Definition: Estimated resident population (ERP) is the official Australian Bureau of Statistics (ABS) measure of the population of areas in Australia according to a usual residence population concept. Usual residence is that place where each person has lived or intends to live for six months or more from the reference date for data collection. It refers to all people, regardless of nationality or citizenship, who usually live in Australia, with the exception of foreign diplomatic personnel and their families. It includes usual residents who are overseas for less than 12 months. It excludes overseas visitors who are in Australia for less than 12 months.

In census years, ERPs are 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 post-censal years ERPs are 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.Population estimates for Australia and the states and territories are updated by adding to the estimated population at the beginning of each period the components of natural increase (births minus deaths, on a usual residence basis) and net overseas migration.

Estimates of the resident populations as at 30 June are released annually for all Statistical Areas Level 2 (SA2s) and Local Government Areas (LGAs) in Australia. The estimates are generally revised 12 months later and final estimates are available after the following census. 

Source: Australian Bureau of Statistics, Regional Population Growth, Cat. 3218.0 (2016 revised data was released on 31 July 2017. 2016-17 data is expected to be available in March 2018).