On Sunday there was a mruk Cello poll on the London elections and we needed to be a bit wary as we had neither track record nor methodological details to judge it by. Well, their full tables are now up on their website here so we can have a proper grub around in their methodology.

The poll was a phone poll. It was weighted by normal demographics, ethnic group (as all the London polls in the campaign have been apart from YouGov’s early ones) and recalled 2005 vote. The past vote weights are in practice almost identical to ICM’s in terms of party support (actually they should in theory be marginally kinder to the Tories, but the difference is a tiny fraction of a fraction of a percentage point, so can be disregarded).

That’s not to say the samples are identical, there is actually a vast difference in terms of the proportion of non-voters in the sample. Comparing the samples between mruk and ICM, mruk’s is weighted to contain far, far more people who claim they voted in 2005. In ICM’s weighted sample 44% said they did not vote and 4% refused to say or didn’t know. In mruk’s sample 21% said they didn’t vote and 7% refused or wouldn’t say, so only half as many 2005 non-voters as ICM.

This probably isn’t all down to weighting, but down to how the question is asked. In the two companies raw, unweighted data 33% told ICM they didn’t vote or weren’t registered but only 20% said they same to mruk – my guess is that ICM used wording that prompted people to make it more socially acceptable to admit that you didn’t bother to vote in 2005. Either way, the impact on final voting intention figures probably isn’t huge, people who didn’t vote in the general election are probably least likely to vote in the mayoral election.

Having weighted the data, mruk applied a turnout filter that took all respondents who said they were 8/10 likely to vote. This is slightly more demanding than ICM’s normaly filter, but laxer than Ipsos MORI’s. This equated to 73% of the sample in this case.

I suspect it is identifying which people are likely to actually go out an vote that is the main challenge in elections like this with a lower turnout. Just asking people to rate their chances from 1 to 10 has limitations since even the proportion of people who say they are 10/10 absolutely certain to vote is often higher than the proportion of people who actually vote. In ICM’s case they pre-empt their question with wording intended to coax people into admitting that they might not vote: “Many people we have spoken to have said they will NOT vote while others have said they WILL vote. Can you tell me how certain it is that you will vote?” and found a much lower proportion of people claiming they were 10/10 certain to vote. (Likelihood to vote doesn’t seem to work the same way in YouGov polls – in polls on low turnout elections their figures without any filtering by turnout have in past been far more accurate than ones with)

The bottom line for those wondering whether this is a reputable poll that we should pay attention to is yes, there’s nothing wrong with the methodology. That said, if the polls continue to produce contrasting figures then (unless the result in bang in the middle and everyone can claim they were within the margin of error) someone is going to have been wrong come May 2nd.

I’m told that there will be another mruk poll in the Sunday Times this week.


11 Responses to “More on that mruk poll”

  1. I must say the data is well presented in a very readable form . As to accuracy time will tell but I think that mruk will be an assett to the polling industry , hopefully they will become members of the BPC .
    There was also not mentioned by Anthony a GE voting intention question Con 41 Lab 35 LD 18 these figures don’t look outlandish at all .

  2. Mark,”others” only 6%?

  3. True Vino perhaps a little on the low side , the same figure 6% said they voted for Others at the 2005 GE whereas the actual figure IIRC was just over 7% in London .

  4. Thanks Mark – I assumed the figures were nation wide but they of course only apply to London hence my surprise at 6%!!!.You are right at just over 7% – 7.3% to be exact,I suppose inflated by George Galloway’s success.

  5. Vino , I suspect there is also some shy BNP voting intention in the answers .

  6. As Scotland, Wales and Northern Ireland all have significant “Others” in there own countries they push up the UK “Others” total.

    With the SNP current polling as high as a third of Scotland’s 8% of the Uk electorate, we boost the Uk others by close to 3%. As the SNP, PC and the Unionists and Republicans don’t stand in London ( that I know of) you’d expect others to be lower than in the rest of the UK.

    Oh just in passing at the SNP conference on Sunday alex salmond set us the target of gettting 20 seats at Westminster with the hope of holding the balance of power after the election.

    That’s fourteen more than now and ten more than my prediction, so even though it’s after midnight I better get out and start canvassing.

    Peter.

    Peter.

  7. God Bless You PETER – an extra 14 Westminster seats / that’s gonna be very difficult because 11 of the seats are already in the “blue” corner !!

  8. Mike,

    This whole 11 seat nonsense isn’t evidence based. Since you’ve been making it Tory support in Scotland has only once reached 19% and it’s been as low as 144 averaging about 17%.

    If the surge is coming then there is no sign of it yet, and until there is all your posts are just wishful thinking.

    If you really are serious about 11 seats why not list them with the share of the Scottish vote the Tories would need to get to win them.

    Peter.

  9. From Anthony’s list of Tory target seats.

    Based on the fact that since 2005 the Tories have been mainly static in Scotland, with the SNP up Labour and the LibDems down.

    1) Perth & Kinross (SNP), (30th Tory target) swing 1.65%.
    Pete Wishart is the MP and the SNP vote has doubled in the polls since the last election in 2005. SNP hold

    2) Angus (SNP), (39th Tory target) swing 2.1%.
    Mike Weir is the MP and again SNP well ahead from last election.SNP hold.

    3) Dumfries & Galloway (Lab), (51st Tory target) swing 2.85%.
    Russell Brown is the MP and with ex MP Peter Duncan the Tory candidate, with Labour behind the 2005 poll rating a possible Tory win.

    4) Edinburgh South (Lab), (76th Tory target) swing 4.55%.
    Nigel Griffith MP but it is the LibDem 4th target seat in the UK, could be a LibDem win if SNP takes votes from Lab , possible Con second but no better.

    5) Ochil & S Perthshire (Lab)(87th Tory target) swing 4.95%.
    Gordon Banks is the MP, but the SNP have Annabel Ewing as candidate and it is a high SNP target with only a 1.5% swing needed. Possible SNP gain.

    6) Stirling (Lab) (100th Tory target) swing 5.45%
    Anne McGuire MP, Tory’s were second, but it is a LibDem target seat too. Labour hold.

    7) Berwick, Rox & Selkirk (LibDem) ( 121st Tory target) swing 6.5%
    Micheal Moore MP, even with Libdems down this will be a LibDem hold as majority is 5,000.

    8) Argyll & Bute (LibDem) (122nd Tory target) swing 6.5%.
    Another LibDem hold, LibDems may be down, but Labour and SNP votes are low and unlikely to go to Tories, A big swing to the SNP might let the Tory’s steal it.

    9) Renfrewshire East (Lab)(133rd Tory target) swing 7%.
    Almost certain Lab hold, not enough SNP or Libdem votes to change this two party seat.

    10) Moray (SNP) (139th Tory target) swing 7.3%.
    Angus Robertson MP, over 5,000 majority SNP hold.

    11) Edinburgh North (Lab) ( 139th Tory target) 7.75% swing.
    Mark Lazarowicz MP, Libdem target 16, Tories currently third, probable labour hold, but outside chance of LibDem gain.

    So Mike that is one chance in the Tory current top 11 in Scotland.

    Peter.

  10. Pete Wishart’s seat is Perth & North Perthshire, not Perth & Kinross.

    And the Tories will be lucky if they end up with three seats in Scotland–eleven is never going to happen.

  11. Peter,

    You may be closer to the Borders than I am in Hertfordshire, but I think that you may be wrong about Dumfries & Galloway. There’s a large overlap with Alex Ferguson’s seat and Peter Duncan is standing again, so I would say that on current trends that is a likely Tory gain unless you think the (reduced) SNP support in the rural parts of the seat will vote tactically for Labour as they would appear to have done in 2005.

    I also think that Berwick Rxburgh & Selkirk is another likely gain – almost equivalent seat taken cleanly at Holyrood last year.

    I agree that other gains will be harder to make.

    Notice you did not mention Edinburgh SW – opportunity for an upset ?