In 2007, the Australian Bureau of Statistics (ABS) introduced new methods for the estimation of net overseas migration (NOM). With the annual revisions, released in March 2009 and 2010, there were large upward revisions in the estimates of NOM and consequently the estimated resident population (ERP) in Australia for 2006-07 and 2007-08. This was due mainly to the large revision from the preliminary to a final NOM estimate, which was much greater than previous revisions. However, it was also due to the cumulative impact of only releasing the revision to quarterly NOM estimates and ERP once a year, based on a scheduled annual revision cycle.
An opportunity to help address this issue arose in 2009 when the Australian Parliament passed the Federal Financial Relations Act 2009. The new legislation changed the date required for the Australian Statistician to make the yearly determination of the population of each state and territory (as at 31 December). It changed the due date from 'before 6 June' to 'before 31 August in the following payment year'.
In consultation with major stakeholders, this legislative change enabled the ABS to provide quarterly ERP at a later date in the scheduled month of release (i.e. at the end of March, June, September and December). In turn, this enabled an additional quarter of overseas arrivals and departures data to be used allowing the methodology for preliminary NOM estimation to be improved. As a result, the ABS implemented two key changes to the methodology: changing from a 'two year ago' to a 'one year ago' propensity model; and reducing the pool of travellers using the model.
In addition, the ABS changed the current annual revision cycle for publishing final NOM to a six-monthly revision cycle. While not impacting on the difference between preliminary and final NOM estimates, this change provides for the earlier progressive release of revised ERP figures.
The improvements outlined in this chapter are designed to capture some immediate gains to NOM estimation. However, additional investigations are being undertaken by the ABS to make further gains and build upon the improvements identified in this chapter.
This chapter provides an overview of the changes undertaken to improve NOM estimation and reduce the large revisions to ERP and includes:
- a review of changes being made to the methodology for estimating preliminary NOM;
- an outline of changes to the preliminary and revision timetables;
- implementation dates and schedules; and
- discussions on future directions the ABS is examining to make further improvements.
Estimates of both the resident population (ERP) and NOM for Australia and each of the states and territories are published quarterly in Australian Demographic Statistics
(cat. no. 3101.0). The improvements outlined in this chapter were introduced from the September 2009 issue of Australian Demographic Statistics
(cat. no. 3101.0), released on the 25 March 2010.