EXPLANATORY NOTES
INTRODUCTION
1 Estimates of the number of wage and salary earners (employees) in the public sector, and their quarterly gross earnings, are obtained from the quarterly Survey of Employment and Earnings - Public Sector (SEE). Information for both the private and public sectors was collected between the September quarter 1983 and the December quarter 2001 inclusive. Commencing with the March quarter 2002 survey, information is collected for the public sector only.
2 Care should be taken when comparing data for the public sector over time, as the privatisation of public financial and public trading enterprises has affected estimates at the sector level over recent years. Mainly Commonwealth government and state government enterprises, principally engaged in Electricity, gas and water supply, Transport and storage, Communication services and Finance and insurance, have been privatised.
3 The privatisation of Telstra Corporation has significantly impacted the public sector employment and earnings series. Telstra Corporation was effectively privatised on 20 November 2006. For the purpose of ABS statistics this change from public sector to private sector is effective from March quarter 2007.
4 Telstra Corporation is therefore no longer in the scope of the quarterly SEE, and Telstra data are excluded from the series from March quarter 2007. As a result, a trend break has been applied to the Commonwealth government and total public sector employees series between November 2006 and February 2007. See paragraphs 19-27 for more information about seasonally adjusted and trend estimates.
CONCEPTS, SOURCES AND METHODS
5 The conceptual framework used in SEE aligns closely with the standards and guidelines set out in Resolutions of the International Conference of Labour Statisticians. Descriptions of the underlying concepts and structure of Australia's employment and earnings statistics, and the sources and methods used in compiling these estimates, are presented in Labour Statistics: Concepts, Sources and Methods (cat. no. 6102.0.55.001).
SCOPE
6 All public sector employees who received pay in any pay period ending within the quarter are represented in the survey, except:
- members of the Australian permanent defence forces
- employees of overseas embassies, consulates, etc.
- employees based outside Australia
- employees on workers’ compensation who are not paid through the payroll
- directors and office holders of public sector enterprises who are not paid a salary.
SURVEY METHODOLOGY AND DESIGN
7 The SEE collects information each quarter, using mail questionnaires, from a sample survey of approximately 2,500 public sector employers selected from the ABS Business Register. Data for a number of government departments are collected electronically.
8 The statistical unit for the survey comprises all activities of a public sector employer in a particular state or territory. Statistical units are stratified by state, industry and employment size, and within each stratum, statistical units are selected with equal probability.
9 Each statistical unit is classified to an industry which reflects the primary activity of the organisation in the state or territory. Industry is classified according to the Australian and New Zealand Standard Industrial Classification (ANZSIC), 1993 (cat. no. 1292.0).
STATISTICAL UNITS DEFINED ON THE ABS BUSINESS REGISTER
10 The ABS uses an economic statistics units model on the ABS Business Register to describe the characteristics of businesses (and other organisations, including government departments), and the structural relationships between related businesses. The units model is also used to break groups of related businesses into relatively homogeneous components that can provide data to the ABS.
11 In mid 2002, to better use the information available as a result of The New Tax System, the ABS changed its economic statistics units model. The new units model allocates businesses to one of two sub-populations. The vast majority of businesses are in what is called the ATO Maintained Population, while the remaining businesses are in the ABS Maintained Population. Together, these two sub-populations make up the ABS Business Register population.
ATO Maintained Population
12 Most businesses and organisations in Australia need to obtain an Australian Business Number (ABN), and are then included on the ATO Australian Business Register. Most of these businesses have simple structures; therefore the unit registered for an ABN will satisfy ABS statistical requirements. For these businesses, the ABS has aligned its statistical units structure with the ABN unit. The businesses with simple structures constitute the ATO Maintained Population, and the ABN unit is used as the economic statistics unit for all economic collections.
ABS Maintained Population
13 For the population of businesses where the ABN unit is not suitable for ABS statistical requirements, the ABS maintains its own units structure through direct contact with the business. These businesses constitute the ABS Maintained Population. This population consists typically of large, complex and diverse businesses. The new statistical units model described below has been introduced to cover such businesses.
14 Enterprise Group: This is a unit covering all the operations in Australia of one or more legal entities under common ownership and/or control. It covers all the operations in Australia of legal entities which are related in terms of the current Corporations Law (as amended by the Corporations Legislation Amendment Act 1991), including legal entities such as companies, trusts, and partnerships. Majority ownership is not required for control to be exercised.
15 Enterprise: The enterprise is an institutional unit comprising (i) a single legal entity or business entity, or (ii) more than one legal entity or business entity within the same Enterprise Group and in the same institutional sub-sector (ie they are all classified to a single Standard Institutional Sector Classification of Australia sub-sector).
16 Type of Activity Unit (TAU): The TAU comprises one or more business entities, sub-entities or branches of a business entity within an Enterprise Group that can report production and employment data for similar economic activities. When a minimum set of data items is available, a TAU is created which covers all the operations within an industry sub-division (and the TAU is classified to the relevant sub-division of ANZSIC). Where a business cannot supply adequate data for each industry, a TAU is formed which contains activity in more than one industry sub-division.
17 For more information on the impacts of the introduction of the new economic statistics units model, refer to Information Paper: Improvements in ABS Economic Statistics [Arising from The New Tax System], 2002 (cat. no. 1372.0).
STANDARD INSTITUTIONAL SECTOR CLASSIFICATION
18 Institutional units are classified by broad economic functions according to the Standard Institutional Sector Classification of Australia (SISCA) which is a key component of the general national accounting framework. For more details refer to Standard Economic Sector Classifications of Australia (SESCA), 2002 (cat. no. 1218.0). Data split by the SISCA classification are available on request.
SEASONAL ADJUSTMENT
19 Seasonally adjusted data are available for the public sector employee series. Seasonal adjustment is a means of removing the estimated effects of normal seasonal variation from the series so that the effects of other influences can be more clearly recognised. Seasonal adjustment does not aim to remove the irregular or non-seasonal influences which may be present in any particular series. Influences that are volatile or unsystematic can still make it difficult to interpret the movement of the series even after adjustment for seasonal variation. This means that quarter-to-quarter movements of seasonally adjusted estimates may not be reliable indicators of trend behaviour.
20 The Survey of Employment and Earnings uses the concurrent seasonal adjustment method to derive seasonal factors. Concurrent seasonal adjustment uses data up to and including the current quarter to estimate seasonal factors for the current and all previous quarters. This process can result in revisions each quarter to estimates for earlier periods. However, in most instances, the only noticeable revisions will be to the seasonally adjusted estimates for the previous quarter and one year prior to the current quarter.
21 While seasonal factors for the complete time series are estimated each quarter, they are reviewed annually at a more detailed level to take into account each additional year's original data. The annual review is conducted on data up to and including the December quarter each year, with the results reflected in estimates released in the March issue of this publication. This annual review normally does not result in significant changes to previously published estimates.
22 Details about the method of seasonal adjustment of these series are available on request.
TREND ESTIMATES
23 Seasonally adjusted estimates can be smoothed to reduce the impact of irregular or non-seasonal influences. Smoothed seasonally adjusted series are called trend estimates.
24 The ABS considers that trend estimates provide a more reliable guide to the underlying direction of the original estimates, and are more suitable than either the seasonally adjusted or original estimates for most business decisions and policy advice.
25 Trend estimates, obtained by dampening out the irregular component from the seasonally adjusted series, are calculated using a centred 7-term Henderson moving average of the seasonally adjusted series. Estimates for the three most recent quarters cannot be calculated using this centred average method; instead an asymmetric average is used. This can lead to revisions in the trend estimates for the last three quarters when data become available for later quarters. Revisions of trend estimates will also occur with revisions to the original data and re-estimation of seasonal adjustment factors.
26 If a series is highly volatile then the trend estimates will be subject to greater revision for the latest few quarters as new data become available. However, it is important to note that this does not make the trend series inferior to the seasonally adjusted or original series.
27 For more information, refer to Information Paper: A Guide to Interpreting Time Series - Monitoring Trends (cat. no. 1349.0), or alternatively contact the Assistant Director, Time Series Analysis on (02) 6252 6345 or e-mail <time.series.analysis@abs.gov.au>.
INPUT INTO THE AUSTRALIAN NATIONAL ACCOUNTS
28 The SEE collects quarterly employee earnings for the public sector as one of the inputs in estimating the gross domestic product component of the Australian National Accounts. Prior to March quarter 2002 the SEE also collected these data for the private sector. From March quarter 2002 private sector data are collected in the Quarterly Business Indicators Survey and are published in Business Indicators, Australia (cat. no. 5676.0).
RELATED PUBLICATIONS
29 The following publications contain related information:
- Australian Labour Market Statistics (cat. no. 6105.0) - issued quarterly
- Average Weekly Earnings, Australia (cat. no. 6302.0) - issued quarterly
- Business Indicators, Australia (cat. no. 5676.0) - issued quarterly
- Employee Earnings and Hours, Australia (cat. no. 6306.0) - issued biennially
- Information Paper: Changes to ABS Measures of Employee Remuneration (cat. no. 6313.0) - issued 14 November 2006
- Information Paper: Improvements in ABS Economic Statistics [Arising from The New Tax System], 2002 (cat. no. 1372.0) - issued 6 May 2002
- Information Paper: Improvements to Australian Bureau of Statistics Quarterly Business Indicators, 2001 (cat. no. 5677.0) - issued 6 July 2001
- Labour Force, Australia (cat. no. 6202.0) - issued monthly
- Labour Statistics: Concepts, Sources and Methods (cat. no. 6102.0.55.001)
- Labour Price Index, Australia (cat. no. 6345.0) - issued quarterly
30 Current publications and other products released by the ABS are listed in the Catalogue of Publications and Products (cat. no. 1101.0). The Catalogue is available from any ABS office or the ABS web site. The ABS also issues a daily Release Advice on the web site which details products to be released in the week ahead.
ROUNDING
31 Where figures have been rounded, discrepancies may occur between sums of the component items and totals.