Donor assumption forecast dataset explained Place Forecast Feature

Referenced by 2 other explainers

The donor assumption forecast dataset is an axiomatic dataset. It is a council dataset that banks demographic behaviour captured from a donor area: fertility, mortality and migration rates by age and sex, plus the age and sex mix of in-migrants.

Each behaviour is held at its own latest estimated year, which is why the columns on the detail page carry different years.

A recipient small area names one of these donations on a Donor row in the housing and dwelling assumptions. An area does this when it holds too few people per age and sex cell for its own rates to be stable. Each donated rate takes over as the area's own figures for it run out. Fertility rates take over in the year after the latest estimated births, and mortality rates in the year after the latest estimated deaths. The ABS publishes births and deaths at different times, so these can start a year apart, and out-migration rates take over with whichever comes first. In-migration rates apply from the first year past the ABS component totals. The age and sex mix of in-migrants applies earlier, in every year after the latest Census. A Donor row can name a later start year, for an area whose population only changes once new housing arrives. The area then keeps its own fertility, mortality and migration rates and its own in-migrant mix until that year, and the donated ones apply from it. The dwellings and the number of people moving in still follow the housing and dwelling assumptions. Where the ABS has already published a year's component totals and estimated resident population, projected in-migration and out-migration are still scaled to those totals, and migration balancing still matches them to that population.