The European referendum question

I've been on holiday for the last week, but hopefully haven't missed too much polling in the August after a general election! One thing that did happen was the Electoral Commission recommending (and the government accepting) a change in the wording of the EU referendum, from a YES/NO question to a REMAIN/LEAVE question. This raises the question of whether or not the wording makes a difference.

At the end of May ICM ran a split sample experiment, asking the then Yes/No version of the question and the remain/leave question that the Electoral Commission ended up recommending. On the Yes/No wording the result was YES 47%, NO 33%, DK 20%; on the Remain/Leave wording the result was YES 43%, NO 35%, DK 22%. Results are here.

ComRes ran a similar experiment at the same time, they asked the then Yes/No version of the question, and a more general question on whether people would vote to stay or leave in a referendum (it didn't use the exact wording the Electoral Commission have now recommended). On the Yes/No wording the result was YES 58%, NO 31%, DK 11%. On the Stay/Leave question the result was STAY 51%, LEAVE 33%, DK 16%. Results are here.

YouGov haven't done a split sample, but since the general election they have asked the question in two different ways - one asking the old Yes/No referendum question, and one asking if people would like Britain to remain or leave the European Union. Using the Yes/No referendum question they have found an average YES lead of 8 points. Using a question asking if people would vote for Britain to remain or stay, they have found an average REMAIN lead of 6 points (figures are here, here and here)

The scale of the difference varies between 2 and 9 points and only the ICM poll used the actual question wording. However, the general trend is clear, a remain/leave question seems to produce a smaller pro-EU lead than a yes/no question.

However, what difference the wording makes in an opinion poll is not necessarily the same question as what difference the wording makes in a referendum. An opinion poll is getting someone's instant reaction having bombarded them with a question they may not have had a firm opinion upon until you asked. A referendum takes place after several weeks campaigning on the pros and cons on each side of the argument and what the implications and consequences of voting Yes or No (or Stay or Leave) might be. I suspect in a referendum, as opposed to an opinion poll, there is very little real difference between Yes/No and Remain/Leave.