Quality Statement

Label
Total family, extended family, and household income – 2023 Census: Information by concept en-NZ
Definition

Total income is the total before-tax income of a household, family or extended family (aged 15 and over) in the 12 months ended 31 March 2023. Total income sums the income band medians of each member of that unit (age 15 years and over). This information is collected and disseminated as income bands rather than in actual dollars.

Combined parental income for couples with children identifies the total before-tax (gross annual) income of both parents in the 12 months ended 31 March 2023. This information is collected and disseminated as income bands rather than in actual dollars.

en-NZ
Overall quality rating

Family income: Moderate quality
Extended family: Moderate quality
Household income: Moderate quality
Combined parental income for couples with children: Moderate quality

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

en-NZ
Priority level

Priority level 2
A priority level is assigned to all census concepts: Priority 1, 2, or 3 (with 1 being highest and 3 being the lowest priority).
Total family, extended family, and household income are priority 2 concepts. Priority 2 concepts cover key subject populations that are important for policy development, evaluation, or monitoring. These concepts are given second priority in terms of quality, time, and resources across all phases of a census.
The census priority level for total family, extended family, and household income remains the same as 2018.
The 2023 Census: Final content report has more information on priority ratings for census concepts.

en-NZ
Subject population

Total family income: Families in occupied private dwellings
Total extended family income: Extended families in occupied private dwellings
Total household income: Households in occupied private dwellings
Combined parental income for couples with child(ren): Couples with children in occupied private dwellings

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

en-NZ
How this data is classified

Total family, extended family and household income data is classified into the following categories:

Census Income bands V2.0.0 - Level 1 of 1

Code Category Code Category
11 Loss 21 $40,001-$50,000
12 Zero income 22 $50,001-$60,000
13 $1-$10,000 23 $60,001-$70,000
15 $10,001-$15,000 24 $70,001-$100,000
16 $15,001-$20,000 25 $100,001-$150,000
17 $20,001-$25,000 26 $150,001-$200,000
18 $25,001-$30,000 27 $200,001 or more
19 $30,001-$35,000 99 Not stated
20 $35,001-$40,000

Total income uses a 1-level flat classification as presented in the table above. Follow the link above the table to examine the classification and find more detail.

The 2023 Census classification for total income differs to the 2018 Census classification in the following ways:
  • 2018 Census’s lower bands (‘$1-$5,000’ and ‘$5,001-$10,000’) are replaced with ‘$1-$10,000’
  • an additional higher-level band is introduced (‘$150,001-$200,000’)
  • the top income band is changed from ‘$150,001 or more” to $200,001 or more’.

Standards and classifications has more information on what classifications are, how they are reviewed, where they are stored, and how to provide feedback on them.

en-NZ
Question format

The total family, extended family and household income variables are derived from the total personal income question on the individual form (question 37 on the paper form), and for individuals who usually reside in families, extended families and households.

For more information on the question format for:

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

en-NZ
Examples of how this data is used

Data-use outside Stats NZ:

  • combined with sources of household income, to give a better indication of the socio-economic status and well-being of households
  • to examine, in conjunction with other measures, inequity in income across ethnic groups, age groups, and genders.
  • in the determination of the Index of Socioeconomic Deprivation (NZDep). Household income is used to calculate equivalised income, which is a dimension of deprivation used to create this index.
  • by central government agencies, local authorities, private organisations, and researchers in the formulation of social policy, for planning and monitoring programmes, and for research purposes.

Data-use by Stats NZ:

  • to inform the selection of a sample for the Longitudinal Survey of Income and Housing and the Household Economic Survey (HES). Income is one of the key variables used so that the area-based samples are representative of different income bands.
  • census household variables are used as a comparison for admin household variables (which then guides changes to improve admin household variables).
en-NZ
Data sources

Total household, family and extended family income is sourced from the total personal income of each member of that unit (aged 15 years and over). For a breakdown of the data sources of total personal income, see Total personal income - 2023 Census: Information by concept.

For total personal income, alternative data sources for missing census responses and responses that could not be classified or did not provide the type of information asked for were used. Where possible, admin data or statistical imputation was used.

The table below shows the combinations of the various data sources used to source total household, family and extended family incomes.

Data sources for total family, extended family, and household income variables, 2023 Census
Source Total family income - percent Total household income - percent Total extended family income - percent Combined parental income for couples with child(ren) - percent
2023 Census response 85.2 80.0 67.3 84.1
2023 Census response and admin data 6.1 6.0 17.1 7.2
2023 Census response, admin data, and deterministic derivation 0.1 0.1 0.5 0.1
2023 Census response, admin data, deterministic derivation, and imputation <0.1 <0.1 0.1 <0.1
2023 Census response, admin data, and imputation 0.2 0.5 2.5 0.4
2023 Census response and deterministic derivation 0.5 0.4 1.0 0.7
2023 Census response, deterministic derivation, and imputation <0.1 <0.1 0.1 <0.1
2023 Census response and imputation 1.9 2.0 4.9 2.3
Admin data 5.4 6.8 5.4 4.6
Admin data and deterministic derivation 0.1 0.1 0.1 0.1
Admin data, deterministic derivation, and imputation <0.1 <0.1 <0.1 <0.1
Admin data and imputation 0.3 0.3 0.9 0.3
Deterministic derivation <0.1 <0.1 <0.1 <0.1
Deterministic derivation and imputation <0.1 <0.1 0.0 <0.1
Imputation 0.2 0.2 0.1 0.1
No information <0.1 3.5 0.0 0.0
Total 100.0 100.0 100.0 100.0
Note: Due to rounding, individual figures may not always sum to the stated total(s).

The following admin data sources were used, in priority order of use:
  • Inland Revenue
  • Ministry of Social Development
  • Working for Families.

Inland Revenue collects income as actual dollar values, but these are output into the income bands classification.

Editing, data sources, and imputation in the 2023 Census describes how data quality is improved by editing and how missing and residual responses are filled with alternative data sources (admin data and historical census responses) or statistical imputation. This webpage also contains a spreadsheet that provides additional detail on the admin data sources.

en-NZ
Missing and residual responses

Missing and residual responses represent data gaps where respondents either did not provide answers (missing responses) or provided answers that did not fit predefined categories (residual responses).

Where possible, alternative data sources have been used to fill missing and residual responses in 2023 and 2018 Censuses.

Percentage of ‘not stated’ for 2023:

  • Total family income: <0.1 percent
  • Total extended family income: 0.0 percent
  • Total household income: 3.5 percent
  • Combined parental income for couples with child(ren): 0.0 percent

Percentage of ‘not stated’ for 2018(1):

  • Total family income: 4.5 percent
  • Total extended family income: 8.3 percent
  • Total household income: 7.7 percent
  • Combined parental income for couples with child(ren): 3.3 percent

Percentage of ‘not stated’ for 2013:

  • Total family income: 11.3 percent
  • Total extended family income: 27.4 percent
  • Total household income: 15.1 percent
  • Combined parental income for couples with child(ren): 8.7 percent

(1) These proportions differ from those published in the Families and households: family, extended family, and household total income and sources of income - 2018 Census: Information by variable. The 2018 information by variable included an additional amount of non-response to account for households that information could not be derived for. This differed from the proportion counted as 'not stated' in published tables. The proportions included here reflect the data in published tables.

'Families and Households in the 2023 Census: Data sources, methodology and data quality' will have more information on missingness in household and family data. A link to the paper will be available from late 2024.

en-NZ
Data quality processes

Overall quality ratings:
Total family income: Moderate
Total extended family income: Moderate
Total household income: Moderate
Combined parental income for couples with children: Moderate

Data has been 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
  • accuracy of response.

The lowest rated metric determines the overall quality rating.

Data quality assurance in the 2023 Census provides more information on the quality rating scale.

Data sources and coverage:
Total family income: Moderate quality
Total household income: Moderate quality
Household income: Moderate quality
Total combined parental income: Moderate quality

All total family, extended family and household income variables, as well as the combined parental income for couples with children variable are rated moderate.

The quality of all the data sources that contribute to the output for the variables have been assessed. To calculate a data sources and coverage quality score for a variable, each data source is rated and multiplied by the proportion it contributes to the total output.

The rating for a valid census response is defined as 1.00. Ratings for other sources are the best estimates available of their quality relative to a census response. Each source that contributes to the output for that variable is then multiplied by the proportion it contributes to the total output. 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.

Data sources and coverage ratings were calculated by adding together all the data source ratings for the input variable (total personal income) for the individuals within the family, extended family, or household unit, and then dividing by the number of people in the unit. Individual income data source ratings are covered in more detail in Total personal income – 2023 Census: Information by concept.

Absentee records with ‘not stated’ income values were ignored in these calculations. If the overall family, extended family, or household income was coded to ‘not stated’, then that unit was given a data sources and coverage score of zero.

The average data sources and coverage scores for each unit were then added together and divided by the total number of records in the subject population.

There are missing counts where families and extended families belong to missed households. To account for this, an adjustment was included in the final metric one score for the 4.1% of households where information could not be derived.

Data sources and coverage quality rating table for total family, extended family, and household income variables, 2023 Census
Variable Weighted Metric 1 score Adjustment for households with unidentifiable composition Final Metric 1 score
Total family income 0.98 0.04 0.94
Total extended family income 0.96 0.04 0.92
Total household income 0.94 0.00 0.94
Combined parental income for couples with children 0.98 0.04 0.94
Note: Due to rounding, individual figures may not always sum to the stated total(s).

Consistency and coherence:
Total family income: High quality
Total extended family income: Moderate quality
Total household income: High quality
Total combined parental income for couples with children: High quality

Total family, household and combined parental income is consistent with expectations across nearly all consistency checks, with some minor variation from expectations or benchmarks which makes sense due to real-world change, incorporation of other sources of data, or a change in how the variable has been collected.

Total extended family income is mostly consistent with expectations across consistency checks. There is an overall difference in the data compared with expectations and benchmarks, which can be explained through a combination of real-world change, incorporation of other sources of data, or a change in how the variable has been collected.

Specific consistency and coherence considerations:

  • Extended family and combined parental income see more total incomes in higher income categories than expected. However, these are likely to be real-world changes rather than data quality issues.
  • There were high levels of admin data and increased proportions of missing information in cyclone impacted areas, notably Northland and Hawkes Bay.
  • There has been an increase since 2018 in the proportion of ‘Zero income’ sourced from admin data. New admin methodology for 2023 can assign respondents a ‘Zero income’, however, this ‘Zero income’ could be attributed to not being able to locate the data for those households, rather than the respondents having no income.
  • Areas with a high deprivation index (Northland, Gisborne, Hawke’s Bay, West Coast and Manawatu-Wanganui) have higher proportions of missing information for total household income in 2023.
  • Northland, Gisborne, Hawke’s Bay, West Coast and Manawatu-Wanganui have higher proportions of missing information for total household income in 2023.

Accuracy of responses:
Total family income: High quality
Total extended family income: Moderate quality
Total household income: High quality
Total combined parental income for couples with children: High quality

Accuracy of responses were assessed by looking at quality of input variables and also the quality of the units themselves. These include quality rating for total personal income, the methods for completing the relationships in the household matrices, and also analysis of people missing from households.

Accuracy of responses for total personal income has been assessed as high quality. For further information see Total personal income – 2023 Census: Information by concept.

Total family, household and combined parental income has only minor data quality issues relating to the methods for completing the relationships in the household matrices and also analysis of people missing from households. The accuracy of coding for the household matrix is high. Any issues with the data appear in a low number of cases.

There were significant changes introduced in the 2023 Census that impacted the counting of households and quality of household matrices. These were:

  • improvements in the methodology for using admin relationships to construct families and households when census relationships were missing
  • more extensive checks for errors, and higher quality manual corrections for households that had errors due to a dedicated and larger family coding manual intervention team
  • higher quality repatriation of people to the dwelling they usually live in.

These changes improved both the quality and accuracy of the data.

Extended families are more likely to contain a higher number of usual residents and are therefore more likely to be impacted by people missing from households. This will impact the ability to accurately derive total extended family income. Extended families with Māori or Pacific peoples usual residents have larger average household sizes than the general population and are therefore more likely to be impacted.

‘Families and Households in the 2023 Census: Data sources, methodology and data quality’ will have more information on the data quality of household and family data. A link to the paper will be available in late 2024.

en-NZ
Recommendations for use and further information

It is recommended that total family, extended family, and household income data can be used in a comparable manner to 2018 and 2013 Censuses.

When using this data, users should be aware that:

  • Care must also be taken when cross-tabulating total family, extended family and household income with sources of family, extended family and household income: The time reference periods are different for the two variables. Total family, extended family and household income relates to 12 months ending on 31 March 2023, in line with the tax year, while sources of income collects information for the 12 months ending 7 March 2023 (census night).
  • Improvements to the admin data sources for income have made improvements to total income data. This includes being able to retrieve income data for absentees who would have been classified as ‘not stated’ in previous censuses.
  • When using the data, users should be aware that the classifications for total personal income and total family, extended families and households income have been updated in the 2023 Census. Data users should be aware of the changes in classification when making time-series comparisons.
  • Not all people counted in the census usually resident population are part of the derivation of households and families, e.g. people who were admin enumerated at a meshblock rather than a dwelling level and people living in non-private dwellings. In addition, there are dwellings that were not occupied at the time of the census or not counted in the census. This means there will be families, extended families and households that are not counted in census outputs.
  • Care should be taken when looking at the time series as there were changes to the collection strategy, processing system, and household and family coding methodology between the 2013 and 2018 Censuses, and further improvements made to these for the 2023 Census. These improvements mean household and family data is of a higher quality in the 2023 Census compared to previous censuses.
  • The quality of relationships within households in the 2023 Census is higher than in previous censuses, including those for more complex households and households containing at least one member of Māori or Pacific Peoples ethnicity.

'Families and Households in the 2023 Census: Data sources, methodology and data quality' will have more information on changes to the methodology and data quality of household and family data. A link to the paper will be available from late 2024.

en-NZ
Information by variables from previous censuses

Information

History

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Revision Date Responsibility Rationale
50 14/01/2025 3:37:32 PM
47 1/11/2024 10:24:40 AM
46 31/10/2024 10:43:41 AM