Annual revisions and methodological changes have resulted in the Office for National Statistics cutting its estimate of the fall in GDP during the 2008-09 recession (i.e. between the first quarter of 2008 and the second quarter of 2009) from 7.1% to 6.3%. Embarrassingly, this almost exactly reverses an upward revision to the peak-to-trough decline – from 6.4% to 7.1% – in the last (delayed) annual update in October 2011.

A 6.3% drop still implies that the 2008-09 recession was deeper than the 1979-81 downturn, when GDP fell by 5.9% – see chart. Likely further substantial revisions in future years, however, could change this story.

GDP in the first quarter of 2012 was still 3.9% below the pre-recession peak – a much weaker performance than after previous recessions. Data for 2011 and beyond, however, have not been subject to the annual supply-and-use balancing process so are especially susceptible to future revision.

The current GDP recovery has been held back by falling North Sea oil and gas production. Interestingly, GDP excluding oil and gas in the third quarter of 2011 was at a similar level, relative to the previous peak, as overall GDP at the same stage of the 1979-81 recession / recovery cycle. (GDP ex. oil and gas figures are unavailable for the earlier period.) The negative divergence in the latest two quarters may reflect the impact of the Eurozone crisis – both directly on exports and, more importantly, indirectly on credit conditions and confidence.