Webinar: Improving ABS estimates of Australia’s interstate migration

Abstract:

Interstate migration is a key component of estimating state-level population change in Australia, alongside natural increase and overseas migration. Because it cannot be directly measured, the Australian Bureau of Statistics (ABS) estimates interstate migration using aggregated Medicare change-of-address data, calibrated every five years with Census internal migration data.

Population estimates from the 2021 Census revealed larger-than-usual inaccuracies for some states and territories, raising concerns about the ABS’s reliance on Medicare data. In response, ABS Demography undertook a comprehensive review of its estimation approach, exploring alternative administrative sources to improve accuracy.

As a result, the ABS updated its interstate migration model by relaxing previous restrictions on Medicare data and incorporating administrative data from the Australian Taxation Office. Following extensive stakeholder engagement, including at the 2024 Australian Population Association conference, the revised method was implemented in mid-2025 and applied retrospectively back to 2021, with population estimates updated accordingly.

This presentation will detail the new estimation methodology and present the updated interstate migration series, including comparisons with the previous approach for this crucial demographic measure.

Bio:

 Andrew is a demographer at the Australian Bureau of Statistics and has worked in ABS Demography for over 30 years. Andrew’s role over most of this time has related to preparing Australia’s official estimates of population, including internal migration data, at national, state/territory and sub-state geographies.