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CHAPTER 27. JOB VACANCIES SURVEY
Labour Statistics: Concepts, Sources and Methods was originally released in 2001 in both electronic and paper versions (cat. no. 6102.0). The paper publication will not be rereleased. However, the web version (cat. no. 6102.0.55.001) is being updated on an ongoing basis.
INTRODUCTION
27.1 The Job Vacancies Survey (JVS) was first conducted in 1974 and is a quarterly survey. The survey produces estimates of the number of job vacancies in Australia which are used as a leading indicator of employment growth, in monitoring of the Australian economy, and for formulating economic policy.
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SURVEY OUTPUT
27.2 Estimates are published quarterly in Job Vacancies, Australia (cat. no. 6354.0). More detailed estimates are available on request.
27.3 The population of interest is civilian employee job vacancies, available for immediate filling on the survey reference date, excluding vacancies for jobs based outside Australia. The series compiled from the survey is:
27.4 Data published for the job vacancies series are available on the following bases: original; seasonally adjusted; and trend. See Chapter 17 for further explanation of original, seasonally adjusted and trend estimates.
27.5 Estimates from the survey are classified by sector, State/Territory and industry (ANZSIC Division).
27.6 Estimates are compiled according to the concepts and definitions outlined in Chapter 4 (employees) and Chapter 11 (job vacancies).
SCOPE
27.7 The scope of the survey is restricted to employing businesses. In addition, the standard scope exclusions for ABS labour-related business surveys (outlined in Chapter 25) apply to this survey.
SURVEY METHODOLOGY
27.8 Details of the total number of employee job vacancies available for immediate filling on the survey reference date are obtained on a quarterly basis from selected businesses. A telephone interview collection methodology is used.
27.9 The survey reference date for job vacancies is the third Friday in the middle month of the quarter.
27.10 Follow-up procedures are in place to obtain information from respondents who are unable to provide data at the time of the initial interview. Response rates for the survey averaged 98% in the 2005-06 financial year.
SAMPLE DESIGN
27.11 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). However, where the statistical unit is unable to provide information required for the survey, it may be split into a number of 'reporting units'. For further information on statistical units used in ABS business surveys refer to Chapter 25.
27.12 A probability sample of statistical units (employing businesses) is drawn from the ABS Business Register using the process outlined in Chapter 25. Variables used to stratify the survey frame are:
- State/Territory;
- industry - industry stratification is based on ANZSIC division; and
- employment size - the ranges used vary between States/Territories and industries.
27.13 Statistical units with benchmark employment greater than a set cutoff (this cutoff will vary for different States/Territories) are completely enumerated. Strata with a very small number of statistical units may also be completely enumerated. Where there is a sufficient increase in the number of units in such strata, they may become sampled strata.
27.14 In addition to constraints outlined in Chapter 25, sample selection is constrained by ensuring that there is minimum overlap with other labour-related business surveys.
SAMPLE SIZE AND ALLOCATION
27.15 Approximately 5,000 statistical units are selected in the sample to yield a live sample of approximately 4,700 units.
27.16 The sample is allocated optimally across the strata using a technique designed to minimise the variance of job vacancies estimates at both the national and State/Territory level.
SAMPLE ROTATION
27.17 The sample is updated each quarter to reflect changes in the ABS Business Register. Approximately 8% of the sample selected from the non-completely enumerated strata is replaced each quarter. This process is called sample rotation (see Chapter 25 for further explanation).
27.18 Sample rotation is implemented for the majority of strata, but is not implemented where the population of a stratum is so small that units rotating out of the sample would be rotated back in after only a short interval.
ESTIMATION
27.19 Number raised estimation is used in all strata.
27.20 For non-responding units in the sampled strata, the Live Respondent Mean method (outlined in Chapter 25) of imputation is used. For non-response units in the completely enumerated strata, an imputed growth rate is applied to the most recent reported data for the unit, provided that data have been reported in either of the two previous quarters. Growth rates are estimated from live CE sector respondents in the most recent cycle. Otherwise data is imputed based on the benchmark employment.
27.21 For non-responding units in the completely enumerated (CE) strata, an imputed growth rate is applied to the most recent reported data for the unit, provided that data have been reported in either of the two previous quarters. Growth rates are estimated based on data provided by CE respondents for the most recent quarter. Where data for non-responding CE units have not been reported in either of the two previous quarters, ratio imputation is used. The ratio of job vacancies to benchmark employment is calculated at industry division level for responding units from the current quarter. This ratio is then applied to the benchmark employment for the non-responding unit.
27.22 Survey outliers are treated using the 'surprise outlier' technique.
27.23 Adjustments are made to survey estimates each quarter to allow for births and deaths of businesses that have occurred up to the end of the survey reference period but which are not reflected on the survey frame. These adjustments, called Business Provisions, were introduced in November 1999.
27.24 For further information on estimation methods used in ABS Business Surveys, refer to Chapter 25.
TIME SERIES ESTIMATES
27.25 Both seasonally adjusted and trend estimates are produced for the job vacancies series at the Australia level only.
Seasonal adjustment
27.26 The series are seasonally adjusted from February 1984. JVS uses the concurrent seasonal adjustment method to derive seasonal factors. The seasonal factors are reviewed annually to take account of each additional year's original data. The review takes place in time for the results to be reflected in each November issue of Job Vacancies, Australia (cat. no. 6354.0).
Trend estimates
27.27 Trend estimates were introduced in August 1993, and are revised each quarter.
RELIABILITY OF THE ESTIMATES
27.28 Estimates from the survey are subject to both sampling and non-sampling error. The relative standard errors of survey estimates are published in Job Vacancies, Australia (cat. no. 6354.0).
27.29 The 'jack-knife' approach is used to calculate estimates of variance for this survey. For further information on the jack-knife technique for calculating variance, or on sampling and non-sampling error, refer to Chapter 17.
DATA COMPARABILITY OVER TIME
27.30 In order to provide a high degree of consistency and comparability over time, changes to survey methods, survey concepts, data item definitions, frequency of collection, and time series analysis methods are made as infrequently as possible. Significant changes have included:
| 1974 | Mail-based annual Job Vacancies Survey commenced.
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| 1977 | Introduction of smaller scale quarterly telephone-based survey.
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| 1978 | Annual and quarterly surveys discontinued.
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| 1979 | Quarterly survey reintroduced.
Treatment of Australian Public Service vacancies changed to exclude vacancies only available to public service employees.
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| 1980 | First collection of job vacancies registered with the CES (continued on annual basis).
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| 1982 | Collection of vacancies classified by sex discontinued.
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| 1983 | Overtime Survey merged with Job Vacancies Survey. Sample size increased, with selection from the ABS Business Register.
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| 1984 | Seasonally adjusted series produced for the first time (February). Annual seasonal reanalysis of data performed for the November reference period.
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| 1985 | Job vacancies data published by sector for the first time.
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| 1988 | ABS publication of job vacancies registered with the CES discontinued.
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| 1993 | Trend estimates published for the first time (August).
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| 1994 | Survey redesigned on an ANZSIC industry basis. Industry data backcast on ANZSIC basis. Sample rotation increased from approximately 5% to approximately 8% in rotating strata. |
| 1998 | Treatment of Australian Public Service vacancies changed (from being excluded to being included) after vacancies made available to all Australian citizens.
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| 1999 | Introduction of Live Respondent Mean imputation for the sampled sector, and the Business Provisions adjustment for the private sector.
Overtime component discontinued.
Significant improvement in procedures, particularly coverage of vacancies within statistical units. |
| 2002 | Introduction of changes to the ABS Business Register and the ABS statistical units model arising from the New Tax System. These changes did not affect the continuity of the key statistical series. |
| 2003 | Collection of number of employees discontinued.
Publication of job vacancy rate discontinued. |
| 2006 | Concurrent seasonal adjustment method introduced, replacing the forward factor adjustment method previously used. |
FURTHER INFORMATION
27.31 For further details contact the Manager, Job Vacancies Survey on Perth (08) 9360 5357. |
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