The final set of US growth figures before the presidential election were released today [2], showing that the economy grew at an annual rate of 2 per cent in the third quarter or a quarterly rate of 0.5 per cent. The Tories, unsurprisingly, are keen to point out [3] that that's a worse performance than the UK, which, as we learned [4] yesterday, grew at a quarterly rate of 1 per cent in Q3.  But they would be wise not to invite too much comparison of the UK and US economies.

First, while the US has grown by 2.3 per cent over the last year, the UK economy has failed to grow at all. As the Office for National Statistics reported yesterday [5]: "GDP in volume terms was estimated to have been flat in Q3 2012, when compared with Q3 2011".

Second, while the US economy is now 2.3 per cent above its pre-recession peak, the UK remains 3.1 per cent below. The US has grown for 13 consecutive quarters, but we've only just recovered the output lost in the double-dip recession (a fate that the US, partly thanks to a policy of stimulus, rather than austerity, avoided). As a result, while they've grown by 3.9 per cent over the last two years, we've grown by just 0.6 per cent.

Finally, since the UK Q3 figure was artificially inflated by the bounce-back from the extra bank holiday in June (responsible for around half of the 1 per cent growth) and the inclusion of the Olympic ticket sales (responsible for 0.2 per cent), it's foolish of the Treasury to cite it as proof that we're "on the right track". Indeed, as I wrote [6] yesterday, a significant number of forecasters believe it's possible or even probable that the economy will shrink in quarter four. Rather than complacently boasting about a one-off surge in growth, the Tories should be acting to prevent a triple-dip recession.