Sources of income - personal, family, extended family, and household 2013 Census (information about this variable and its quality)

##Where the data comes from

Sources of personal income – Question 30 on the individual form.

Question 30 is also used to derive sources of family, extended family income, and household income.

##How this data is classified

Sources of personal income

00 No source of income during that time

01 Wages, salaries, commissions, bonuses etc

02 Self-employment or business

03 Interest, dividends, rent, other investments

04 Payments from a work accident insurer

05 NZ superannuation or veterans pension

06 Other superannuation, pensions, annuities

07 Unemployment benefit

08 Sickness benefit

09 Domestic purposes benefit

10 Invalids benefit

11 Student allowance

12 Other government benefits, payments or pensions,

13 Other sources of income

99 Not stated

The same classification is used for family income, extended family income and household income Information on the number of income sources and the number of income sources excluding ACC and NZ Superannuation is also available.

For further information on the classifications used for sources of income, refer to the 2013 Census data dictionary.

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

##Subject population

The subject population for these variables are:

• sources of personal income: census usually resident population aged 15 years and over
• sources of family income: families in private occupied dwellings
• sources of extended family income: extended families in private occupied dwellings
• sources of household income: households in private occupied dwellings.

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’.

For personal income, substitute records were coded to ‘Not stated’ forming part of the total for ‘Not stated’.

Family income, extended family income, and household income are derived variables and therefore substitute rates are not applicable.

Non-response rates for 2013

• Sources of personal income: 7.2 percent, of which 4.9 were substitute records.
• Sources of family income: 1.3 percent.
• Sources of extended family income: 1.4 percent.
• Sources of household income: 4.6 percent.

Non-response rates for 2006

• Sources of personal income: 6.3 percent, of which 3.4 were substitute records.
• Sources of family income: 2.1 percent.
• Sources of extended family income: 1.5 percent.
• Sources of household income: 4.5 percent.

Non-response rates for 2001

• Sources of personal income: 6.2 percent, of which 2.4 were substitute records.
• Sources of family income: 1.3 percent.
• Sources of extended family income: 1.4 percent (including extended families with no source of income).
• Sources of household income: 3.7 percent.

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 to:

• derive sources of family income, sources of extended family income, and sources of household income, both by type and number of sources. This data is used with total income data for formulating social and economic policy, planning, monitoring programmes, and research. In particular, combining income with selected sources of income gives a better indication of the socio-economic status and well-being of individuals and households
• distinguish market and non-market sources of income in income distribution analysis. There is also considerable interest in the various sources of non-market income, for example by the Ministry of Education and for the New Zealand Deprivation Index.

##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.

Sources of Income 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 form compared with paper form

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 multiple responses to be selected as on the paper form – though 'No source of income' could not be selected with any income source and vice versa. It was greyed out.
• For people who stated that they were under 15 years or were overseas visitors, this question was greyed out, and they were not able to answer it unless they changed their answers to these two previous questions. When forms were completed on paper, it was possible for people under 15 years and overseas visitors to answer this question.

##Quality assessment of data and data quality issues for this variable

Overall quality assessment

High: fit for use – with minor data quality issues only. 2013 Census variable quality rating scale gives more detail.

Issues to note

Non-response rates for 2013:

• Sources of personal income: 7.2 percent, of which 4.9 percent were substitute records.
• Sources of family income: 1.3 percent.
• Sources of extended family income: 1.4 percent.
• Sources of household income: 4.6 percent.

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 data is fully comparable with data from the 2006, 2001, and 1996 Censuses. Changes in the data over this time period can be interpreted as real changes because there have been no changes in the way the data has been collected, defined, and classified.

For the 2006 Census, some minor wording changes were made to the categories to reflect benefit changes, but these have not affected comparability of the data.

##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)
• Household Economic Survey (HES)
• NZ Income Survey (NZIS)
• Linked Employer-Employee Database (LEED)
• Quarterly Employment Survey (QES).

The User guide for wage and income measures sets out each measure's design and purpose.

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.

##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:

• 'Sources of personal income' is a multiple response question. Respondents were asked to mark all the boxes that described a source of income for them. When a person reported more than one source, they were counted in each source they reported. This means that in sources of income tables, the sum of people or families will exceed the total number of people or families. Any percentages calculated on the total population will add up to more than 100 percent.
• Caution must be used when cross-tabulating sources of income with total income, as people, families and households may obtain income from more than one source.
• It is possible for people to have had more than one type of benefit during the 12 month period ending 5 March 2013.
• Where respondents marked 11 or more sources of personal income, their response was classified as 'Not stated'.
• The time reference periods are different for income variables and for other variables that may be cross-tabulated with income variables. For example, 'Work and labour force status' relates to the week prior to census day, while sources of personal income relates to the previous 12 months ending on census day, and 'Total income' relates to the 12 months ending on 31 March 2013. It cannot therefore be assumed that someone employed in the previous week has been employed all year and received only wage and salary income.
• Sources of family income and sources of household income are not available for a small number of families and households.

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