The projections in this publication provide an indication of numbers of households and families in Australia between 2006 and 2031, based on assumptions about future living arrangements of the population. They are illustrations of the change in numbers of households and families, and changes in the distribution of living arrangement types, which would occur if certain assumptions about future living arrangements were realised.
It is important to note that the projections are not predictions or forecasts. Factors such as changing levels of household and family formation and dissolution (including marriage and divorce), economic conditions, employment, housing affordability and interest rates may all affect future household and family formation, but are not explicitly taken into account in these projections. There is no certainty that any of the assumptions will be realised.
The projections use various assumptions about rates of change in the likelihood of persons to be living in certain living arrangements. Three assumptions about the rate of change in living arrangements have been used to produce three series of household, family and living arrangement projections. These are referred to as Series I, II and III.
In Series I, living arrangement patterns remain the same as in 2006, therefore changes in numbers of households, families and persons in different living arrangement types are due solely to changes in the size and age/sex structure of the projected population. Series II and III incorporate, to a lesser or greater degree, assumptions about changes in the likelihood of being in particular living arrangements (see Chapter 2 - Assumptions for more information).
The base population used for the projections is the 30 June 2006 estimate of 20.7 million people, disaggregated by living arrangement type as determined using 2006 Census information. The Series B population projection from Population Projections, Australia, 2006 to 2101 (cat. no. 3222.0) provides the underlying population numbers on which the household projections are developed. Series B is one of a range of future possible scenarios for population growth (see Chapter 2 - Assumptions and Chapter 5 - What If...? for more information).
Changes in population over time are commonly discussed in terms of average annual growth rates. In this publication, however, changes are for the most part presented as percentage increases or decreases over the entire 25-year period (from 2006 to 2031), in order to make differences between projected numbers (of households, families and people in different living arrangements) more discernible.