STATE BY INDUSTRY SUBGROUP ESTIMATES
STATE BY INDUSTRY SUBGROUP ESTIMATES: JULY TO OCTOBER 2008
The 'one-in, two-out' sampling scheme used for the July to October 2008 reference months produced state by industry subgroup data of sufficient accuracy to release on a quarterly basis but monthly estimates that were too volatile to release. As a result, the state by industry subgroup estimates for the July to October 2008 reference months were suppressed. However, the broader level state and industry estimates continued to be available for this period.
The ABS has now produced modelled estimates for the July to October 2008 reference months at the state by industry subgroup level and they are available from the downloads tab of this issue.
The modelled state by industry subgroup estimates have been produced using an ARIMA model using the 15 years of data prior to July 2008 and data for November 2008. The original July to October 2008 estimates produced from the 'one-in, two-out' sample design are too volatile and would distort the modelled data. In addition, original estimates for December 2008 and subsequent months have been affected by the Federal Government's economic stimulus packages and other influences associated with global economic conditions. Use of data after November 2008 would bias the modelled data due to the uncertain affect on Retail Trade of these real world factors.
The modelled estimates were constrained as follow:
- the sum of the July to September 2008 months were constrained to the September quarter original estimates for State and Industry subgroup levels as released in the December quarter 2008 issue of Retail Trade Quarterly Indicators, Australia (cat. no. 8502.0)
- in addition, each of the July to September 2008 months was constrained to the Australian original estimate for each month as released in the previous issue of this publication
- the October 2008 month was only constrained to the Australian original estimate for October as released in the previous issue of this publication.
As a result of the inclusion of the modelled estimates, July to October 2008 current price estimates at the state and industry group levels have been revised. However, the Australian total for each of these months and the state and industry group estimates for September quarter 2008 have not changed. Changes to the October 2008 month state and industry group data have also resulted in revisions to the December quarter 2008 chain volume measures.