As people have reported and grumbled, there is no proper exit poll tonight for the Scottish referendum (the defining feature of an exit poll is that it’s done outside actual polling stations as people exit. They are very expensive, and no one commissioned one!). We are hence going to have to wait for the actual results.

The only 10pm polling news we have is that YouGov did a recontact of the people who took part in their final poll during the day today to check for any late swing – amongst those people they did find some movement from YES to NO since the final polling, producing a final YouGov prediction of YES 46%, NO 54% (details are here). Lord Ashcroft also apparently did some polling during the day asking about people’s reasons for voting how they did – those results will be out tomorrow.

Given we aren’t likely to have any proper result for six or seven hours I’m going to catch some sleep and then wake up for some real results, but feel free to discuss the early results as they come in here.

It’s been a long journey, but we’ve finally arrived at the eve-of-referendum polls. For a lot of the Scottish referendum campaign the discussion about polls was one of right or wrong – we had lots of polls showing the same trend (flatlining!), but showing different absolute figures. Companies like MORI, TNS and YouGov were showing big NO leads; companies like Panelbase and Survation were showing a tight race. Then we had a period of some companies showing a strong movement towards YES, some not, and we have ended up with everyone showing much the same figures (what was the true picture earlier in the campaign we will never know for sure – by definition you can check eve-of-election results against reality, but never mid-term ones). With one MORI poll still to come, here are the YES shares in the latest polls from each company (taking the online and telephone methodologies seperately for those companies who have done both):

Ipsos MORI (phone) 49%
ICM (phone) 49%
TNS (face to face) 49%
YouGov (online) 48%
Panelbase (online) 48%
ICM (online) 48%
Opinium (online) 48%
Survation (online) 48%
Survation (phone) 47%%

Essentially everyone is predicting the same result, the margin of error on most of the polls is around plus/minus 3%, every poll is within two percentage points of the others. This isn’t going to be a case of individual pollsters getting it right or wrong, they’ll either all be around about right or all be horribly out.

There’s a temptation when the polls are like this to say YES and NO are within the margin of error, that it’s “too close to call”. It doesn’t really work like that – these polls are showing NO ahead. The margin of error is on each individual poll, and it’s equally likely to happen in both directions. Hence if the “true” balance of public opinion in Scotland was 50/50 we’d expect to see a random scattering of results around that point, some polls showing yes, some polls showing no. We’re not seeing that. We’re seeing polls randomly scattered around the 48/52 mark, suggesting that’s most likely where public opinion is – a very small lead for the NO campaign.

It’s possible there will be a very late swing, that people will have changed their minds in the last few hours or in the polling station itself. In most polls there really aren’t that many don’t knows left to make their minds up though.

The alternative route to an upset is if the polls are wrong, if there is some systemic issue above and beyond normal random sampling error that affects polls from all the companies. I wrote yesterday about what the potential risks are – the main challenges in my view are first whether people who are on the fringes of society and normally play little part in politics don’t get picked up in polls but do vote; and secondly whether there has been an issue of differential response rate, have the obviously more enthusiastic yes voters been more willing to take part in polling that no voters are?

Personally I’m a little more worried about the latter – I think there’s more chance of the polls ending up underestimating the NO vote than the YES vote, but there comes a time when you just have to trust the data. The polls say the result will be around about YES 48%, NO 52%. We will see on Friday morning.