EU Polling Update - ComRes and turnout, YouGov and education
ComRes had a new EU telephone poll in this morning's Daily Mail. Topline figures are REMAIN 52%(-1), LEAVE 41%(+3), Don't know 7%(-2). Tabs are here.
Note that this poll is now adjusted for likelihood to vote, using ComRes's turnout model based on socio-economic factors, like age and class (the changes are adjusted to reflect this). Note that adjusting turnout based on ComRes's model has marginally increased support for Remain (before the adjustment the figures would have been 51 and 41).
There's a broad assumption that differental turnout is more likely to favour Leave in the EU referendum campaign, largely based on the fact that polls normally show Leave voters claiming they are more likely to be 10/10 certain to vote, and that Leave voters are older. I'm not so sure. Self-reported likelihood is a blunt tool (people who say they are 10/10 certain to vote are not really much more likely than 8/10 or 9/10 people), and the age skew that should favour Leave in terms of turnout (older people are more likely to vote, and more Leave) will to some degree be cancelled out by the social class and educational skews that favour Remain (middle class people and graduates are more likely to vote, and more Remain).
On the subject of education, YouGov also had an interesting article up today. Like Populus and ICM they have carried out parallel telephone and online surveys, but unlike other such tests which have found a big gulf between phone and online results YouGov found results that were very similar to each other: both phone and online polls found a small lead for Leave.
This result wasn't just the weighting (even before weighting the raw sample was a lot more "leave" than the raw samples from other phone polls) suggesting it is something to do with the sampling. Obviously we can't tell for certain what the reason is - the most obvious difference is that the YouGov poll was conducted over the period of a fortnight, so was slower than most telephone polls and there was more opportunity to ring back people who were unavailable on the first call - but there could be other differences to do with quotas or the proportion of mobile calls (the YouGov poll was about a third mobile, two-thirds landline. My understanding is most phone polls are about 50/50 now, though MORI is about 20/80).
Looking at the actual demographics of the sample YouGov highlight the difference between their landline sample and the samples for the Populus paper looking at phone/online differences - specifically on education. In the Populus telephone samples between 44-46% of people had degrees, whereas the actual figure in the Census and Annual Population Survey is around 30%. The YouGov phone sample had a lower proportion of people with degrees to begin with, and weighted it to the national figure.
There is a clear correlation between education and attitudes to the EU referendum (in the YouGov polls there was a Leave lead of about 30 points among people who left school at 16 and a Remain lead of 33 points among those who were in educated beyond the age of twenty. This is partially to do with age, but it remains true even within people of the same age) so samples are too educated or not educated enough it could easily make a difference. As it is we've only got education data for the Populus polling - we don't know if there's the same skew in other phone polls, or how much of a difference it would make if corrected, but different levels of education within achieved samples is a further hypothesis that could explain that ongoing difference between phone and telephone samples for the EU referendum.
