Enrolment projections overview – ACT federal redistribution

Updated: 24 October 2017

The enrolment data provided by the Australian Electoral Commission (AEC) have been prepared for the information of persons and organisations interested in the redistribution of federal electoral divisions in the ACT.

What enrolment data is supplied?

For the purposes of the redistribution, the AEC has made available:

  • enrolment in the ACT as at Monday 4 September 2017, the day on which the redistribution commenced
  • projected enrolment in the ACT at Thursday 13 January 2022

Enrolment as at Monday 4 September 2017 is supplied as these figures were used for the Electoral Commissioner's determination of the current enrolment quota under section 65 of Commonwealth Electoral Act 1918 (the Electoral Act). In making a proposed redistribution, the Redistribution Committee and the augmented Electoral Commission are bound by the Electoral Act to ensure that the number of electors in each proposed federal electoral division does not deviate by more than 10 per cent above or below the current enrolment quota. The current enrolment quota for the ACT was determined by the Electoral Commissioner to be 96,115 as at Monday 4 September 2017.

Projected enrolment at Thursday 13 January 2022 is supplied because, as far as practicable, the Redistribution Committee and the augmented Electoral Commission are required to ensure that the number of electors enrolled in each federal electoral division at Thursday 13 January 2022 (the projection time) will not deviate by more than 3.5 per cent above or below the projected enrolment quota.

A growth (%) figure is also provided. This is the estimated growth rate for the period Monday 4 September 2017 to Thursday 13 January 2022. The growth rate shown for each SA1 is calculated by subtracting the actual enrolment from the projected enrolment, then dividing by the actual enrolment. The result is expressed as a percentage.

The following information is provided for each federal electoral division in the ACT:

  • the name of each SA2 in the federal electoral division,
  • the identifier number of each SA1 or part SA1 in the federal electoral division,
  • the two sets of enrolment figures and the growth rates applicable to each SA1, part SA1 and SA2 and for each existing federal electoral division, and
  • total enrolment for the federal electoral division.

How are projected enrolment figures calculated?

Following a recommendation by the Joint Standing Committee on Electoral Matters (JSCEM) that the AEC and the Australian Bureau of Statistics (ABS) work together on enrolment projections, the ABS has supplied enrolment projections to the AEC using AEC enrolment data as the base. The ABS has used a cohort-component method to project the enrolment of each SA1. The methodology is detailed in the papers included with the projected enrolment.

Why are enrolment figures supplied at the SA1 level?

Enrolment figures are provided at the SA1 level, as this level is the smallest commonly used geographic building block. The SA1 figures are aggregated to show the totals for SA2s, which are comprised of a number of SA1s. Being somewhat larger than SA1s, SA2s may be more manageable for those who are interested in less detailed analysis.

The figures shown are broken down according to electoral division. Where a SA1 or SA2 crosses divisional boundaries, the SA1 or SA2 concerned will be listed in each electoral division in which electors are enrolled. Only those electors resident in that electoral division are included in the figures for such SA1s or SA2s.

How is the enrolment data provided?

Data is provided in the following files:

The SA1s and SA2s used for this redistribution are those which applied at the 2011 Census of Population and Housing.

Each file contains:

  • electoral division name;
  • SA2 name;
  • SA1 number;
  • enrolment as at Monday 4 September 2017;
  • projected enrolment as at Thursday 13 January 2022.

If technical difficulties are experienced in accessing this data, please contact the ACT Redistribution Committee/Secretariat.

Spatial data

The existing federal boundaries for the ACT are provided in a spatial format.

You will need GIS software to view and manipulate spatial data; however TAB files have been provided for those who do not have GIS software. To view the TAB files, you can download MapInfo ProViewer software which is a free MapInfo viewer from Pitney Bowes.

Further information