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EXPLANATORY NOTES
6 All job vacancies (as defined in the Glossary) of organisations covered in the survey are in scope, except those:
SURVEY METHODOLOGY AND DESIGN 7 The Job Vacancies Survey uses a sample survey methodology and collects information via telephone interviews. Approximately 5,000 employers, selected from the ABS Business Register, are included in the survey. 8 The statistical unit for the survey comprises all the activities of an employer in a particular state or territory based on the Australian Business Number (ABN) unit or Type of Activity Unit (TAU). Each statistical unit is classified to an industry which reflects the predominant activity of the business. The statistical units are stratified by state, industry division and employment size, and within each stratum, statistical units are selected with equal probability. 9 The sample for JVS, like most Australian Bureau of Statistics business surveys, is selected from the ABS Business Register which is primarily based on registrations to the Australian Taxation Office's Pay As You Go Withholding scheme. The population is updated quarterly to take account of new businesses, businesses that have ceased employing, changes in industry and employment levels and other general business changes. STATISTICAL CHANGES IMPLEMENTED IN NOVEMBER 2009 10 A sample redesign of JVS was undertaken to incorporate the new ANZSIC 2006 industry classification as the industry structure of ANZSIC 2006 is different to that of ANZSIC 1993. The ABS has also implemented some other statistical changes to improve survey frames at the same time as surveys adopted ANZSIC 2006. Employment benchmarks on the business survey frame have been updated to reflect more up-to-date information for use in stratification and estimation. There have been some changes to the Standard Institutional Sector Classification (SISCA), Public/Private and level of Government classifications and invalid industry and SISCA codes have been corrected for the ANZSIC 2006 frame. 11 The sample redesign, classification and the statistical changes impact on:
12 The JVS sample was redesigned to accommodate and exploit all of these changes. Because of the improved groupings of businesses for sampling purposes under ANZSIC 2006, the sample size has decreased from around 5,200 to around 5,000 businesses, with no loss to survey accuracy. IMPACT OF STATISTICAL CHANGES ON JVS ESTIMATES 13 The sample redesign and survey frame changes introduced in November 2009 are likely to have resulted in a shift in the level of the series from ANZSIC 1993 based estimates in May 2008, to ANZSIC 2006 based estimates in November 2009. Normally the ABS can provide a measure of the impact of a sample redesign by running a parallel sample on both bases for one or more cycles. However, due to the suspension of the JVS from August 2008 to August 2009 inclusive, any impact resulting from the sample redesign and survey frame changes can not be measured. Therefore caution should be used when comparing estimates from November 2009 onwards with estimates for May 2008 and previous periods. STATISTICAL UNITS DEFINED ON THE ABS BUSINESS REGISTER 14 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. The units model allocates businesses to one of two sub-populations, as follows: ATO Maintained Population 15 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, in which case 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 for these businesses as the statistical unit for all economic collections. ABS Maintained Population 16 For the population of businesses where the ABN unit is not suitable for ABS statistical requirements, the ABS maintains its own structure through direct contact with each business. These businesses constitute the ABS Maintained Population. This population consists typically of large, complex and diverse businesses and the statistical units model described below is used for these businesses. 17 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. 18 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 (i.e. they are all classified to a single Standard Institutional Sector Classification of Australia (SISCA) sub-sector). 19 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. INDUSTRY CLASSIFICATION 20 From November 2009, industry statistics presented are on the basis of Australian and New Zealand Standard Industrial Classification (ANZSIC), 2006 edition. This edition replaces the 1993 edition which has been in use since 1994. The 2006 edition of ANZSIC was developed to provide a more contemporary industrial classification system taking into account issues such as changes in the structure and composition of the economy, changing user demands and compatibility with major international classification standards. 21 Industry data up to May 2008 are only available on an ANZSIC 1993 basis. 22 For more information on the new industry classification, refer to Australian and New Zealand Standard Industrial Classification (ANZSIC), 2006 (cat. no. 1292.0). SEASONAL ADJUSTMENT 23 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. 24 Seasonal adjustments factors for November 2009 onwards are set to be the same as existed prior to the suspension of JVS (see below). Once there is a sufficiently long time series following the reinstatement of the survey, a review of seasonal adjustment factors will again be undertaken, which may result in revisions to the seasonally adjusted series. 25 The previous review of seasonal adjustment factors for private sector estimates was undertaken for May 2008. This review concluded that seasonality had weakened in recent quarters' private sector estimates, to the extent that the end of the series showed no seasonality. As a result, the published seasonally adjusted estimate for the private sector for February and May 2008 and from November 2009 onwards are the same as the corresponding original estimate. TREND ESTIMATES 26 Seasonally adjusted estimates can be smoothed to reduce the impact of irregular or non-seasonal influences. Smoothed seasonally adjusted series are called trend estimates. 27 The ABS considers that trend estimates provide a more reliable guide to the underlying direction of the data, and are more suitable than either the seasonally adjusted or original estimates for most business decisions and policy advice. 28 Recent trend estimates are not available in this issue of Job Vacancies, Australia due to the suspension of the survey in 2008/2009. These trend estimates will not become available until a sufficiently long time series has been established following the gap in the series. RELIABILITY OF ESTIMATES 29 Estimates are subject to sampling and non-sampling errors. For information on the reliability of estimates see the Technical Note. RELATED PUBLICATIONS 30 Users may also wish to refer to the following publications:
ROUNDING 31 Where figures have been rounded, discrepancies may occur between sums of the component items and totals. Document Selection These documents will be presented in a new window.
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