The rental listings component is based on all monitored and unique listings for the period of a calendar month. The series starts off in January 2005.
We then monitor all residential listings for each month and create three columns. 1) New listings added for the month..2) Listings withdrawn for the month and current listings as at the very end of the month.
A reconciliation is conducted with the number added, number withdrawn and the previous current listings.
All listings are taken from online monitoring of major listings sites. Only those properties with unique addresses are used. Those advertisements with no addresses are excluded from the series. Any addresses repeated between the two sites are de-duped.
Finally, only those listings that have been advertised for two weeks or more (and are still currently advertised as at the time of collation) are used.
Established Dwellings
We use the 2006 No. of total established Dwellings (as a base) by postcode as determined by the ABS census. In addition we estimate total dwellings for 2005, 2007 and 2008. We then multiply this by the percentage of renters for each postcode as also provided in the census. This provides an estimated available total stock for rent.
The numerator is then divided into the denominator, which provides a vacancy rate percentage.