From time to time I get asked about my banner header showing successive Office of Budget Responsibility (OBR) forecasts for GDP growth against actual GDP growth and, in particular, what has happened since. The OBR produces its forecasts twice a year, in March and December, and the latest one is here. However I have resisted updating my banner to date for a number of reasons:

• The statement that economic forecasts are wildly inaccurate has become a truism that, in my view, no longer needs additional evidence in support; and
• To be completely honest, once actual GDP growth started to increase (as was inevitable eventually, and particularly once the Government’s austerity boot’s grip on the economy’s neck started to weaken), the graph no longer looked quite as amusing.

However, I have recently started to question the first of these assumptions so here is an updated graph:

Notice how the point at which growth peaks and starts to fall is moving closer with each new forecast. This is as much a part of their models as putting back the upward path a quarter or two with each successive forecast was while that path was still actually falling. Be assured that the OBR will not forecast the next fall before it actually happens.

What concerns me is the forecast consensus which is starting to build around 2014-2018 of GDP growth between 2% and 3% pa (currently narrowing as a forecast to 2.5% – 2.8% pa). This is despite the OBR themselves making no more than a claim of 20% probability of growth staying in this range, as the following fan chart shows:

However I don’t see this fan chart turning up in many news reports and therefore my concern is of an election campaign fought under the illusion of a relatively benign economic future. I think it is likely to be anything but, particularly as the Government is likely to stick the boot back in post election whoever wins.

There seems to be no chance of stopping the OBR and others publishing their forecasts, too many people seem to value the power of the story-telling however implausible the plot, so the only course available seems to be to rubbish them as often as we can. That way it may just be possible, despite all the noise about predictions of economic recoveries and collapses we cannot possibly foretell being used to try and claim our political support more generally, to keep in mind that we know zero. And make better decisions as a result.