EU referendum: Why the use of data by EU campaign groups should be taken with a tablespoon of salt

But for Simon Tilford, deputy director at the Centre for European Reform, the numbers aren’t helpful at all: "The whole idea of putting concrete figures on this is nonsense. It is impossible to be anywhere near as precise as the In and Out camps are attempting to be on this question."

To get a real idea of what’s going on, one has to look at what information campaigns actually base their assumptions on because if one assumes, as say the out camp does, that EU membership is a constraint on British trade, then leaving the EU, by that reasoning, will boost British trade. So, as Tilford states: "One has to scrutinise their assumption that EU membership is a constraint on trade."

It’s not all that different to the political campaigns in the build up to the General Election, Tilford says. "We see that if one looks at the manifestos of the General Election what both major parties in the UK argue and how they site evidence is heavily influenced by their own assumptions and own interests."
"The campaign on this is no different from any other political campaign."