Referenced by 14 other explainers
Census count is the unadjusted number of people the ABS counted at a place during the Census, recorded at their place of usual residence. Place Forecast uses Census counts as the source for Census-derived markers — Household type, Family blending, Marital status, Social marital status, and others.
Census counts are different from the Estimated Resident Population (ERP) that you see on the population pages. ERP is the ABS's official population estimate. It is built from the Census usual-residence count and then adjusted in three ways:
Net undercount adjustment. The ABS runs a Post Enumeration Survey after every Census to estimate how many people the count missed. ERP scales the Census count up to cover that undercount.
Residents temporarily overseas. ERP adds back people who usually live in the area but were overseas on Census night. The Census count leaves them out.
Reference date. ERP is published at 30 June. The 2021 Census was run on 10 August 2021. The ABS shifts the Census count back to 30 June 2021 by netting out the births, deaths, and migration in those weeks.
For the same area and the same year, ERP is in almost all cases at least as large as the Census usual-residence count, and usually a little larger. The gap is small for most LGAs. It is often a few hundred to a few thousand people, based on the area's undercount and overseas-resident profile.
When you see a smaller total on a Census-derived marker than on the population pages, that is by design. It is not a data error. The marker shows an unadjusted Census count. The population pages show ERP.