Preparation of estimated resident population (ERP) for areas within states and territories ("sub-state") uses data sourced from a variety of institutional environments. Much of the data is administrative by-product data collected by other organisations for purposes other than estimating the population.
In Census years, ERP is derived using data from the Census of Population and Housing and Post Enumeration Survey, with an allowance for the number of residents temporarily overseas (RTOs) at the Census date. For information on the calculation of sub-state ERP in Census years, refer to the Explanatory Notes of Regional Population Growth (cat. no. 3218.0). For information on the institutional environment of the Australian Bureau of Statistics (ABS), including the legislative obligations of the ABS, financing and governance arrangements, and mechanisms for scrutiny of ABS operations, please see ABS Institutional Environment.
For post-censal years ERP is calculated using mathematical models and indicator data such as dwelling approvals, Medicare enrolments managed by the Australian Government Department of Human Services and Australian Electoral Roll enrolments managed by the Australian Electoral Commission.
Statistics on building approvals are compiled by the ABS from permits issued by local government authorities and other principal certifying authorities; contracts let or day labour work authorised by commonwealth, state, semi-government and local government authorities; and major building approvals in areas not subject to normal administrative approval e.g. building on remote mine sites. For more information about this data source refer to the Explanatory Notes and Quality Declaration for Building Approvals (cat. no. 8731.0).
Medicare enrolment counts are provided by the Australian Government Department of Human Services. Medicare is Australia's universal health insurance scheme covering the large majority of Australians.
Enrolment counts by Census Collection District are provided by the Australian Electoral Commission (AEC). The AEC is responsible for conducting federal elections and maintaining the Commonwealth electoral roll.
Sub-state ERP is calculated to add to the independently and previously derived state and territory population estimates. For information on the data used to calculate state and territory ERP, see the Explanatory Notes of Australian Demographic Statistics (cat. no. 3101.0).
The total population estimates for each SA2 for post-censal years are then broken down into age and sex components. The estimates by age and sex are updated from the previous year's estimates using registered births and deaths data (see Australian Demographic Statistics (cat. no. 3101.0)), and synthetic estimates of migration based on the previous Census.