Here is the relevant table from the PBR (click on image to enlarge):
Yeah, right. In a world of over-indebtedness, zombie banks, and tax increases, that just ain't gonna happen, boys.
- The average of independent forecasts for more or less the same period (2010 to 2013) is just 2% pa - and that was collected and published by the Treasury itself (see here page 18).
- Last time we had to tackle a fiscal crisis even remotely like the current one - in the 70s - GDP growth was pretty close to zero for the following five years: in fact between 1976 Q4, when the IMF arrived, and 1981 Q1, when Geoffrey Howe finally completed the necessary fiscal consolidation, UK growth averaged just 0.4% pa.
As we've mentined before, the Treasury's own rule of thumb says that one percent off GDP increases the fiscal deficit by 0.7 percentage points of GDP. Which as things stand comes to around £10bn in cash terms.
But of course, that's cumulative. If GDP growth is 1% pa lower than HMT's forecast, by the end of 5 years, the fiscal deficit will be running £50bn higher than the Treasury forecasts. Well actually more than that, because by the end of 5 years, with all that extra borrowing, government debt will be £150bn higher than the Treasury projects. Which means interest costs will be higher. And even if we assume the government can go on borrowing at 4% (a very heroic assumption), that's another £6bn pa on the deficit - ie the 2014-15 deficit is £56bn higher.
Which means that if we take the average of independent GDP forecasts, by 2014-15 borrowing will not be £82bn as the Treasury projects, but more like £140bn - hardly any improvement at all on this year's £178bn.
And if we take our post-IMF growth experience from the 70s as a guide, borrowing in 2014-15 will be... gulp... can this be right? £228bn (equals (3.0 minus 0.4) times £56bn plus £82bn).
And you know, it could be even worse than that. Because HMT is making some fairly optimistic assumptions about the recovery of tax revenues from the finance and property sectors. Plus, it's assuming unemployment stops rising in 2011 - back in the 70s, our joyless jobless stagnation saw unemployment go on rising for nine whole years.
Right that's enough. I'm off out now to a fiscal workshop under the chairmanship of Evan Davis. Maybe he's got some answers. Or at least, a stiff drink.