Australian Bureau of Statistics
Celebrating the International Year of Statistics 2013

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Changes to preliminary and revision timetables

Following the legislative changes made in 2009 and consultation with major stakeholders, the ABS now publishes quarterly ERP at the end of each scheduled month of release. This includes the quarterly release of preliminary estimates for the three components of population change: net overseas migration (NOM), net interstate migration (NIM), and natural increase (births minus deaths).

Release dates have been changed to allow for the use of additional traveller movement data in the calculation of improved preliminary NOM estimates.

Table 4.3 shows the scheduled release dates for ERP and the components of population change to be published quarterly in Australian Demographic Statistics (cat. no. 3101.0).

4.3 New scheduled release dates for Australian Demographic Statistics (cat. no. 3101.0)
	Issue (Quarter)	Release Date
	Mar 2010	29 Sep 2010
	Jun 2010	21 Dec 2010
	Sep 2010	29 Mar 2011
	Dec 2010	23 Jun 2011
	Mar 2011	29 Sep 2011
	Jun 2011	19 Dec 2011
	Sep 2011	29 Mar 2012

Six-monthly revision cycle for NOM

The quarterly fluctuations experienced in Australia's population growth and thereby ERP are currently driven by NOM. To help reduce the impact of possible large revisions to population estimates from only revising NOM estimates once a year, as was the previous practice, the ABS has consulted with major stakeholders and has changed the current annual revision cycle for publishing final NOM to a six-monthly revision cycle. Table 4.4 shows the schedule of release for NOM estimates for the September quarter 2008 to June quarter 2012.

With the implementation of the new six-monthly revision cycle for NOM it also means the annual revision for natural increase can be released six months earlier (reverting to the previous practice) to be published in the March quarter issue released in September each year of Australian Demographic Statistics (cat. no. 3101.0) (see Table 4.4).

4.4 New Release Schedule, Net overseas migration and natural increase
		Preliminary natural increase	Preliminary NOM	Revised natural increase(a)	Final NOM(b)
Reference quarter		Month of release	Month of release	Month of release	Month of release
2008
	September	Mar 2009	Mar 2009	Sep 2010	Sep 2010
	December	Jun 2009	Jun 2009	Sep 2010	Sep 2010
2009
	March	Sep 2009	Sep 2009	Sep 2010	Mar 2011
	June	Dec 2009	Dec 2009	Sep 2010	Mar 2011
	September	Mar 2010	Mar 2010	Sep 2011	Sep 2011
	December	Jun 2010	Jun 2010	Sep 2011	Sep 2011
2010
	March	Sep 2010	Sep 2010	Sep 2011	Mar 2012
	June	Dec 2010	Dec 2010	Sep 2011	Mar 2012
	September	Mar 2011	Mar 2011	Sep 2012	Sep 2012
	December	Jun 2011	Jun 2011	Sep 2012	Sep 2012
2011
	March	Sep 2011	Sep 2011	Sep 2012	Mar 2013
	June	Dec 2011	Dec 2011	Sep 2012	Mar 2013
	September	Mar 2012	Mar 2012	Sep 2013	Sep 2013
	December	Jun 2012	Jun 2012	Sep 2013	Sep 2013
2012
	March	Sep 2012	Sep 2012	Sep 2013	Mar 2014
	June	Dec 2012	Dec 2012	Sep 2013	Mar 2014
(a) The annual revision cycle for natural increase used for 2006-07 and 2007-08 had revised estimates released in the month of March, 21 months after the reference year. The new annual revision cycle for natural increase is scheduled to start from September 2010 and then each September onwards. This will be 15 months after the reference year and will be six months earlier than the previous schedule.
(b) The annual revision cycle for NOM used for 2006-07 and 2007-08 had revised estimates released in the month of March, 21 months after the reference year. A new six-monthly revision cycle is scheduled for NOM. The new quarter for release will start from September 2010 and then every six months onwards. This means the September and December quarters and therefore calendar year estimates of final NOM, will be available six months earlier than the previous schedule.

Implementation date

The improved methods for estimating preliminary NOM based on the 'one year ago' propensity model were published for the first time in ABS population estimates on 25 March 2010 in Australian Demographic Statistics, September Quarter 2009 (cat. no. 3101.0).

The improved preliminary NOM methods were applied to estimates from September quarter 2008 onwards. For September quarter 2008 to June quarter 2009, the already published preliminary NOM estimates based on the previous methods using a 'two year ago' propensity model were replaced with the improved preliminary NOM estimates. September quarter 2009 preliminary NOM estimates were based on the improved methods and published for the first time.

As part of the previous scheduled annual revision cycle, the September 2009 issue of Australian Demographic Statistics (cat. no. 3101.0) released on the 25 March 2010 also provided revised estimates for the 2007-08 financial year for births, deaths, natural increase, NOM and ERP.