§ Lord Taylor of Warwickasked Her Majesty's Government:
Why the Office for National Statistics understated Britain's latest national accounts by £800 million. [HL5079]
§ Lord McIntosh of HaringeyThe information requested falls within the responsibility of the National Statistician who has been asked to reply.
Letter from the National Statistician, Mr Len Cook, to Lord Taylor of Warwick, dated 4 October 2003.
As National Statistician I have been asked to reply to your recent question on Britain's National Accounts. (HL5079).
I have assumed that your question refers to the estimate of gross domestic product (GDP) growth during the second quarter of 2003, which was revised from 0.3% to 0.6% in September 2003. This revision represents economic activity of approximately £800 million.
It is standard statistical procedure to revise previously published figures once new evidence becomes available. Revisions mainly arise from the availability of more rich and detailed information, as in this case, where results from a full survey of the construction industry gave a markedly different estimate of activity in this sector than had been provided by earlier model-based calculations, and early returns from the survey.
The magnitude of the revision to GDP was outside the range that is usually expected at this time, and arose from an unusually large revision to the estimate of activity in a single sector of the economy. The Office for National Statistics (ONS) is investigating whether this revision reflects ongoing difficulties in measuring a sector which is known to be volatile, and whether the sector measure itself meets our current expectations. We are also continually updating methods and adapting to shifts in the economic base of the United Kingdom.
Further information regarding this revision to GDP appears in the Quarterly National Accounts Briefing Note which is available on the National Statistics website at: http://www.statistics.gov.uk/ pdfdir/qnabrief0903.pdf.
Whenever revisions are made, we publish them in an honest and transparent manner, under the terms of the National Statistics Code of Practice. Furthermore, we periodically publish analyses of the revisions made to the GDP figures, so that users can assess the nature and magnitude of the changes that have been made.