TECHNICAL NOTE 2 ESTIMATION METHODOLOGY
GENERALISED REGRESSION ESTIMATION STREAM
1 The availability of Business Activity Statement (BAS) data collected by the ATO has provided the ABS with opportunities to improve the efficiency of collection designs and estimation for its business surveys, while at the same time reducing the reporting burden placed on businesses/organisations. Under taxation law, data may be passed by the Commissioner for Taxation to the ABS for specified statistical purposes. Accordingly, turnover and wages information sourced from ATO (BAS) data was used to improve the accuracy of the 2009-10 industry estimates which were produced using data items collected directly by the ABS from businesses/organisations.
2 The 2009-10 survey used generalised regression estimation. This estimation method enables maximum use of observed linear relationships between data directly collected from businesses/organisations in the survey and auxiliary information. When the auxiliary information is strongly correlated with data items collected in a survey, the generalised regression estimation methodology will improve the accuracy of the estimates. The auxiliary variables used in this survey were turnover and wages sourced from BAS data.
3 For the purpose of compiling the estimates in this publication, data for businesses/organisations as recorded on the ABSBR contribute via one of two categories (or 'streams') in accordance with significance and collection-related characteristics.
COMPLETELY ENUMERATED STREAM
4 The completely enumerated stream consisted of directly collected survey data for those units recorded on the ABSBR as having employment greater than 300, plus additional 'significant' units in the ABSMP and units significant to small state estimates.
The generalised regression estimation stream comprised directly collected data for those sampled units which are not in the completely enumerated stream and have turnover, in aggregate, above a certain threshold of BAS sales for that industry. The thresholds for each industry were as follows: 8511, 8512, 8531, 8533 ($50,000) and 8520, 8532, 8534, 8539, 8591, 8599 (2.5%).
STATE/TERRITORY AND REGION ESTIMATES
State estimation for this publication occurred through directly collected data and proration. Businesses/organisations which undertake multi-state operations received a more detailed survey form and were asked to supply key details of their operations by state and territory. These key data items were then used to prorate estimates for other data items by state/territory. The remaining units, were treated as single state operations, and all data published against the state of head office.
Region estimation for this publication occurred through directly collected data. All businesses/organisations were asked to provide key data by self identified categories, namely "Capital cities and suburbs", "Rural" and "Remote" areas. This categorisation was done at the National level only (not separately within states and territories).
GENERAL PRACTITIONER (GP) PRACTICE ESTIMATES
GP Practice estimates for this publication are a subset of the GP Medical Services
ANZSIC (8511). Practices are identified by the following characteristics:
- 'For profit'
- Two or more persons working for the practice
- Medical practices that combine all their operations under the one accounting entity
- Medical practices that are supported by an administrative service business
- Corporate practices