Well, I'm not an expert on the Treasury, but this is what Kwasi Kwarteng said today
"Another Tory, Kwasi Kwarteng dismissed the document as 'intellectually dishonest'.
'I think these figures are absurd, frankly,' he told the BBC's Daily Politics. 'The Treasury were the same people who said at the beginning of the last parliament that we would have eliminated the deficit by 2015. The deficit has not been eliminated.
'The Treasury did not predict the 2008 credit crunch, neither did they predict the Greek blowout and so, for a bunch of officials and economists to say they can describe within a pound what the state of the British economy and people's economic wellbeing will be in 2030, 14 years' time, is simply absurd.'
I think Kwasi was being a little unfair because they probably did predict the MPs' 11% pay rise.