Methodology

Overview

Small Area Labour Markets (SALM) presents estimates based on the Structure Preserving Estimation (SPREE) methodology.

The purpose of SPREE is to produce small area unemployment, unemployment rate and labour force estimates that reflect the regional disparities of the Centrelink data, while being consistent with ABS Labour Force Survey estimates.

Given the level of disaggregation involved, the small area figures produced by SPREE are smoothed (i.e., averaged) over four quarters, to dampen the variability inherent in the small area estimates.

Source data

Three primary data sources are used to produce the SA2 and LGA estimates in SALM:

1. Current recipients of Youth Allowance (other), and current recipients of Newstart Allowance or JobSeeker Payment who are not on a zero rate of payment, by SA2.
2. ABS Labour Force Survey data by ABS Statistical Area Level 4 (SA4).
3. Participation rate data at the SA2 level from the Census of Population and Housing. The latest SALM estimates use 2016 Census data. Estimates prior to the March quarter 2014 use 2011 Census benchmarks.

How SALM estimates are produced

Estimating unemployment

SALM produces unemployment estimates using an iterative process.

• Step one apportions ABS unemployment at the SA4 level across each of the SA2s within that region based on the distribution of Centrelink JobSeeker/Newstart and Youth Allowance (other) beneficiaries at the SA2 level by sex.
• Step two benchmarks the estimates produced in step one to ABS unemployment estimates by age, sex and marital status at the Greater Capital City Statistical Area (GCCSA) level.

These steps are repeated until the SALM unemployment estimates for the SA2s in each SA4 match the published ABS unemployment figures, and the age/sex/marital status groups in each GCCSA, for those regions and groups.

Estimating the labour force

Labour force size estimates are produced by:

• taking the participation rate for each SA2 from the Census. If an SA2 does not have a participation rate, the participation rate for the SA3 is used as a proxy;
• applying this to the latest available ABS estimated resident population (ERP) data for persons aged 15 and over for the SA2, to produce a labour force weighting for the SA2 within the SA4; and then
• allocating the total labour force for each ABS SA4 to the SA2s within that region according to the labour force weighting.

By using Census participation rates and the latest available ERP, the SA2 labour force estimates reflect any changes in the distribution of population within each SA4 that have occurred since the last Census.

Calculating the unemployment rate

Consistent with ABS methodology, unemployment rate estimates are produced by calculating the level of unemployment as a proportion of the labour force.

Producing LGA estimates

LGA estimates are produced by apportioning SA2 unemployment and labour force estimates using the latest available SA2 to LGA correspondence from the ABS.

Employment should not be derived from SALM

The SALM data are synthetic estimates based on ABS unemployment and Centrelink JobSeeker and Youth Allowance (other) beneficiary numbers and labour force data from the Labour Force Survey and the Census. As the production of SALM does not involve the use of any sources of, or attempt to estimate, the level of employment in an SA2 or LGA, employment estimates should not be derived from these statistics. For more information, please email the SALM inbox at SALM@jobsandskills.gov.au.

Greater disaggregations not available

Due to the significantly more pronounced variability of the data disaggregated below the SA2 or LGA level, it is not possible to derive reliable estimates for smaller population groups.

Accordingly, it is also not possible to estimate reliable unemployment and unemployment rate estimates for particular groups, such as sex or age cohorts, within an SA2 or LGA.

Estimates are not available for all SA2s and LGAs

Most SA2s and LGAs have a complete time series of data, with smoothed SALM estimates available from the December quarter 2010 onwards. For some regions, however, the available time series is shorter, while for other regions no estimates are available at all.

There are 3 reasons why data are not available for every SA2 and LGA:

• A break in series: some SA2s and LGAs have a ‘break in series’ so that only a partial time series is available. Most of these series breaks were the result of SALM moving from the 2011 to the 2016 version of the Australian Statistical Geography Standard (ASGS).
• The SA2 is considered too small: There are around 100 SA2s which Jobs and Skills Australia considers have too small a population for the production of reasonable estimates.
• Other factors: rarely, even though the region has a sufficiently large population, the methodology used in SALM will not produce estimates considered appropriate for publishing. This is why no estimates have been published for the SA2 and LGA of Aurukun since the June quarter 2017.

Smoothed estimates are not always available for published SA2s and LGAs

Four quarters of consecutive data are required to produce a smoothed SALM estimate at the SA2 or LGA level. Breaks in series can result in a number of quarters for which a smoothed estimate is not available for an SA2 or LGA, even if it would otherwise be published. 

In particular, smoothed estimates for SA2s or LGAs that experienced a break in the unsmoothed series between the March and June quarters 2019, due to the changeover to the 2016 ASGS are only available starting from the March quarter 2020.

For the June quarter 2019 to the December quarter 2019, the only available estimates for those SA2s or LGAs that have experienced a break are from the unsmoothed series. As is always the case for unsmoothed data, significant caution should be exercised when examining these figures, as they exhibit far greater volatility than the smoothed series.

Unsmoothed SALM estimates

The smoothed SA2 and LGA estimates are Jobs and Skills Australia’s official estimates of unemployment and the unemployment rate at those levels. It is recognised, however, that some advanced users may need access to the unsmoothed estimates, which are used to produce the official figures, and these are provided.

The unsmoothed series can exhibit very high levels of variability. Accordingly, we advise exercising extreme caution when using the unsmoothed series, whether it is using point-in-time estimates or interpreting quarter-to-quarter (or even year-to-year) changes.

Local Government Areas (LGAs)

There are around 540 LGAs in Australia.

• LGAs are based on the boundaries of the smallest government units (local councils) in Australia.
• Jobs and Skills Australia produces the SALM LGA estimates using the latest available SA2 to LGA correspondence from the ABS.

LGA boundary changes

LGA boundaries are determined by the governments of the states and the Northern Territory.

While there are often only minor, if any, changes year-to-year, sometimes there can be more substantial adjustments to this structure.

SALM transitions to a new LGA structure when a correspondence between SA2s and the new LGA structure is available from the ABS.

Boundary changes usually only lead to a small proportion of LGAs having a break in series. Smoothed data are not published for regions with a break in series until the fourth quarter after the break.

The June quarter 2023 release of SALM contains LGA estimates based upon the 2023 LGA structure. There were only minor differences between this and the previous LGA structure – see the ABS ASGS page on the LGA structure for more details.

Revisions to LGA series breaks

The introduction of the 2022 LGA structure in the June quarter 2022 edition of SALM involved the change to a new approach to population weighting in the SA2 to LGA correspondences provided by the ABS (when compared with SA2 to LGA correspondences used in previous editions of SALM).

This meant that, in some cases, the correspondence weights used in the SA2 to LGA correspondences, required to produce SALM LGA estimates, changed. As a result, there were a number of changes to which LGAs had a break in the unsmoothed series between the March quarter 2019 and June quarter 2019.

For more information and a list of the affected LGAs please see the SALM 2016 Changeover User Guide – 2022 Update.

2011 ASGS SA2 and LGA estimates

Jobs and Skills Australia maintains SALM SA2 and LGA estimates, based on the previous (2011) ASGS.

Due to the 2021 Census-related population rebenchmarking, 2011 Australian Statistical Geography Standard (ASGS) Statistical Area Level 2 (SA2) estimates from the September quarter 2016 up to the March quarter 2019 were revised in the December quarter 2022 publication. If users need to obtain the latest available 2011 ASGS SA2 or Local Government Areas estimates for areas that have had a break in series, please email the Small Area Labour Markets inbox at  SALM@jobsandskills.gov.au.