Statistical Area Level 4
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.
Whole SA4s aggregate to Greater Capital City Statistical Areas and States and Territories. There are 108 SA4s covering the whole of Australia without gaps or overlaps. This includes 19 non-spatial special purpose codes including a new Outside Australia code. These non-spatial SA4s represent populations that are difficult to define geographically such as people who are in transit or have no fixed address. These are represented by Migratory – Offshore – Shipping and No Usual Address SA4s.
The Other Territories of Jervis Bay, Cocos (Keeling) Islands, Christmas Island and Norfolk Island are together represented by a single SA4.
SA4 design criteria
SA4s are designed using multiple criteria, listed below in approximate order of importance.
Most SA4s have a population above 100,000 people to provide sufficient sample size for Labour Force estimates. In regional areas, SA4s tend to have smaller populations of 100,000 to 300,000 people. In cities, SA4s tend to have larger populations of 300,000 to 500,000 people.
SA4s are designed to incorporate both labour supply (where people live) and demand (where people work). This enhances the quality of statistical outputs related to labour markets.
The ABS consulted with experts on labour market geography and undertook analysis of the Census of Population and Housing travel to work data to identify labour markets within Australia. The resulting labour markets are characterised by a large number of very small regional labour markets, a smaller number of medium sized labour markets around regional centres, and very large labour markets representing the major city centres. While this may be an accurate reflection of Australian labour markets, many of the regions did not meet the minimum population criterion.
SA4s are designed to represent the labour markets of the largest regional cities such as Wollongong, Bendigo and Townsville. SA4s present specific labour force data on these cities’ labour markets.
In outer regional and remote areas, labour markets tend to be small and localised around regional towns. SA4s in these areas represent aggregations of these labour markets based on geographic, social and economic similarities. SA4s which contain only remote and regional areas enable a picture of regional and remote labour force activity to be presented.
Smaller regional labour markets are combined based on travel to work interactions, as well as industry and regional similarities, to create SA4s of about 100,000 to 300,000 people. Medium sized regional centre labour markets that exceeded 100,000 people (for example Cairns, Qld) are preserved as far as possible as SA4s that directly represent the labour market, though in some cases small closely related labour markets are included in these SA4s. Very large labour markets of 300,000 to 500,000 people are split to reflect major employment hubs and their main labour supply catchments.
SA4 name criteria
The key criteria for SA4 names are that they be:
- have a maximum of 50 characters
- unique, that is not shared by any other SA4 in Australia
SA4s are named according to the areas they represent:
- Where an SA4 represents a labour market of a major city it is named after that city, for example “Bendigo”.
- Where an SA4 represents an employment centre within a larger city it is generally named to reflect both the larger city and the employment centre or part of the city that it represents, for example “Melbourne - Inner South”.
- Where an SA4 represents a collection of labour markets in regional areas it is named using either a description of that part of the state and territory or after one or more well-known regional areas that it closely replicates, for example “Latrobe – Gippsland”.
- Where the name does not identify it within Australia, it is generally preceded by the State or Territory name, for example “Western Australia - Wheat Belt”.
SA4 coding structure
SA4s are identified by a 3-digit hierarchical code. This comprises a 1-digit State or Territory identifier, which precedes a 2-digit SA4 identifier, unique within each State and Territory.