Feature Article - Analysis of Agriculture Survey Coverage, 2001-2002
The introduction of The New Tax System in July 2000 provided the Australian Bureau of Statistics (ABS) with the opportunity to improve its economic statistics by introducing new statistical infrastructure and using data available from the taxation system to, among other things, improve frame coverage, sample design and estimation methodologies. These opportunities are described in two information papers released by the ABS, ABS Statistics and The New Tax System (cat. no. 1358.0) released in April 2000 and Improvements in ABS Economic Statistics (Arising from The New Tax System)(cat. no. 1372.0) released in May 2002.
When implementing The New Tax System, the Australian Taxation Office developed the Australian Business Register (ABR) to record details of all businesses registering an Australian Business Number (ABN). The introduction of the ABR provided the ABS with an opportunity to assess and improve the coverage of farms on its own Business Register. To do this the ABS conducted the 2001–02 Agricultural Coverage Survey (ACS).
The main objectives of the ACS were to obtain structural and commodity information about businesses on the ABR that could not be matched to farms on the ABS' Business Register. The survey provided valuable information about the type and nature (e.g. size, business and farm structure, etc.) of these units. Estimates from both the ACS and the 2001–02 Agricultural Survey were combined to produce estimates for the principal agricultural commodities at the national and state level for all farms with an estimated value of agricultural operations (EVAO) greater than or equal to $5,000.
As the ACS was only a 10% sample of farms on the ABR, the data from it needs to be used with caution pending the outcome of an Agricultural Census using the ABR.
NUMBER OF FARM ESTABLISHMENTS
The ACS results showed that there were an estimated 53,200 farms with EVAO greater than or equal to $5,000 not covered by the Agricultural Survey. While this represented 28.2% of the total number of farms, their area of holding was only 3.0% of the total area of Australian farms identified by both surveys. An estimated 25,000 farms were identified in the ACS as having an EVAO of less than $5,000.
The ACS collected area and production data for a wide range of agricultural commodities. Table 1 shows that at the national level the area of holding estimate from the 2001- 02 Agriculture Survey may be understated by around 3.0%.
For major broadacre crops (including cotton), the ACS data indicated that the estimates from the 2001-02 Agricultural Survey may be understated by between 1.3% and 5.0%. For sugar cane production this variation was 5.9%; for total sheep and pig numbers, between 4.0% and 5.0%; and for meat and milk cattle between 9.6% and 12.7%.
To address the issue of farm establishment undercoverage, the ABS will adopt the ABR-based frame from the 2005–06 Agricultural Census. This change in frame coverage is expected to result in new levels for all data items collected. The ABS will investigate the impact of using the new frame in the Agricultural Census for key data items.
TABLE 1 ESTIMATES OF UNDERCOVERAGE, Agricultural Survey - 2001-02
|Farm establishments (no.)|
|Total area of holding ('000 ha)|
|Wheat for grain|
|Oats for grain|
|Barley for grain|
|Lupins for grain|
|Sugar cane cut for crushing|
|Sheep and lambs ('000)|
|Milk cattle ('000)|
|Meat cattle ('000)|
^ data subject to sampling variability equal to or greater than 10%, but less than 25%
* data subject to sampling variability equal to or greater than 25%, but less than or equal to 50%