Referenced by 17 other explainers
Downscaling moves ABS marker counts from the smallest area ABS publishes down to a small area. Place Forecast uses its general tessellation method to do this. The weight is occupied private dwellings (OPD) in each mesh block — the homes ABS counts as people's usual place of residence.
Most markers downscale from the ABS Statistical Area Level 1 (SA1) figure. Same-sex couples is the one marker that downscales from the Statistical Area Level 2 (SA2) figure, because ABS does not publish couple-type counts at SA1.
OPD is a clean weight for markers that count households or families. For markers that count people, it rests on the rule that more homes tend to mean more residents in an area.
It has a known limit. Some mesh blocks hold residents in non-private dwellings — prisons, aged-care homes, defence bases, on-campus student housing. These mesh blocks have no occupied private dwellings, so our method gives them no share of the SA-level count. Their residents sit in the wider-area total, but the chart can't show them at a finer level. The same effect can mute the share of a mesh block where a retirement village, a refuge, or a workers' camp sits.
Downscaling also spreads out small groups that cluster in a few streets. Say a group shares a language, place of birth, or family type, but lives in just two streets. The chart spreads that group across the wider area. It shows the wider area's pattern, not where the group really lives. ABS perturbation adds a small shift on top.
So the figures for very small areas are an estimate, not a direct ABS count. Per-group LGA totals are still fixed to ABS through LGA anchoring.
For service choices about one community, read small-area figures as patterns, not exact counts. Check them with community organisations before drawing strong claims.