Statistical unit level data are aggregated to the output classifications of state/territory, industry division, employment size groups and sector.
A number of adjustments are applied to aggregates to account for FBT payments, differing reference month length and reporting anomalies.
FBT adjustment
Towards the end of the financial year, unadjusted STP data includes higher than usual changes in total wages and salaries paid. Most employers report lumped FBT payment amounts for eligible employees at the end of the financial year as part of FBT reporting obligations (particularly common in the Health care and social assistance industry). The inclusion of unadjusted FBT data in May and June reference months would significantly distort the wages and salaries paid for those months. Therefore, to remove the effect of these reporting arrangements, the ABS creates an adjustment factor to accrue the FBT amounts across all months of the relevant financial year. The adjustment is based at the stratum level (state/territory, industry division, employment size).
Calendar adjustment
To improve the comparability of estimates between calendar months, an adjustment has been applied to account for the differing number of days in each month. The adjustment standardises all months to an average length of days and is known as calendar adjustment. The calendar month estimate is converted to the calendar adjusted value using the following formula:
Reference month estimate = \(\frac{Calendar \ month \ estimate}{Number \ of \ days \ in \ month} * \frac{365.25}{12}\)
This type of adjustment is usually done as part of seasonal adjustment, however the statistics in this release are not yet fully seasonally adjusted.
As the ABS consolidates its understanding of STP data, methods will be further enhanced to improve the quality of these statistics and maintain the relevance of this indicator. As updated methods are implemented, more information will be provided within the Methodology.
Aggregate adjustment
Individual STP transactions are not amended. However, aggregate wages and salaries may be adjusted to remove the effect of significant reporting anomalies.
Aggregate adjustments are applied to the applicable state/territory by industry division by employment size level. The adjustments in each release are:
- calculated individually for each state/territory by industry division by employment size level, and
- removed when the adjustment is no longer required.
Adjustments are not currently possible below the level of state/territory by industry division by employment size. Therefore, finer level outputs like industry subdivision and sector can be adversely influenced by aggregate adjustments because they are applied equally to finer level data based on the existing proportion of industry division to its subdivisions and sectors.
As a result, month to month movements in subdivision and sector estimates may be more difficult to interpret in reference periods which see larger aggregate adjustment applied.