There have been three polls over the last week – in the Sunday papers there were polls from ComRes and Opinium, the regular YouGov poll for the Times last week. Voting intention figures were:

Opinium – CON 37%, LAB 25%, LDEM 16%, BREX 13%, GRN 2% (tabs)
ComRes – CON 28%, LAB 27%, LDEM 20%, BREX 13%, GRN 5% (tabs)
YouGov – CON 32%, LAB 23%, LDEM 19%, BREX 14%, GRN 7% (tabs)

There isn’t really a consistent trend to report here – YouGov and ComRes have the Conservatives declining a little from the peak of the Johnson honeymoon, but Opinium show them continuing to increase in support. My view remains that voting intention probably isn’t a particularly useful measure to look at when we know political events are looming that are likely to have a huge impact. Whatever the position is now, it is likely to be transformed by whether or not we end up leaving the European Union next month, on what terms and under what circumstances.

What did receive some comment was the sheer contrast between the reported leads, particularly because the ComRes (1 point Tory lead) and Opinium (12 point Tory lead) were published on the same day.

Mark Pickup, Will Jennings and Rob Ford wrote a good article earlier this month looking at the house effects of different pollsters. As you may expect if you’ve been watching recent polls, ComRes tend to show some of the largest Labour leads, YouGov some of the biggest Tory leads. Compared to the industry average Opinium actually tend to be slightly better for Labour and slightly worse for the Tories, though I suspect that may be changing: “House effects” for pollsters are not set in stone and can change over time, partly because pollsters change methods, partly because the impact of methodological differences change over time.

What that doesn’t tell us why there is a difference. I saw various people pointing at the issue of turnout, and how pollsters model likelihood to vote. I would urge some caution there – in the 2017 election, most of the difference between polls was indeed down to how polling companies predicted likelihood to vote, and this was the biggest cause of polling error. However when those new turnout models backfired and went wrong, polling companies dropped them. There are no longer any companies using demographic based turnout models that have a huge impact on voting intention figures and weight down young people. These days almost everyone has gone back to basing their turnout models primarily on how likely respondents themselves say they are to vote, a filter that typically only has a modest impact. It may be one factor, but it certainly wasn’t the cause of the difference between ComRes and Opinium.

While polling companies don’t have radically different turnout models, it is true to say (as Harry does here) that ComRes tends to imply a higher level of turnout among young people that Opinium. One thing that is contributing to that in the latest poll is that Opinium ask respondents if they are registered to vote, and only include those people who are, reducing the proportion of young people in their final figures. I expect, however, that some of it is also down to the respondents themselves, and how representative they are – in other words, because of the sample and weights ComRes may simply have young people who say they are more likely to vote than the young people Opinium have.

As regular readers will know, one important difference between polling companies at the moment appears to be the treatment of past vote weighting, and how polling companies account for false recall. Every polling company except for Ipsos MORI and NCPolitics use past vote in their weighting scheme. We know how Britain actually voted at the last election (CON 43%, LAB 41%, LDEM 8%), so a properly representative sample should have, among those people who voted, 43% people who voted Tory, 41% people who voted Labour, 8% who voted Lib Dem. If a polling company finds their sample has, for example, too many people who voted Tory at the previous election, they can weight those people down to make it representative. This is simple enough, apart from the fact that people are not necessarily very good at accurately reporting how they voted. Over time their answers diverge from reality – people who didn’t vote claim they did, people forget, people say they voted for the party they wish they’d voted for, and so on. We know this for certain because of panel studies – experiments where pollsters ask people how they voted after an election, record it, then go back and ask the same people a few years later and see if their answers have changed.

Currently it appears that people are becoming less likely to remember (or report) having voted Labour in 2017. There’s an example that YouGov ran recently here. YouGov took a sample of people whose votes they had recorded in 2017 and asked them again how they had voted. In 2017 41% of those people told YouGov’s they’d voted Labour, when re-asked in 2019 only 33% of them said they had voted Labour. This causes a big problem for past vote weighting, how can you weight by it, if people don’t report it accurately? If a fifth of your Labour voters do not accurately report that they voted Labour and the pollster weights the remaining Labour voters up to the “correct” level they would end up with too many past Labour voters, as they’d have 41% past Labour voters who admitted it, plus an unknown amount of past Labour voters who did not.

There are several ways of addressing this issue. One is for polling companies to collect the data on how their panellists voted as soon as possible after the election, while it is fresh in their minds, and then use that contemporaneous data to weight future polls by. This is the approach YouGov and Opinium use. The other approach is to try and estimate the level of false recall and adjust for it – this is what Kantar have done, instead of weighting to the actual vote shares in 2017, they assume a level of false recall and weight to a larger Conservative lead than actually happened. A third approach is to assume there is no false recall and weight to the actual figures – one that I think currently risks overstating Labour support. Finally, there is the approach that Ipsos MORI have always taken – assuming that false recall is such an intractable problem that it cannot be solved, and not weighting by past vote at all.

Dealing with false recall is probably one reason for the present difference between pollsters. Polling companies who are accounting for false recall or using methods that get round the problem are showing bigger Tory leads than those who do not. It is, however, probably not enough to explain all the difference. Neither, should we assume that the variation between pollsters is all down to those differences that are easy to see and compare in the published tables. Much of it is probably also down to the interaction of different weighting variables, or to the very samples themselves. As Pat Sturgis, the chair of the 2015 enquiry into polling error, observed at the weekend there’s also the issue of the quality of the online panels the pollsters use – something that is almost impossible to objectively measure. While we are wondering about the impact of weights and turnout filters, the difference may just be down to some pollsters having better quality, more representative panels than others.

4,413 Responses to “Latest voting intention and the difference between the polls”

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  1. Danny

    That’s a very male dominated view of hunter/gatherers!

    It’s questionable whether the largest proportion of the food supply was provided by hunting (probably male dominated) as opposed to gathering (probably female and child dominated).

    Not just history, but pre-history too, is coloured by the prejudices of the analysts, and not infrequently, influenced by their assumptions that the dominant factor must have been provided by people like them.


    At it core Brexit solves none of the issues that we have.
    be it investment in infrastructure or healt service or improvements in basic research none of these issues have anything to do with the EU.

    To my mind brexit is seen as a US push to be the first to the moon. For some it was a vision of some bright future for others it was a stick to poke in the eye of people they oppose.

    In the case of the moon landing the eye pokers one it became boring after 3 years of the thinking it was spectacular. The idea of landing on Mars by 2000 Alpha Centuri by 2025 colonisation of Mars by 2050 were just dreams to enable the eye pokers to get enough support to get their way

    Brexit is the same. You have a thatherite vision from some and a Corbynlite vision from others and I suspect we will get none and the best we will have is a social conservative poke in the eye to social liberals.

    It is why no deal is appealing, it is a futher poke in the eye, remainers salty tears. I would point out this is what happened in the early days of Iraq 2003 which is why I keep using it as a template. Remember it was supposed to resolve all the issues of the middle east, bring democracy to everyhere solve the palestinian crisis hell we were helping the Kurds

    16 year on no one talking about that, at best we have an acknowledgement that something happened in 2003. Even on these pages people used all sorts of excuses to justify the decisions made back then. And yes back then there was more people who believed it.

    brexit is a diversion in my view at best we suffer no gain and worst we look back on thsi and say how did we get to here. What is rather sad is in all the heartfelt sympathy for the Kurds no one even thinks how the hell we got to here

    Sorry that sound like a rant….
    Well it was

  3. oldnat,
    “That’s a very male dominated view of hunter/gatherers! ”

    er, how?

    “It’s questionable whether the largest proportion of the food supply was provided by hunting (probably male dominated) as opposed to gathering (probably female and child dominated).”

    Isnt that a very sexist role allocation? Granted men are stronger, but i gather women have more stamina. Whch would be better on a long hunt where weapons are the critical element in the actual confrontationwith prey?

    If human labour is needed to cultvate earth, maybe that would be a job for the men while the women go hunting and leave the kids with the men?

  4. charles: I am not sure if it is TO or PTRP, it’s one or the other, who says that Brexit is a giant distraction.

    I think we both do in our different ways. I’ll let PTRP speak for himself. My take is that the UK is spent as a construct, with England unhappy with itself and Scotland and to a lesser extent NI and Wales all unhappy with England. We are living with pre-colonial and colonial structures which are no longer fit for purpose, but with half of England and smaller proportions of the others yearning for a restoration of the colonial era. It is political immaturity, of course, to seek to deal with the world as you wish it was rather than as it actually is.

    Brexit is but a symptom of this, and although I am a 1 on Alec’s scale, I am of the opinion that although brexit could be reversed, it might only cause more spasms of the collective psychosis, such that the route to revoking brexit requires confrontation with the reality of the problems of the UK. I think PTRP has a similar view, but expresses it more as facing the reality of the consequences of brexit

    Having said that, I would never vote for brexit in a People’s Vote and I would take a Remain result as meaning that there would be the potential to address the things that need addressing.

    Overall, my assessment now is more gloomy than in 2016, when Mrs O and I moved to Scotland because we felt that an independent Scotland would have a shared vision of its place in the world. I feel more strongly now that England will be better able to deal with itself without Scotland and that there is no benefit for Scotland to mark time while England sorts itself out.

  5. Danny

    At least speculation about pre-history makes a change from bloody Brexit!

    “Sexist”? If you mean that in a relatively equal society (which the Paleolithic might have been) the sex of the individual may have made a difference to the tasks that people undertook, probably.

    If you are using it to suggest that those early hunter-gatherers allocated roles based on a hierarchical model of the group – who knows?

    I used the term “probably X/Y dominated” because modern hunter-gatherer societies (which are the only ones we can observe) do illustrate that women of child-bearing age, who are for a significant part of their lives pregnant or lactating, don’t go off on hunting expeditions for days at a time.

    As Milton points out in her analysis of the ethnographic data collected on 20th century hunter gatherers – “Because most of the ethnographers were male, they often did not associate with women, who typically collect and process plant resources.”

    There’s no need to impose modern societal constructs on such behaviours.

    Patterns obviously vary enormously due to the availability of resources. The Inuit diet is predominantly animal, while the !Kung diet is two thirds plant foods.

    Milton’s observations on Amazonian are useful “hunter-gatherer-agriculturalists, small societies practicing shifting cultivation whose main crop was likely a single starchy carbohydrate.”

    As so often, researchers can be predisposed to assume that their “norms” must always apply. Amazonian practice suggests that conclusions that territorialism and agriculture are necessarily causally connected may all be wide of the mark.

  6. New Thread

  7. Technicolour October,
    “Brexit is but a symptom of this, ”

    There is no national will to leave the EU. Uk government is customarily decided by the support of a small minority of the population, and this drive to brexit is no exception. If the minority chooses a path which more or less works out, things tick over, but if the government simply messes up, yet more support drain away from the system. The expenses scandal as one example, where MPs were simply shown to have arranged their income to make it look smaller than it is. A massive example of self interest. Brexit is another such. Like xpense, it has blown back in their faces.

    I think you are right about the destruction of the UK. In days of empire, it was the English who ruled the british empire, but the scots, welsh and Irish were their acolytes, all superior to johnny foreigner. I still think though, that the damage occurred post WW2, when national propaganda used the myth of empire to mask the collapse of empire, and trying to recreate a functional state in new circumstances from the ruins.

    Well, the solution arrived at for a viable future for the Uk was first amongst equals wthin the EU. No one has proposed a workable alternative.

  8. danny: I think you are right about the destruction of the UK. In days of empire, it was the English who ruled the british empire, but the scots, welsh and Irish were their acolytes, all superior to johnny foreigner. I still think though, that the damage occurred post WW2, when national propaganda used the myth of empire to mask the collapse of empire, and trying to recreate a functional state in new circumstances from the ruins.

    Well, the solution arrived at for a viable future for the Uk was first amongst equals wthin the EU. No one has proposed a workable alternative.

    I agree on the timescale and without challenging the decision to be part of the EU, I would say it was deployed as a huge distraction to procrastinate over the structural changes the UK needed.

  9. Re Bowles & Choi

    When I see researchers, historians or scientists, putting terms like “Marx-inspired scenario” into their output papers, I sense that they are researching with a political aim as well as doing useful work.

    The paper [to which Colin linked] is trying to overturn what had been a fairly general view on the start of farming. Certainly the authors have dug well for facts and have clearly displayed their thinking in arguing on the productivity of farming cf hunter gathering.

    But their sources are largely Middle East, SE Asia, America, and very few for Northern Europe. A Viking coping with rising population in a fjord valley would have had much less chance of raising the area of cultivation even if the climate was warming, and would be much more likely to supplement it by migration and raiding, than in the B & C countries.

    I also noted that B & C wrote of “the rareness of the independent advent of farming – a dozen cases at most”. A bit of an arrogant statement IMHO.

  10. 4,410 posts in this thread.

    A UKPR record?

  11. @James E

    Nope. Record broken. ;)

  12. @JamesB
    “Google also assumes a relatively sedate 12mph pace for cycling.”
    Very appropriate for old fat blokes like me.
    Mind you, having been a regular cyclist for about a year I am getting faster.
    We’ve had a number of huge battles round here over segregated cycle lanes but the local council is pretty determined (and ‘brave’ as Sir Humphrey would put it). New developments are mostly car free (bar blue badge and car clubs) and I’m beginning to hear of middle class family people voluntarily giving up their cars.This despite 10+ years of trying to encourage driving by scrapping the fuel duty escalator.
    Maybe if we brexit and UK car production largely ceases it will become more mainstream for government to discourage cars, which will represent an enormous BoP deficit

  13. Anthony Wells,
    “Several polls have asked who people would blame if Brexit ended up being delayed, and as a rule they’ve tended to show that people wouldn’t blame Boris Johnson or, at least, that he would not be widely blamed by Conservative supporters or Brexiteers – the voters he needs to keep hold of.”

    Well yes, he needs to keep hold of them, but to win he needs the same thing Cummings identified that leave needed to win the referendum – the centre ground voters not strongly committed to either side on Brexit.

    The writing on the wall is that if Britain leaves the EU, then Scotland and N. Ireland will leave the UK. SNP waxed heavy on this today. The best case outcome of leaving now with a bad deal or no deal is years of further disruption and the slow collapse of the UK. All this is corrosive of a faction of support which the conservatives would once have expected to enjoy. The destruction of the United Kingdom would be a heavy burden for the conservatives to seek to carry into future elections.

    I find it comforting that you agree with many of us here, that polls at the moment are in many respects pretty useless, at least in predicting the result of an election. Anyone else reading this, who are in the habit of pointing to a big tory win based on current polling, might pay attention.

    Post Brexit the leave coalition must dissolve. Take a few years as the Brexit process continues, but if we have clearly left, then that faction of support will be gone too. The conservatives will be left in a worse situation than before they adopted Brexit as a cause to get them an election win. Far worse, because they had historically sought to attract the leave vote while also holding the remain vote.

    Which is why I keep banging on that the best outcome for con is for Brexit to be stopped…by someone else. All the events post referendum have been consistent with this guiding theme of policy.

    So, if Brexit happens it is a con disaster. If con are seen to have turned aside and caused brexit to stop, it is a conservative disaster. The only way through is if parliament, or labour, or the people stop Brexit.

    As to blaming Boris personally, this was always to be his fate. MPs voted for him in the manner of a jury giving a guilty verdict. It had to be him at this point because he led the leave campaign.

    My view is that the current situation is best parallelled by the pre-2017 election situation. That had an even stronger con lead in a more leave inclined electorate. At present the con/leave coalition is fairly well united while the remain one is sharply divided. But so long as labour offers a route to remain, it will reunite the remain vote if there is an election. So the result has to be more MPs on the remain side. (not counting con who might well be remain but are formally on the leave side).

    BJ is attempting to ensure that if another vote arises, the conservative position is as imprecise a possible. To go to an election or referendum on one clearly defined flavour of Brexit is to lose for leave. As Cummings understood in the first place.

    However…every day that passes his new leader boost unravells a little more.

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