Counting Moves

Amidst the commentary on the recent population release by the Australian Bureau of Statistics (ABS), one item that was missed was the announcement that the ABS had updated its methodology for estimating net interstate migration (NIM); a crucial input into how we understand population change and forecast future housing need.

The revised approach has led to notable differences in population growth across the states, highlighting the importance of accurate, contemporary data when assessing housing demand.

Why the Methodology Changed

The ABS’s former approach leaned heavily on Medicare address updates, which had limitations. Not everyone reports their moves promptly, and temporary relocations were often missed. In response, the ABS has enhanced its method by drawing from a wider set of administrative datasets, such as enrolment and taxation records, to build a more accurate and responsive view of how people move between states.

This new approach better reflects modern mobility patterns, particularly in the post-COVID era when remote work, lifestyle changes, and housing affordability have all shifted how Australians choose where to live.

Full details of the methodology revision are available here.

What the New Estimates Tell Us

The table below shows how much interstate migration figures have changed across the states for the three years to September 2024. Some highlights:

• Victoria’s net loss is much larger than previously thought, revised down by 26,096 people to –41,981. This reflects a more pronounced outflow than earlier estimates suggested.

• Queensland’s gain has been revised down by nearly 13,000, from 116,659 to 103,763, still the largest net recipient but with slightly less momentum.

• New South Wales lost fewer people than initially thought, with a positive revision of 13,856, bringing its net loss to 96,171.

• South Australia flipped from a net loss to a net gain, with a revision of over 4,300 people, highlighting growing population stability or attraction.

• Western Australia’s net inflows were underestimated, now adjusted up by over 12,000 people to 45,335.

• Tasmania’s net outflow was revised upward slightly (from 5,685 to 6,860), while the ACT and NT also saw positive revisions, with each gaining almost 5,000 more people than initially reported.

From People to Properties: The Household Impact

Revisions to population estimates naturally flow through to estimates of household formation, and by extension, housing demand. Notably, some of these revisions further underscore the trends that we are seeing in each of the states’ respective capital city housing markets.

Based on indicative numbers of persons per household:

• Victoria now shows nearly 10,000 fewer households than previously estimated, equivalent to lowered household formation of just over 3,000 households per year over three years, which is also likely to be a contributing factor to the post-COVID underperformance of the Melbourne housing market.

• Queensland’s revised gain still supports high demand, but a downward adjustment of 4,800 households slightly eases the pressure.

• New South Wales’ upward revision means 5,200 more households, or nearly 1,600 more per year, important context for a housing market that continues to see price resilience despite higher interest rates.

• The uplift in the net outflow from Tasmania is highlighted in the continued weakness in Hobart’s residential market.

• Meanwhile, the upward revisions to net interstate migration in SA, WA, NT, and ACT all suggest stronger household demand than originally anticipated, which has translated into the continued robustness of the Adelaide and Perth housing markets in particular.

What It Means for Future Projections

These updates carry implications for population forecasting.

State governments, infrastructure agencies, and private-sector forecasters rely on accurate NIM estimates to model how and where people will live in the years ahead. A change of 5,000–10,000 people here or there may not sound like much, but it can have implications for local vacancy rates and the housing balance from year to year. If a change in trends persists and compounds over a number of years, then there are implications for:

• Land supply planning

• Infrastructure delivery timelines

• School, hospital, and transport capacity assessments

• Investor confidence in local housing markets

With a more robust and nuanced evidence base, future population projections, and the housing demand forecasts that flow from them, will be better targeted and more responsive to real-world behaviour.

 Planning with Precision

In a time of housing undersupply, affordability concerns, and demographic flux, it is critical that our forecasts are as accurate and up-to-date as possible. The ABS's revised migration estimates offer just that, a clearer picture of how Australians are moving, and how those moves can translate into housing demand.

Whether you are in planning, development, or policy, this update is a reminder of how dynamic population data is, and how important it is to ground your decisions in the most up-to-date evidence available.

If you need further insight into the ABS revisions net interstate migration and the implications to population growth across the states, get in touch with Angie Zigomanis at [email protected] or Rob Burgess at [email protected]