These spreadsheets contain revised data for some of the chain volume measures series released in 8755.0 Construction Work Done, Australia, Preliminary.
ENGINEERING CONSTRUCTION ACTIVITY, AUSTRALIA, DECEMBER QTR 2007 (cat. no. 8762.0)
CHANGES IN THIS ISSUE
This release has used ARIMA modelling where appropriate for individual time series. The revision properties of the seasonally adjusted and trend estimates can be improved by the use of autoregressive integrated moving average (ARIMA) modelling. ARIMA modelling relies on the characteristics of the series being analysed to project future period data. The projected values are temporary, intermediate values, that are only used internally to improve the estimation of the seasonal factors. The projected data do not affect the original estimates and are discarded at the end of the seasonal adjustment process. The ARIMA model is assessed as part of the annual reanalysis and following the
2008 annual reanalysis 58% of the applicable Engineering Construction Work Done series in 8762.0 will use an ARIMA model. For more information on the details of ARIMA modelling see feature article: Use of ARIMA modelling to reduce revisions in the October 2004 issue of Australian Economic Indicators (cat. no. 1350.0).
SIGNIFICANT REVISIONS THIS QUARTER
Compared with the current price original terms estimates published in the previous issue of this publication:
- The June quarter estimates have been revised downwards by $153.7m for work commenced, downwards by $166.4m for work done, and upwards $12.6m for work yet to be done. These revisions occurred predominantly in 'Private for Private' 'oil, gas and other hydrocarbons' in Western Australia.