Three major lifecycle events - births, deaths and migration - all combine to change the size, structure and distribution of Australia's population. Migration can be considered to be to or from overseas, or within Australia (internal). This paper describes a set of experimental regional internal migration estimates for Australia.
An established set of administrative data sources forms the basis for the Australian Bureau of Statistics (ABS) providing reasonably direct and regular measures of births, deaths and overseas migration for Australia. The measurement of internal migration by the ABS however relies on sources for which statistical purposes are not their primary function.
Regular estimates of interstate migration are compiled by the ABS using a statistical model based on data provided by the Australian Government Department of Human Services (from Medicare) and the Department of Defence. These sources provide good quality estimates of internal migration at the state/territory level. However, the geographic characteristics of the Medicare and Defence data - based on postcodes - have in the past been considered too incompatible with Australia's official statistical boundaries below the state/territory level to be deemed suitable for estimating internal migration on these official boundaries.
From 2012, the ABS will receive Medicare data on the new Australian Statistical Geography Standard (ASGS) regions, which will eliminate some of the issues that are present for historical data because the data will be provided on the level of geography required for output. However, the ABS currently has access to a twenty-five year time series of postcode-based Medicare data. This historical dataset is a rich source of information and it can provide an insight into past regional internal migration patterns in Australia.
This paper summarises a method to convert the historical Medicare-based internal migration data and Defence force personnel movements data from postcode regions to Australian Standard Geographical Classification (ASGC) boundaries at the Statistical Local Area (SLA) level. It discusses challenges with this approach and provides potential solutions to overcome these challenges in respect of the historical estimates. The paper also provides an opportunity to provide feedback to the ABS on these data, methods and experimental estimates. The ABS will then consider this feedback in planning any future work in respect of historical regional internal migration estimates.
To illustrate the potential of the data, this paper presents an experimental version of these regional internal migration estimates, however the ABS will continue to review the data and methods prior to any release of regional internal migration estimates.
For further information relating to regional internal migration estimates, please contact:
Regional Population Unit
Australian Bureau of Statistics
Phone: (08) 8237 7370