IMPLICATIONS OF THE PROPOSAL
It is expected that the new Australian statistical geography will be published, with supporting material such as boundaries and concordances, in late 2009. From 2010, data using the new statistical geography will be progressively published. Data from the 2011 Census will be disseminated on the new geography.
Central to the proposal is the ability of the ABS and many other data providers to be able to code statistical data to mesh blocks. Significant progress has already been made with address based geocoding to mesh blocks being used within the ABS and available commercially.
Several issues still remain. Most of the address coding software uses G-NAF. This file currently has many addresses not geocoded accurately enough to assign an address to a mesh block. There is currently a lag of between 3 and 18 months getting new addresses on to G-NAF. These two issues are being actively addressed by the custodians of G-NAF, PSMA Australia. Address standards have not been uniformly adopted across the country, making it hard to match some addresses to G-NAF, particularly in remote areas. These issues are being pursued by the various state jurisdictions. The ABS is confident that in the medium term matching rates and mesh block coding rates will improve with G-NAF and the adoption of uniform address standards.
All ABS publications using the ASGC will need to be changed to accommodate the new statistical geography as will any publications produced by non-ABS organisations.
The changes will cause some disruption to time series. Data collected at the mesh block level can be readily recast on to any previous (or future) boundaries which can be approximated accurately by mesh blocks. Data not collected on mesh block, cannot be so easily recast onto the new boundaries. The ABS will create a series of concordances to facilitate this. In the long run, data comparability across time will be greatly improved as the new classification is more stable. Data from the 2006 Census will be available on mesh blocks thus providing a benchmark for population based time series.
Aspects of the ASGC are also entrenched in State and Commonwealth legislation; this legislation may need to be amended. A letter explaining the consequences of the review will be sent out to all Attorneys General if the recommendations are accepted.
In the long term the ABS would like mesh blocks to become the standard building block for administrative boundaries. This will greatly facilitate the comparison of statistics across different boundary sets.