This post was originally published on our new elections site, May2015.com.
The latest poll on independence is out. It puts the unionists 2 points ahead, 51 to 49 per cent. This is how the polls now look over the past two fortnight, including undecided voters.
The unionists are ahead 46 per cent to 43 per cent using a two-period moving average (and treating all pollsters equally).
But perhaps the most surprising aspect of today’s poll, published by Guardian/ICM, is the number of undecided voters they picked up. They suggest 17 per cent of voters are still unsure, with less a week to go.
The graph below shows how this compares to other polls over the past six weeks.
17 per cent seems higher than most, but the differences are all due to how the poll was conducted. The two 23 per cent ‘peaks’ in the data are both from TNS-BMRB, which conduct face-to-face polls.
ICM’s poll was conducted over the phone, whereas their previous polls, and YouGov’s, were carried out online. As YouGov’s Anthony Wells put it, there seems to be a ‘methodological difference’.