Census in Australia

The Census in Australia, officially the Census of Population and Housing, is the national census in Australia that occurs every five years. The census collects key demographic, social and economic data from all people in Australia on census night, including overseas visitors and residents of Australian external territories, only excluding foreign diplomats. The census is the largest and most significant statistical event in Australia and is run by the Australian Bureau of Statistics. Every person must complete the census, although some personal questions are not compulsory. The penalty for failing to complete the census after being directed to by the Australian Statistician is. The Australian Bureau of Statistics Act 1975 and Census and Statistics Act 1905 authorise the ABS to collect, store, and share anonymised data.
The first Australian census was held on 2 April 1911, but census data had been previously collected by individual states.
The most recent census was held on 10 August 2021. The next census will be held in early August 2026.

Geographical divisions

The census, like all ABS data, is collected and published in geographical divisions as defined by the Australian Statistical Geography Standard. The ASGS was released in 2011, replacing the former Australian Standard Geographical Classification. The Standard is reviewed and updated every five years to align with the census. The ABS also releases data divided into areas not managed by the Bureau, such as postcodes and Local Government Areas.

Privacy

The Census and Statistics Act 1905 and Privacy Act 1988 prohibit the ABS from releasing any personally identifiable census data to any government, private or individual entity.
In 1979, the Australian Law Reform Commission released Privacy and the Census, a report detailing legislative privacy measures related to the census. One of the key elements under question was the inclusion of names and addresses in census data. It was found that excluding names reduced the accuracy of the data; individuals were more likely to leave questions blank. Not collecting this data would also impair the ability of the ABS to ensure that all participants have responded.
The ABS protects personal information primarily through anonymisation of data. Personal information is stored separately from other census data, and separately from each other. Names are mutated into anonymised codes, which are then used to link data.

Destruction of personal information

Historically, the ABS has destroyed census forms or other census-related personal information after the census data processing period, roughly 18 months after the census.
Following a public consultation process before the 2016 census, it was found that Australians expected the ABS to hold their information for as long as there is a benefit to the community, and should be destroyed as soon as that need no longer exists. Following this process, the ABS has revised the retention period to four years after census, instead of 18 months. Concurrently, the ABS also improved their anonymisation techniques and limits access to addresses and anonymised names to when only necessary.

Census Time Capsule

Since [|2001], the ABS and National Archives of Australia have given respondents the option to have their complete census data, including name and address, stored in the Census Time Capsule. The capsule is stored securely at the National Archives for 99 years after each census and is released publicly at the end of that period. The first capsule opening will be on 7 August 2100.

Counting of Indigenous Australians

in contact with the colonists were enumerated at many of the colonial censuses. When the Federation of Australia occurred in 1901, the new Constitution contained a provision, which said: "In reckoning the numbers of the people of the Commonwealth, or of a State or other part of the Commonwealth, Aboriginal shall not be counted." In 1967, a referendum was held which approved two amendments to the Australian constitution relating to Indigenous Australians. The second of the two amendments deleted section 127 from the Constitution. It was widely believed at the time of the referendum, and is still often said, that section 127 meant that Aboriginal persons were not counted in Commonwealth censuses before 1967. In fact section 127 related to calculating the population of the states and territories for the purpose of allocating seats in Parliament and per capita Commonwealth grants. Its purpose was to prevent Queensland and Western Australia using their large Aboriginal populations to gain extra seats or extra funds. Thus the Commonwealth Bureau of Census and Statistics interpreted section 127 as meaning that they may enumerate Aboriginal persons but that they must be excluded from published tabulations of population. Aboriginal persons living in settled areas were counted to a greater or lesser extent in all censuses before 1967.
George Handley Knibbs, the first Commonwealth Statistician, obtained a legal opinion at the time that persons of 50 percent or more non-Aboriginal descent were not Aboriginal persons for the purposes of the Constitution. At the first Australian census in 1911 only those Aboriginal persons living near white settlements were enumerated, and the main population tables included only those of 50 percent or more non-Aboriginal descent. Details of Aboriginal persons of 50 percent or more non-Aboriginal descent were included in separate tables to Aboriginal persons of more than 50 percent Aboriginal descent. This practice was followed in all subsequent censuses up to 1966.
Since 1967, the ABS has considered Torres Strait Islanders a separate Indigenous people. Prior to 1947, Torres Strait Islanders were regarded as Aboriginal and excluded when not of 50 percent or more non-Aboriginal descent. In 1947, Torres Strait Islanders were considered to be Polynesian and in 1954 and 1961 were considered to be Pacific Islanders. In 1966, Torres Strait Islanders were again regarded as Aboriginal and excluded when not of 50 percent or more non-Aboriginal descent.

Australian Standard Classification of Cultural and Ethnic Groups

Ancestry data was included in the [|1986] census. It was found when the data was evaluated that people who filled in the census were not sure what the question meant and there were inconsistent results, particularly for those people whose families had been in Australia for many generations. There were no ancestry related questions in [|1991] or [|1996]. For 2001 it was decided that development of Government policies did need information about people who were either born overseas, or whose parents were born overseas. The questions were to mark the ancestries most closely identified with and to consider ancestry back as far as three generations. Respondents had the option of reporting more than one ancestry but only the first two ancestries they reported were coded for the census.
The results for 2001 were coded using the Australian Standard Classification of Cultural and Ethnic Groups. This classification of cultural and ethnic groups is based on the geographic area in which a group originated or developed; and the similarity of cultural and ethnic groups in terms of social and cultural characteristics. The classification is specific to Australian needs and was developed by the Australian Bureau of Statistics. The classification is based on the self-perceived group identification approach, using a self assessed response to a direct question. This approach measures the extent to which individuals associate with particular cultural or ethnic groups.

History

1828

Australia's first census was held in November 1828 in New South Wales, a British colony at the time. Previous government statistical reports had been taken from "musters" where white immigrants were brought together for counting. In 1828, the white population was 36,598: 20,870 settlers and 15,728 convicts. 23.8% of the population were born in the colony and 24.5% were women. There were 25,248 Protestants and 11,236 Catholics. Indigenous Australians were not counted.
Of the 36,598 people, 638 were living in what is now Queensland. There were also 18,128 people in Tasmania.

1881

In the mid-19th century the colonial statisticians encouraged compatibility between the colonies in their respective censuses, and in 1881 a census was held simultaneously in each of the colonies. This was part of a census of the British Empire. The questions posed in the colonies were not uniform and Henry Heylyn Hayter, who conducted the Victorian census, found that this caused difficulties in dealing with Australia-wide data.
The population of Australia counted in the census was 2,231,531.

New South Wales	Victoria	Queensland	Tasmania	South Australia*	Western Australia	Australia
741,412	858,605	211,040	114,790	276,393	29,561	2,231,531

At the time, the Northern Territory was part of South Australia and had 3,451 white people plus 6,346 Aboriginals in settled districts. Including the Northern Territory, South Australia had a total counted population of 286,211 people. The reported population of Western Australia did not include Aboriginal persons of more than 50 percent Aboriginal descent. The population of greater Melbourne was 282,947 and of Sydney was 224,939.

1891

1901

In 1901, there were 3,773,801 people counted in Australia.
Prior to federation, each colony had been responsible for its own census collection. The census held during the first year of Federation, 1901, was again collected by each state separately. When planning for the 1901 census it was clear that federation was soon to occur, and a uniform census schedule was adopted.