Statistical Area Level 4 (SA4s) are geographic areas built from whole Statistical Areas Level 3 (SA3s). SA4s are the largest sub-state regions in the Main Structure of the ASGS and are designed for the output of a variety of regional data, including data from the 2021 Census of Population and Housing. SA4 boundaries represent labour markets and the functional area of Australian capital cities respectively. They are designed with an emphasis on stability over time to support the time series of statistical releases such as the Quarterly Labour Force publication. These areas represent labour markets or groups of labour markets within each state and territory.