AN IMPROVED METHOD FOR CALCULATING NET OVERSEAS MIGRATION
The ABS has been developing improved methods for estimating net overseas migration (NOM).
NOM estimates are an essential component of population change and are used for producing estimated resident population (ERP) data. There are two key changes to the NOM methodology:
- Firstly, the shift from a movements-based approach to a traveller-based approach. Previously, NOM estimates were based on counts of overseas movements that were synthesised and adjusted to represent individual travellers. Under the new system, all estimation is based on counts of actual individual travellers and their travel histories.
- Second, the introduction of a 12/16 month rule. Previously, in order to be included as a usual resident of Australia, a person was required to be continuously resident for a period of 12 months. Persons are now included in the resident population if they are in Australia for a total of 12 months or more over a 16 month period.
There will be a break in the NOM time series as a result of these changes. The new method was applied to ERP from the September quarter 2006 and the first estimates were released in Australian Demographic Statistics, Dec 2006
(cat. no. 3101.0) on 5 Jun 2007.
The Information Paper: Statistical Implications of Improved Methods for Estimating Net Overseas Migration, Australia, 2007
(cat. no. 3107.0.55.005) outlines the methodological changes and contains analysis of the statistical impacts on experimental NOM estimates for the period December 2003 to June 2006.