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It looks from the polls that support for Scottish independence is at worst 44% and at best 49%. You might have been dismayed by the poll that reported only 44% and a wee bit excited by the 49% but it doesn’t really matter as much as the fact that support is being polled as solid from 44% up to 49%. I say this because the polls have a built in conservatism and a tendency to predict a status quo outcome. I’ll come back to why that means the real level is probably clearly above 50% for Yes.

First though, even within that 44% to 49% range, we have no idea which end of it is more likely to be the more accurate point upon which we can then add our confident if approximate supplement. Why? Well Scotland’s top psephologist said in his blog Polls Swing High, Polls Swing Low on 17th March:

‘But, of course, we always have to remember that even when there has been little or no change of opinion, polls can sometimes swing high and then swing low simply as a result of the chance variation to which all polls are subject.’

I’ll translate. He doesn’t know. They only poll about 1 000 people typically. The polls are all in that range but he has no idea what is the most accurate figure. No one does. Again, it doesn’t matter as even 44% is close enough.

Here’s the point: 14% of UK adults live in a mobile-only house with no landline and so cannot be auto-dialled by the polling companies. They are also more likely to be young or poor. We know already that support for yes is at 72% for the under 24s and at 65% for those living in the 20% most deprived areas in Scotland.

So, in landline-telephone-polls, 14% of the electorate is being missed, they are mostly young and/or poor and mostly Yes-supporters. At worst if we only took half of them to be yes-supporters, the entire 44% to 49% Yes support in the polls turns into a majority of between 51% and 63%. If we reasonably assume around 65% of them are Yes supporters. Then that adds another 2% pushing the range up to between 53% and 65% for Yes. Remember the 44% figure was a bit of an outlier. Now we’ve seen how the polls failed to predict the last Tory win, Brexit and Trump. We know the campaign has not even begun and that the last one took Yes support up nearly 20%. We know the Tories will do something stupid soon. We know the No campaign are divided and have no credible leader. We know the bookies say Yes.

https://www.ofcom.org.uk/about-ofcom/latest/media/facts

http://blog.whatscotlandthinks.org/2017/03/polls-swing-high-polls-swing-low/

http://www.ssa.natcen.ac.uk/media/38910/ssa16-2fr8m-1ndyref-2-1ndyr8f-tw0-two.pdf

http://blog.whatscotlandthinks.org/2014/09/voted-yes-voted/