A constituency poll by any other name?

ICM has just released a constituency poll of Sheffield Hallam. Before a spiral-of-silence adjustment, Nick Clegg is on 40%, and his Labour challenger Oliver Coppard is on 36%. These figures are based on responses from 336 individuals, and so have a margin of error of 5.3%.

This compares with a recent Lord Ashcroft poll, which showed Clegg on 36%, and Coppard on 38%, but without naming the candidates. These figures were based on responses from 733 individuals.

Given these numbers and their associated margin of error, it’s not clear to me that we can conclude much about the relative merits of naming candidates versus not naming candidates. Suppose Clegg wins by 38% to Coppard’s 37% — we would be none the wiser.

Of course, there are other reasons for thinking that constituency polls which name candidates should be more accurate than constituency polls which do not name candidates.

The argument for naming is simple: voters in ballot booths are given a list of names; polls estimate what happens in the ballot booth; therefore polls should use the same prompts found in the ballot booth.

The argument against naming is more complicated, and may trade (entirely on in part) on the survey mode.

Suppose you receive a phone call from a pollster. Being a frequent consumer of polls, you oblige. You are given a list of names, but the list is quite long. You can’t quite remember the name of the Labour candidate, but you’ve heard of that Nick Clegg. Unwilling to look foolish in the eyes of the interviewer, you say, “Clegg, he’s the one”.

In other words, naming candidates in phone surveys biases responses to the most well-known candidate.

This name recognition effect probably doesn’t make sense to people with strong party identification. But there are fewer and fewer such people around, and there’s a long history of public opinion research which suggests that public opinion doesn’t really exist outside of a particular measurement context.

Ideally, all parties which conducted named-candidate polls (I’m looking at you LibDems!) will release these polls after the election so that they can be compared to the nearest (in time) Ashcroft poll. Only then will we be able to get some idea of the relative accuracy of named versus unnamed candidate polls across a range of constituencies.

Comments welcome below!

5 thoughts on “A constituency poll by any other name?

  1. Good blog, Chris.

    I strongly suspect we will not see the lib Dem polls after the election. What we really needed was for the good Lord to poll both ways and publish both throughout the campaign. It’s what I would have done with unlimited funds and a methodological interest. May have helped him going forward if he intends to continue in the same vein. Methodology around constituency polls patchy at best with a so so record (hence the it’s a snapshot not a prediction lark) but, if you are going to stake your polling reputation on them, would be better to do rigorous testing on them around the time of an election.

    Suspect this argument will continue for some time.

  2. Surely in the case of Hallam how much difference would naming Clegg make, how many voters there are unaware that Clegg is their MP when they are asked to think of their constituency?

  3. However accurate the Ashcroft polls prove to be, I think Hallam has to be considered a special case (along with
    Thanet South and some Scottish seats). In Hallam, Tories are voting Clegg because he’s an important element of the Tories staying in power. Is that an ‘incumbency’ vote based on bueger MP’s local reputation? No, it’s a personal vote yes, but one that would appear to be based on national strategic factors rather than his being a “good constituency MP” (the line that local Lib Dems usually rely on).

    In Thanet, Farage is high profile and very divisive compared to other Ukip candidates elsewhere. Votes that are cast tactically against him are undoubtedly related to who he is, but that’s quite rare – usually personal votes for or against relate to an incumbent MP, or occasionally a returning previous incumbent, rather than someone who has never been an MP before.

    Scotland is an interesting set of cases because there are effectively two kinds of seats (excluding those that the SNP are dead certs to win, namely their current seats and those Labour has simply abandoned). The first kind is where the incumbent is relying on other unionist voters to lend them their votes to keep the nationalists out – Jim Murphy, and perhaps other MPs in seats that recorded high losing Tory votes in 2010. The second kind is where the incumbent is relying on their own reputation as an MP to get them through, often in seats where there are barely any Tories to defect. Douglas Alexander definitely falls into this category, as do MPs such as Willie Bain and Margaret Curran. Some seats have elements of both – the Scottish Lib Dem seats in particular, with high squeezable Tory votes and big name incumbents.

    At a guess, the Ashcroft unnamed polls may pick up the former trend – tactical voting – but would pick up the latter trend – ‘personal votes’

  4. Pingback: UK Polling Report
  5. Time to pack up this nonsense and get proper jobs after you got the result soooo wrong

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