GDP is one of the most closely watched and politically important economic statistics, as the fuss over Britain’s first-quarter growth during the election campaign showed. So it’s interesting to note that British GDP figures tend to be the most heavily revised of all G7 countries’ figures, says Peter Spence in The Daily Telegraph.
The Office for National Statistics comes up with a preliminary figure earlier than most – often within a month – and it only uses around 40% of the data that goes into the final estimate. So perhaps it’s no surprise that Michael Saunders of Citi, examining GDP data from 1999 to 2012, has found that on average, the year-on-year figure for the UK ends up 0.5% higher than the first estimate would suggest. So a 2.4% annual pace is typically ultimately revised to 2.9%. The revisions are concentrated in the first quarter, when they are around twice as big as in the other three-month periods.