Except for illegal production, the scope of the Australian national accounts is exhaustive within the production boundary recommended in SNA93. Illegal activity (which relates mainly to illicit drugs) is left out of Australia's official statistics as it is difficult to measure with sufficient reliability. This is also typically the case internationally, although some countries have prepared indicative estimates.
As informal production is relatively unimportant in Australia, the ABS does not attempt to distinguish between the formal and informal sector in the sub-sectoring of the household sector. However, estimates are included for the value of owner-built construction activities and goods produced by households for own consumption such as food consumed on farms and home-grown fruit and vegetables. Unpaid housework including cooking and cleaning and volunteer services are not included, consistent with the recommendations of SNA93. However, estimates for these services have been prepared as satellite accounts.
Explicit upward adjustments are made to account for underground activity which is legal but is conducted in such a way as to avoid detection by taxation and other government authorities. The ABS recently completed a detailed review of its treatment of the underground economy in the estimation of GDP. The method used was to systemically analyse each component of GDP and make judgements as to the maximum feasible level of underground activity given available evidence from the Taxation Office and anecdotally. The results of the study were released in April 2004 in a paper titled The Underground Economy and Australia's GDP, which is available on the ABS web site.
The scope of some data collections may be drawn more narrowly for cost or other reasons. For example, the scope may exclude non-employing businesses, business under a certain size or some industries. A narrower scope is more likely for monthly or quarterly surveys. Data from the taxation system and other data sources allows these gaps to be filled. The annual economic collections are in fact designed around the availability of taxation data and the supplementation it brings to the coverage of small businesses including non-employing businesses. Non-profit institutions are in the main income tax exempt, so data for them has to be collected by the ABS. The annual economic survey strategy has recently been amended to improve the coverage of non-profit institutions.
The items capitalised for the first time by SNA93 relating to certain defence expenditures, mineral exploration, computer software and entertainment, literary and artistic originals have been implemented in the Australian national accounts. This resulted in an upward revision to the whole length of the series for gross fixed capital formation and GDP at the time of implementation in 1998.