The last three polls, from ICM, Populus and ComRes, have shown slight variation but have all been reporting the same trend: Labour collapsing further and the Liberal Democrats benefitting. The Sunday Times’s YouGov poll however paints a far more static picture. The topline figures, with changes from YouGov’s last poll, are CON 44%(+1), 32%(nc), 14%(-2).

So where ICM, Populus and ComRes have Labour shifts to the Lib Dems, YouGov have pretty much no change (the 2 point drop in the Lib Dems would probably mean nothing anyway, prior to their last poll YouGov had the Lib Dems at 14%-15% for 10 polls in a row).

This obviously begs the question of who is right. Are the Lib Dems up or not? Well, some pollsters are more volatile than others, but ICM and YouGov both produce very consistent figures. We are used to ICM and YouGov showing divergent Lib Dem figures – there are various possible reasons for this but one can normally expect a couple of points difference in their reported level of support. They do tend to show the same sort of trends though – when ICM show the Lib Dems high by ICM’s standards, YouGov show them high by YouGov’s standards (and vice-versa). Besides, eight points is well beyond the normal difference between the two companies.

Normally I would be very suspicious of any change that doesn’t have an obvious explanation – public opinion doesn’t magically move by itself, people react to events. If a party jumps up by a third in the polls when they haven’t really done much or got significantly more publicity than usual, it should ring alarm bells. A six point change in the polls is the sort of thing that normally only happens in either rogue polls, or in response to something big.

For that reason, if it was just the two polls my expectation would be that the ICM poll would turn out to be a freak result, and the YouGov one correct…but in this case the trend in ICM is supported by similar findings from ComRes and Populus. It might not have an obvious explanation, but as I said in a comment on a previous post, perhaps it’s just that Labour’s continuing collapse in support was starting to eat into those people who would never consider voting Tory and see the Lib Dems as their natural alternative. Looking at the details of ICM and ComRes part of what also appears to have happened in both of them is that people who voted Lib Dem in 2005 are much more likely to vote Lib Dem now than a month ago (Lib Dem “voter retention” has gone up from 64% to 72% in ICM, 69% to 84% in ComRes).

Of course, it may just as well turn out that the Lib Dem bounce proves illusionary and the YouGov poll is shown to be right. We won’t really know for sure until we see what happens in the next ICM (should be this week in the Guardian) and YouGov (probably in the Telegraph at the end of the month) polls. We could even, theoretically, find that the difference persists for some methodological reason… but I doubt it very much, if it does we’ll worry about it when it happens!

52 Responses to “A contrasting picture from YouGov”

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  1. On the point about by-election results, I’ve looked at the site Anthony posted and the results seem to back up the polls in my view.

    Tories holding their own from an elevated starting point and the Libs nicking a few from Labour. Fits the polling narrative perfectly or am I missing something?

  2. Labour are doing very well holding vital local council seats. Unfortunately their paymasters the unions appear to have lost patience with Gordon Brown.

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