THE PROPOSAL AND THE ASGC COMPARED
The proposal brings all the various boundary sets used by the ABS into the one scheme. The current ASGC will be replaced by the ABS Structures (except for LGAs). All of the structures are based on, or approximated by, mesh blocks. Conceptually much of the previous ASGC has been retained.
The concept of functional zones, implicit in the ASGC Main Structure, is explicit in new Main Structure. The significant change is the unlinking of LGAs from the Main Structure allowing the units to be designed around more objective statistical and geographical criteria. This permits greater freedom to define units on functional and population criteria that better reflect the real world and are more comparable in terms of population. The unlinking also permits greater stability as LGA changes do not have to be accommodated.
The data currently available at the LGA will still be available under the new structure. The only difference will be the position of LGAs in the overall classificatory scheme. Furthermore the ABS retains the ability to code to actual LGAs, rather than approximated LGAs, for many collections.
The Capital City Structure will be similar in concept to the current Capital City SDs.
Major Urban Concentrations
Statistical Districts will be replaced by MUCs. The minimum size for a MUC will be a regional centre with a population of 10,000 rather than 25,000 for Statistical Districts. The structure will combine coastal strip settlements and satellite settlements of larger urban areas in with the main centre. The reason is to better represent the interdependence of these centres and their regional significance.
The map below, of the Devonport-Burnie area of the Tasmanian North Coast, illustrates how a series of closely linked centres could be combined into one MUC. In this case the MUC stretches from Wynyard in the west to Port Sorrell in the east and includes the major centres of Burnie and Devonport.
Illustrative Devonport-Burnie Major Urban Concentration
The conceptual basis of the Remoteness Structure will remain identical to the current Remoteness Areas, but transferred to mesh blocks.
The definitions or urban and rural will be reviewed in 2008.
There is no replacement proposed for the rarely used Statistical Region Structure.
Indigenous Geography will be an Endorsed Structure.
The ABS and Endorsed Structures will be stable between censuses. This will make compiling and maintaining time series easier, although there is a cost in terms of the responsiveness of the structures to changes in the real world.
The proposal includes LGAs, postal areas, tourism regions and electoral divisions as Supported Structures. Suburbs are partially incorporated into the main structure, but they will form a Supported Structure in their own right. The Supported Structures include two new environment specific structures: Natural Resource Management Regions and Australian River Basins. Supported Structures will be maintained annually.
DATA AVAILABILITY UNDER THE CURRENT ASGC AND THE PROPOSED STRUCTURE
The tables below summarise the data available from the ABS below state level at the lowest level of disaggregation generally available under both the ASGC and the new statistical geography. Data available at one level in the classification are available at higher levels that are direct aggregations.
Data Availability Under the Current ASGC
|Level in the Classification ||Data Available ||Comment |
|Census Collection District ||Census data, Community Profiles, Socio-Economic Indexes for Areas (SEIFA) ||Available for other levels of the ASGC and Census Geographic Areas by aggregation from CDs |
|Statistical Local Area ||Agricultural Census, Tourism, Estimated Resident Population, Mortality, Births, Deaths, Building Approvals, some financial data from the Manufacturing Census, Business Demographics ||This data is also available at the LGA level as LGAs are aggregations of SLAs |
|Local Government Area ||Local Government Finance |
|Capital City SD/Rest of State ||Some Price Indexes, Survey of Motor Vehicle Use ||The Consumer Price Index is available for capital cities only |
|Labour Force Regions ||Labour Force, some Household Survey Data ||Non-ASGC unit, based on Statistical Region Structure |
|Reported Postcode ||Motor Vehicle Registrations ||Non-ASGC unit |
|Natural Resource Management Regions/Australian River Basins ||Agricultural Census and Surveys and Environmental Statistics ||Non-ASGC unit |
|Tourism Regions ||Tourism ||Non-ASGC unit approximated by SLA |
Data Availability Under the Proposal
|Level in the Classification ||Data Available ||Comment |
|Mesh Block ||Total population and dwellings on single mesh blocks. ||Detailed Census data will be available for higher levels of the new statistical geography by aggregations of mesh blocks. |
|SA1 ||Census data generally, Community Profiles, SEIFA |
|SA2 ||Agricultural Census, Tourism, Estimated Resident Population, Mortality, Births and Deaths, Building Approvals, some financial data from the Manufacturing Census, Business Demographics |
|SA4 ||Labour Force, some Household Survey Data |
|Capital City/Rest of State ||Some Price Indexes, Survey of Motor Vehicle Use |
|Local Government Areas ||Agricultural Census, Local Government Finance, Tourism, Estimated Resident Population, Mortality, Births and Deaths, Building Approvals, some Financial Data from the Manufacturing Census, Tourism |
|Postcode ||Motor Vehicle Registrations ||As reported |
|Natural Resource Management Regions/Australian River Basins ||Agricultural Census, Agricultural Surveys and Environmental Statistics ||Aggregations or close approximations of mesh blocks |
|Tourism Regions ||Tourism ||Approximated by mesh blocks |
The level of geographical disaggregation of data under the proposal will be either comparable or better than under the current ASGC.
There are practical reasons why data is not always available at a particular level. These are:
- large sample error for survey data
- large non-sample errors over small areas
These practical issues will remain, regardless of the geographical boundaries adopted. The population at each level of the proposal has been set to minimise the impact of these issues and to maximise the available data.
Some customised data are currently available at lower level than noted in these tables. This is made available to users who have a particular need for the data and are aware of the problems associated with fine geographical disaggregations of the data. This will continue under the proposal.
Under the current ASGC any data coded or derived at the CD level is potentially available for higher levels of the geography.
In the future the ABS intends to code and derive its data at the mesh block level. Therefore any ABS data will be potentially available for any unit which is an aggregation of mesh blocks. It will ultimately be possible for clients to get data from the ABS on any customised set of boundaries based upon or accurately approximated by mesh blocks given the constraints of confidentiality, and sample and non-sample error. Approximations of reasonably large areas by mesh blocks are likely to be very accurate as mesh blocks generally equate to areas containing 30 to 60 households (a population of approximately 100 people).
The ASGC was published annually with additional Census Geography; and Urban Centres and Localities published soon after each Census. The new Australian statistical geography will be published before each Census, however concordances to the Supported Structures will be published annually. The publication frequency of mesh blocks is still under consideration. They will be published with Census figures every 5 years, consideration is being given to publishing the boundaries between Censuses.