TECHNICAL NOTE OLD BASIS ESTIMATES
OLD BASIS ESTIMATES
1 Prior to running the 2005-06 Agricultural Census, the ABS had maintained its own register of agricultural establishments. However, it was increasingly difficult to maintain this list, and users were questioning the accuracy of some commodity data.
2 The ABS investigated a number of alternatives for maintaining an agricultural business register and discussed these with key users of agriculture statistics. As a result of this, it was agreed that the ABS should move to a new frame sourced from the Australian Taxation Office's Australian Business Register (ABR) for the 2005-06 Agricultural Census.
3 The ABR-based register consists of all businesses on the ABR coded to an 'agricultural' industry, as well as businesses which have indicated they undertake agricultural activities. All businesses with a turnover of $50,000 or more are required to register on the ABR. Many agricultural businesses with a turnover of less than $50,000 have also chosen to register on the ABR.
4 Moving to the ABR-based register required changes to many of the methodologies used for compiling agriculture statistics. These included changes to the methods used for determining whether agricultural businesses were 'in-scope' of the collection, and also to ways the data were compiled. Please refer to the Explanatory Notes of ABS publication Principal Agricultural Commodities, Australia, Preliminary, 2005-06 (cat. no. 7111.0) for more information about the changes in scope and coverage.
IMPLICATIONS FOR USERS
5 The key implication of the move to the new register is that the 2005-06 Agricultural Census data will not be directly comparable with the historical time series of agriculture data. Consequently the estimates of Value of Agricultural Commodities Produced (VACP) for 2005-06 are also not directly comparable with the historical VACP time series for those estimates that draw on the 2005-06 Agricultural Census production quantities. To provide users with a way of comparing ('bridging') the 2005-06 estimate of gross VACP data with the historical time series, the ABS has prepared two sets of VACP estimates.
6 'New-basis' Agricultural Census production estimates were prepared for 2005-06 using the new ABR-based register and its associated statistical methodologies. These methodologies have been subjected to rigorous analysis and testing, with the resulting 'new basis' estimates representing the start of the new commodity and livestock series.
7 'Old-basis' Agricultural Census production estimates were also prepared for 2005-06 for selected principal commodities. These estimates are a best judgement approximation to what the 2005-06 estimates may have been if the ABS had continued to use the previous ABS-maintained list of establishments (with its associated statistical methodologies) to conduct the 2005-06 Agricultural Census.
8 Estimates of VACP for 2005-06 have been derived using both the 'Old' and 'New' basis production estimates (see paragraph 11).
INTERPRETING THE BRIDGED DATA
9 Users should recognise the preliminary nature of both sets of 2005-06 production and hence VACP estimates. They should also exercise a degree of caution in interpreting the tables as both the 'old-basis' and the 'new-basis' estimates are subject to sampling and non-sampling variability.
10 The non-sampling variability in the 'old-basis' 2005-06 production estimates, in particular, is expected to be significant due to difficulties in collecting, processing and estimating 'old basis' Agricultural Census data from a 'new basis' framework. For this reason, the 2005-06 'old-basis' VACP estimates should be used with considerable caution and movements between 2004-05 and 2005-06 considered as indicative only.
11 The following table allows users to compare VACP estimates for 2005 and 2006 for those commodities which used the 2005-06 Census for production quantities, subject to the caveats mentioned.
GROSS VALUE(a) - Year ended 30 June 2006
AUST. OLD BASIS(b)
AUST. NEW BASIS(c)
|Grain sorghum |
|Sugar cane for crushing |
|Total crops |
|Total agriculture |
|(a) Estimates for 2005 are final; estimates for 2006 are preliminary and may be subject to revision. Caution should be exercised in comparing 2005 and 2006 estimates. |
|(b) Used an ABS-maintained land-based frame (list of 'farms'). |
|(c) Used the Australian Business Register-based frame (list of agricultural businesses). |
|(d) Data for 2006 old basis are initial bridged estimates and subject to revision. Caution should be exercised in comparing 2005 and 2006 estimates. |