in a home owned by other household members (for example parents), living in housing provided to them on a rent-free basis, or living in types of dwellings which they themselves would not own, such as a student hostel or residential care for older people, for example a rest home.

The Information by variable for tenure holder (2013) has more information

The ‘hold in a family trust’ and ‘own or partly own’ categories can be grouped for output if wished and used for comparing the 2018 Census data with earlier data.

The Standards and Classifications page provides background information on classifications and standards.

Question format

Individual home ownership is collected on the individual form (question 28 on the paper form).

Stats NZ Store House has samples for both the individual and dwelling paper forms.

There were changes to the question wording from the 2013 Census.

• In 2018 the question asked ‘Do you, or anyone else who lives here:

• hold this dwelling in a family trust?

• own or partly own this dwelling, with or without a mortgage?

• or neither of these.

• In 2013 the wording was ‘Do you yourself own, or partly own, the dwelling that you usually live in (with or without a mortgage)? The response options were ’Yes’ or ‘No’ with a note ‘If you hold the dwelling in a family trust, mark ‘yes’’.

There were differences in question format, wording and between modes of collection (online and paper form).

• The paper form stated an ‘or’ before the tick box ‘neither of these’ whereas the online form did not.

There were also differences in the way a person could respond:

On the online individual form:

• the individual home ownership question was only shown if the respondent was aged 15 years or over
• multiple response was not possible (Note: having a dwelling partly in a family trust and partly owned is a possible situation. The online help text stated: ‘If you have your home partly in a family trust and partly owned, select ‘hold it in a family trust’).

On the paper individual form:

• individual home ownership could be answered by all respondents (not just those aged 15 years or over)
• multiple responses were possible. These were resolved by the use of edits.

How this data is used

Outside Stats NZ

• Measure shifts in the approach taken by government to housing assistance and study the consequences of policy change.
• Analyse trends in home ownership by individual characteristics such as ethnicity and age (which is not possible with the tenure of household data).
• Formulate and monitor housing policy by central and local government.
• Has relevance in the areas of affordability, tenure security, suitability, and habitability.
• Provides a benchmark against which housing administrative data is assessed and developed.
• Could potentially be used to provide a framework and supplementary data for housing surveys.

Within Stats NZ

• Allows analysis of the personal characteristics (for example age, ethnicity) of home owners and non-home owners.
• Used in more in-depth outputs such as housing in Auckland to explore patterns and trends in home ownership at the individual level, including trends for different age groups and ethnic groups.

2018 data sources

The table below shows that there were no alternative data sources or imputation used to replace missing responses or responses that could not be classified for the individual home ownership.

The ‘no information’ percentage is where we were not able to source individual home ownership data for a person in the subject population.

Missing and residual responses

‘No information’ in the data sources table is the percentage of the subject population coded to ‘not stated’. In previous censuses, non-response was the percentage of the subject population coded to ‘not stated.’

Percentage of ‘not stated’ for the census usually resident population aged 15 years and over:

• 2018: 14.8 percent
• 2013: 5.4 percent
• 2006: 6.2 percent.

Responses that could not be classified or did not provide the type of information asked for such as response unidentifiable remain in the data, where we have been unable to find information from another source. In the data sources table, these residuals are included in the ‘Response from 2018 Census’ percentage.

For output purposes, as with 2013 and 2006 censuses, these residual category responses are grouped with ‘not stated’ and are classified as ‘not elsewhere included’.

Percentage of ‘not elsewhere included’ for the census usually resident population aged 15 years and over:

• 2018: 15.0 percent
• 2013: 5.4 percent
• 2006: 6.2 percent.

2013 Census data user guide provides more information about non-response in the 2013 Census.

Data quality processes

Overall quality rating: Poor quality

Data was evaluated to assess whether it meets quality standards and is suitable for use.

Three quality metrics contributed to the overall quality rating:

• data sources and coverage
• consistency and coherence
• data quality.

The lowest rated metric determines the overall quality rating.

Data quality assurance for 2018 Census provides more information on the quality rating scale.

Data sources and coverage: Poor quality

We have assessed the quality of all the data sources that contribute to the output for the variable. As no alternative data sources or imputation were used to replace missing responses, the final data sources and coverage quality rating for individual home ownership reflects the lower than expected response to the census overall and the high proportion of admin enumeration.

The rating for a valid census response is defined as 1.00. This is then multiplied by the overall percentage of responses from 2018 Census forms. The total score then determines the metric rating according to the following range:

• 98–100 = very high
• 95–<98 = high
• 90–<95 = moderate
• 75–<90 = poor
• <75 = very poor.

The low proportion of data from received forms therefore contributed to the score of 85.2, determining the poor quality rating.

Consistency and coherence: Poor quality

Individual home ownership data is not consistent overall with expectations across one or more consistency checks. There is an overall difference in the data compared with expectations and benchmarks. Where this difference occurs, this cannot be fully explained through likely real-world change, or a change in how the variable has been collected.

The 2018 Census individual home ownership data is not fully comparable with previous data for this variable. It does not show the expected trends at the national level.

Data quality: Poor quality

The data quality checks for individual home ownership included edits for consistency within the dataset and cross-tabulations to the regional council level

Significant data quality issues emerged during evaluation. Data is considered fit for use but there are limitations on how it can be used and interpreted. There are significant issues with respondent interpretation, coding, and/or classification problems.

Quality issues to note with this variable:

• overall the data appears to have some bias toward home owners. It seems that home owners were more likely to return census forms and answer this question than non-home owners.
• the information available on non-home owners in this data may not always fully represent the characteristics of people who do not own their home. The information available on home owners in this data is likely to be of better quality than that on non-home owners.
• the data may contain some incorrect responses due to respondent error or misinterpretation for example incorrect responses from people living in retirement villages, incorrect responses of ‘hold in a family trust’ from 15–19 year olds.

Recommendations for use and further information

When using this data you should be aware that:

• at small geographies, there will be variability in the percentage of missing data for a given area. This means some small geography areas will have poorer quality data than the overall quality rating.
• we advise caution due to data quality issues. Some patterns and trends in this data may not always fully reflect real-world change.
• for comparisons over time, the own and family trust categories in the 2018 data can be aggregated together.
• being a trustee of a family trust counts as holding the dwelling in a family trust. However, if a person is a beneficiary only and not a trustee, that does not count as holding the dwelling in a family trust. Some respondents may not be aware of this as this information was not included in the question or guide notes.

Contact our Information Centre for further information about using this variable