Our latest estimate suggests that the growth rate in the three months ending in December is 0.5% after 0.7% in the three months to September. This is a welcome moderation from a growth rate that has been persistently above trend for the past two years. As in our October forecast, we expect GDP growth to be significantly below trend this year. Our track record in producing early estimates of GDP suggests that our projection for the most recent three-month period has a standard error of 0.14% point when compared to the first estimate produced by the Office for National Statistics. This comparison can be made only for complete calendar quarters. Outside calendar quarters the figures are less reliable than this.
A paper describing the methodology used to produce the data was published in the February 2005 volume of the Economic Journal. From April until October 2006 our estimates were computed using the Index of Services published by ONS. However this monthly series shows considerable volatility which has caused us some problems in estimating GDP. From our November 2006 press release we have therefore reverted to using a model of private services output based on indicator variables. This means that, while all our figures for calendar quarters are fully coherent with ONS data, our estimates of monthly private service output are not. The series can be thought of as indicating the underlying value of the ONS series.
For more information please telephone Simon Kirby on 020 7654 1916.