Interstate migration is the movement of people from one state or territory of usual residence to another state or territory of usual residence. It is an important determinant of the population growth and distribution across Australia. This chapter examines interstate migration estimates as used in calculating the estimated resident population (ERP) of Australia's states and territories.
There is no direct measure of interstate migration within Australia on a quarterly basis, unlike that of natural increase (births minus deaths) and net overseas migration (NOM - NOM arrivals minus NOM departures). Medicare Australia data, which supplies change of address information, is the most effective source currently available from a range of potential sources of administrative data (see paragraph 58 of the Explanatory Notes). Therefore, estimates of interstate migration are modelled using Medicare change of address data. The model is reviewed and updated every five years using data from the latest Census of Population and Housing. For more information, see Information Paper: Review of Interstate Migration Method, March 2009 (cat. no. 3106.0.55.001).
It is estimated that 359,900 people moved interstate during 2008-09. It is important to note that the total number of persons who moved is less than this, after return and repeat movements are taken into account. In addition, for each flow from one state or territory to another, there is a counter flow.
6.1 Gross Interstate Migration, Australia