It would be wise to view a new poll with cautionby Peter Kellner / January 8, 2018 / Leave a comment
Just before Christmas, I warned Remainers not to get too excited about a poll showing a ten point lead for staying in the EU. The opposite now applies. In his latest column for the Sunday Times, Dominic Lawson reports a YouGov poll showing a Leave lead widening from two to nine points in the past three months. Once again, I doubt whether there has been any real shift in public opinion.
The poll Lawson cites was one of YouGov’s Eurotracker series. It is conducted monthly, but this particular question is asked less frequently. This is how it is worded:
At this point would you prefer that Britain stays in or leaves the European Union?
In early October, it found a 46-44 per cent margin in favour of leaving; in the latest survey, conducted just before Christmas, the Leave advantage had widened to 48-39 per cent.
It is just possible that the shift is the result of sampling fluctuation. However, that is unlikely to be the whole explanation: a five point drop in the Remain percentage looks too large.
There is, though, another explanation. It concerns polling methods rather than shifts in public attitudes. A new question was added to the December poll that was not asked in October: