“There is a small productivity effect [in the OBR’s Brexit forecasts] but it is tiny compared to the scale of the change that we have made on this occasion, and it is tiny compared to the scale of the shortfall in productivity relative to a continuation of pre-crisis trend,” said Sir Charlie Bean from the OBR. “I think it is very important to realise that the big issue economically for the British economy is productivity, it is not coming from the Brexit assumptions or anything like that. “That is the really big challenge, if we could do something to address that successfully, it would completely swamp the Brexit consequences, whatever they are. The scale could not be big enough compared to the productivity slowdown.” Mr Chote noted that poor productivity growth had afflicted developed economies across the world, making it hard to pin down precisely why growth has been so slow and how to fix it. “You can overdo it by focusing on particularly UK-specific explanations of this, there is a lot more going on,” he said.
The expected €45bn ($53bn) to €55bn cost to the UK of leaving the EU is relatively insignificant compared with the "total effect of Brexit" and the UK's dwindling productivity, said Robert Chote, the head of the Office for Budget Responsibility. He urged MPs to look at the wider picture and not dwell on the exact figure of the so-called divorce bill. Chote said the effects of Brexit would be less important than fixing the UK's chronically low productivity.