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Census of Population and Housing: Census dictionary
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The collection of names and addresses in the Census is a critical part of ensuring the quality and value of the Census.

Names are collected in the Census for many reasons, including: 

  • Making it easier for the person completing the form to provide the right information for each person in the household
  • Enabling high quality data linking for important research for projects, such as enabling more accurate estimation of Aboriginal and Torres Strait Islander life expectancy: Indigenous Mortality Project
  • Enabling the Post Census Review (also known as the post enumeration survey) to assess the quality of Census data. The Post Census Review is a short survey run in the month after the Census to determine how many people were missed or counted more than once, and to independently assess completeness of the Census.

Following a consultation process and Privacy Impact Assessment the ABS made the decision to retain names for up to 18 months and addresses for up to 36 months. The names will be used to generate anonymised keys that can be used to combine existing data sets to create richer and more valuable statistics for Australians.

See also Confidentiality, Name and address retention and Census time capsule.

Name and address retention

After the Census has been conducted and forms have been processed, the ABS will separate names and addresses from other information on the Census form (e.g. age, sex, occupation, level of education or income). The names and addresses are then stored securely and separately from other Census data and no one is ever able to view your name or address with your other Census data. This practice is known as the Separation Principle

The ABS will retain names for up to 18 months and addresses for up to 36 months.

See also Address, Census time capsule, Confidentiality and Name.

Name of employer

For each employed person, their employer's business name and address is requested on the Census form. This information is used to assist in classifying the employed person's Industry of employment (INDP).

See also Australian and New Zealand Standard Industrial Classification (ANZSIC), Confidentiality, Industry of employment (INDP) and Industry.

Negative income

Negative income occurs when the operating expenses are higher than the gross receipts (or revenue) of a self-employed person, business or a rental property. A person has negative income if these losses are greater than any income, benefits or allowances received from other sources.

See also Total personal income (weekly) (INCP).

Nominal child

A nominal child is any individual under 15 years of age who does not have a parent usually resident in the household but is instead assigned to a nominal parent from among other household members. Such children may be related to the nominal parent (e.g. as a nephew or niece) or not be related at all. Allocation of a nominal parent to a nominal child is determined by the application of certain coding rules. For more information refer to the Family, household and income variables, 2014.

See also Child and Family composition (FMCF).

Non-binary sex

Non-binary sex was the third response category to the sex question in the 2021 Census. The inclusion of this third category was to allow respondents to participate in the Census when the male and female sex categories did not accurately describe their sex.

See also Non-binary sex in the 2021 Census and Analysis of non-binary sex responses.

Non-family member

A person for whom there is no identified couple relationship, parent-child relationship, or other blood relationship with any of the other usual residents of the household. They may live within a family household, or they may form a non-family household either as a lone person or a group household.

A non-family member is a person who is either:

  • a lone person
  • a group household member or
  • an unrelated individual living in a family household.

See also Dwelling, Household, Relationship in household (RLHP), Visitors to a household and Visitors to Australia.


Non-response refers to the situation where a response to one or more questions (items) on the form was not answered.

Item non-response occurs:

  • where a household or person returns a form but does not answer one or more questions
  • where a household or person does not respond to the Census at all.

For the key demographic variables (sex, age, marital status and usual residence) we impute values where non-response occurs. The corresponding imputation flags for these variables indicate if the item was imputed.

Where non-responding persons have been imputed, the remaining questions are either set to 'item non-response' or 'not applicable', depending on the imputed age of the person.

For detailed information on non-response, see 2021 Census methodology.

See also Derivation and Imputation.

Not in the labour force

Persons not in the labour force are those people who, during the week prior to Census Night, were neither employed nor unemployed. They include people who were performing unpaid home duties, caring for children, retired, voluntarily inactive, permanently unable to work, in jail, trainee teachers, members of contemplative religious orders, and people whose only activity during the week prior to Census Night was jury service or unpaid voluntary work for a charitable organisation.

See also Labour force and Labour force status (LFSP).

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