Household projections are published by the Australian Bureau of Statistics (ABS). Australian household projections are not predictions or forecasts, but are illustrations of the change in the numbers of households that would occur if assumptions about future trends in living arrangements were to occur. The projections are derived using propensities from the Census of Population and Housing for persons to be in different living arrangements. Trends observed in the propensities over the last four Censuses are assumed to continue into the future, and applied to a projected population. Numbers of families are then derived from the projected living arrangements of the population, and numbers of households are derived from the projected numbers of families.

Three projection series are presented in Household projections, and each series reflects a different assumption about future change in peoples' living arrangements. Living arrangement information from the last four Censuses (2001, 2006, 2011, 2016) are used to set the assumptions, and their assumptions are as follows:

Series I assumes no change in living arrangement proportions, and living arrangement rates for 2016 remain constant to 2041. Series II assumes a smaller change in living arrangement proportions; the trend observed from 2001 to 2016 continues at the full rate of change for five years (to 2021), then half the rate for five years (to 2026) then one-quarter the rate for five years (to 2031), and then remains constant (to 2041). Series III assumes a larger change in living arrangement proportions; the trend observed from 2001 to 2016 continues at the full rate of change all the way until 2041.

See ABS 3236.0 - Household and Family Projections, Australia, 2016 to 2041 (https://www.abs.gov.au/ausstats/[email protected]/mf/3236.0) for further information, including in-depth commentary and analysis, in particular, the source data Quality Declaration. Source reference Data Cubes, Projected number of households, Household type - 2016 to 2041, tables 1.1 to 1.23.