Statistical revisions are carried out regularly in the Australian National Accounts, to reflect the most current information and estimation methods. For the December, March and June quarter National Accounts releases, the ABS limit revisions to the most recent quarters only. Annually, the ABS will apply revisions to a longer time series of selected estimates, which is referred to as a “historical revision". These revisions are first seen in the Annual National Accounts, and then in the September quarter release.
Historical revisions are important for several reasons including improved data quality, to update classifications and to improve international comparability.
Historical revisions in the national accounts have traditionally been undertaken on an ad-hoc basis. This involved holding back individual historical revisions until a time where many changes were put through in bulk. From 2021, the ABS adopted a policy of implementing targeted annual historical revisions. This is to ensure that the national accounts use the most up-to-date data available which best captures changes in a dynamic economy and is more responsive to user needs. The ABS will advise users on planned historical revisions in advance of publication.
The Annual National Accounts Supply-Use tables introduce revisions for the three open years as part of the standard benchmarking process. As such, the impact of the historical revisions can be difficult to isolate for the ‘open’ three years.