TECHNICAL NOTE 1 METHODOLOGY

Estimation methodology

Data streaming

Completely enumerated strea

Generalised regression estimation system

State/territory and region estimates


INTRODUCTION

1 The availability of Business Activity Statement 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 2008-09 industry estimates which were produced using data items collected directly by the ABS from businesses/organisations.


ESTIMATION METHODOLOGY

2 The 2008-09 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.

DATA STREAMING

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.

GENERALISED REGRESSION ESTIMATION STREAM

5 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 percentile of BAS sales for that industry. The percentile thresholds for each industry were as follows: 8601 (0.77%), 8609 (1.36%), 8710 (2.49%), and 8790 (1.73%).

STATE/TERRITORY AND REGION ESTIMATES

6 State and region estimation for this publication occurred through a combination of directly collected data and proration. All businesses/organisations were asked to provide key data by capital city/suburb and other areas. In addition, businesses/organisations which undertake multi-state operations received a more detailed survey form and 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 and region. The remaining units, including government organisations, were treated as single state operations, and all data published against the state of head office.