Earlier this week some eyebrows were raised over an article by Dan Hodges which quotes a “Tory analyst” saying he re-ran Lord Ashcroft’s poll of ultra-marginal Conservative seats and claiming “We reran it in the seats we hold […] but included the name of the sitting MP. We were ahead by 2 per cent” as evidence of the Conservative party’s belief in the power of incumbency.

Now, I’ve written about political parties’ private polls and the strange mystique they seem to hold over the commentariat here before. Essentially, if you see media claims that party’s private polling shows some wonderful picture that contrasts with the public polling it’s best ignored unless they actually cough up some numbers and tables so you can see what they are up to. Your response should always be “give us the tables or they don’t exist”. Part of the British Polling Council’s disclosure rules were intended to stamp out this sort of thing: if a poll is published, the company that did it must release the figures. It does, however, only apply to companies that are members of the British Polling Council – if parties use companies like CrosbyTextor or GreenbergQuinlanRosner then even if their numbers are leaked, the companies wouldn’t be obliged to release numbers. Lord Ashcroft here writes about it being a bad sign if the Tories are resorting to comfort polling, but I think that’s rather off the mark. Back in the day the then Tory Chairman Lord Saatchi himself used to come out with dubious morale boosting figures, this is a reference from an unnamed “Tory analyst” – I suspect, like Andrew Cooper suggests here that Dan’s source was exaggerating or doesn’t know what they are talking about.

But putting the mystery “private polling” aside, what about the substantive issue, what about the incumbency effect? This is supposedly the bonus that sitting MPs get – the benefit they’ll have from people who aren’t voting for the party they represent, but because of name recognition, or because people think the MP is hard working or decent, or helped the voter with a problem they contacted them with, what is sometimes called the “personal vote”.

Let’s start with Ashcroft’s August poll. In contrast to the implications of what Dan’s source said, Ashcroft’s poll already included an attempt to get at the incumbency factor. Rather than just asking straight voting intention, it double-asked the question, first using the normal poll wording, and then asking people to think specifically about their own constituency and the candidates standing there. The intention of this – something I first came up with for a PoliticsHome poll of marginal seats back in 2008 – is to try and get at tactical considerations and personal votes. The idea is that some people may not give their *actual* voting intention in the main question, they’ll give the party they support nationally, even if at a local level they might vote tactically or might vote for the local MP they like.

This approach appears to work – or at least, some people do give different answers, especially in seats where the Liberal Democrats are players. In Con-LD seats Ashcroft found standard voting intentions of CON 33%, LAB 24%, LDEM 18%, UKIP 14%, but when he prompted to get people to think about their own constituency it became CON 32%, LAB 18%, LDEM 29%, UKIP 12%. That the difference is concentrated in Lib Dem seats does imply that it is picking up people’s tactical voting considerations, and perhaps personal vote considerations (Ashcroft wasn’t polling Lib Dem held seats, so he obviously wasn’t, but I’ve done the same in Lib Dem held seats in the past and the two-question approach makes a huge difference). In Ashcroft’s August poll in Con-Lab marginals though the two stage question did not produce any drop in Labour’s lead in the second, more “locally prompted” question. No sign of an incumbency vote there.

By definition, any incumbency bonus should be the most obvious in seats with new incumbents. In seats where the MP was already there at the previous election any personal vote should already be taken into account, in a seat with a new incumbent any personal vote should be above and beyond what the party got last time, so if there was an incumbency effect we would expect to see a party doing better than average in seats with new incumbents like the ones Ashcroft polled. Again, this was not the case – in Ashcroft’s August poll the swing to Labour was about 2 points higher in the marginals than the GB polls at the time were showing.

That bit of evidence seems clear then. The problem is, the incumbency effect is not a vague theory, the evidence for it happening at past elections is pretty damn solid. In 2010 Labour lost an additional 2.2 percentage points in seats where an incumbent MP stood down compared to seats where the incumbent contested the seat. The Conservatives vote rose by 2.9 percentage points in seats where an incumbent stood down and they lost the incumbency effect. In seats with an existing incumbent it rose by 3.8%, in seats with a new incumbent first elected in 2005 the Conservatives increased their vote by 5.6%. The same happened in 2005, the Conservatives did 1% worse where an MP retired, 2.5% better where there was a new incumbent.

Going further back the record is more patchy (while the Conservatives did worse where MPs stood down in 1997 and 2001, they didn’t do better in seats with new incumbents), but there is a strong and consistent effect in elections following on from an election where a party gained many seats. It is even clearer in the seats that a party gained at the previous election (the so-called double incumbency bonus), so in 2010 Conservative MPs who gained seats from opposing parties in 2005 did 1.9% better than average, in 2001 Labour MPs who gained their seats in the 1997 landslide did 2% better, in 1997 Labour MPs who gained a seat in 1993 got a bonus of 4.3%, in 1992 Labour candidates who gained seats in 1987 got a bonus of 2.7%, in 1987 Conservatives who gained seats in 1983 enjoyed an extra boost of 3.9%. For Liberal Democrats, incidentally, the figures are even bigger. (*)

There is no reason to think the same will not happen next time. New incumbent MPs will do better than average, seats where an MP retires will see the party of the retiring MP do worse. It will affect all parties, but because most of the battleground seats between Labour and the Conservatives are ones with new incumbent Conservative MPs who gained the seat in 2010, on this occassion it will favour the Conservatives.

If that is the case though, why didn’t the Ashcroft polling pick it up?

Well, there are a couple of potential reasons. One is obviously that the incumbent effect has vanished for some reason. Personally I think this unlikely – the general trend has been for MPs to devote ever more of their time to constituency matters and their “social worker” type role – but it is certainly possible. Alternatively it could be that it’s there, but that the polls don’t pick it up. Perhaps such things don’t really emerge until the election campaign itself, or perhaps the big differences the “two-stage question” approach produces in Lib Dem seats are just tactical considerations and there isn’t really a good way we can get at incumbency effects. Alternatively, you need to remember that the August Ashcroft poll is just one poll – the previous Ashcroft poll of marginal seats in January 2013 (the bigger one that did lots of different groups of marginal seats) did actually show a very small pro-Conservative incumbent effect from the two-stage question in Con-Lab seats, and did show the Conservatives doing slightly better in the marginals they were defending than in the country as a whole, the patten we would expect to find given the past history of incumbency effects.

And that brings us back to the original question and the orginal polling that whoever was talking to Dan thought they had seen. If there is an incumbency effect, then on past experience it will be a couple of percentage points. If asking a question a different way changes a 14 point deficit into a 2 point lead, then that’s not an incumbency effect, that’s a shonky question.(**)

I expect there to be an incumbency effect, but it’s going to make a couple of points of difference, not 16 points. It’s one of the reasons I think the Conservatives could probably get a majority with a 7 or 8 point lead rather than 11 point lead they need on paper, why the Labour party need a slightly bigger lead than what a uniform swing suggests. It’ll be a small effect at the margins though, not something that transforms the election. It makes the election a bit harder for Labour to win than uniform swing suggests, but not much. It makes seats a little easier for the Conservatives to defend, but they still have a mountain to climb.

(*) The 2010 figures are from Curtice, Ford and Fisher in Cowley & Kavanagh’s British General Election 2010, the figures for 1983 to 2005 are from a research note by Tim Hallam Smith here, alas behind an expensive academic paywall.

(**) At least, it is with a Tory 14 point deficit. As we’ve seen from the two-stage questions above, in Lib Dem seats it’s a bit of a different story, but that will be tactical considerations as well as incumbency

150 Responses to “On Private polling and incumbency effects”

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  1. My private polling suggests a labour landslide in 2015.

  2. Publish the tables or it doesn’t exist ;)

  3. Labour minority I think.

  4. @AW

    Second para – ‘mystique’

    Hope that helps, H

  5. @AW
    “This approach appears to work – or at least, some people do give different answers, especially in Liberal Democrat held seats.”

    I think they were Con held, actually??

    See our discussion on last thread?

  6. “Essentially, if you see media claims that party’s private polling shows some wonderful picture that contrasts with the public polling it’s best ignored unless they actually cough up some numbers and tables so you can see what they are up to. Your response should always be “give us the tables or they don’t exist”.

    2011 Scottish election….

    “Salmond’s cautious assessment is confirmed by senior party figures, who admit privately that its private polling puts the SNP three to four points behind Labour”

    Now we all know the outcome of the Scottish election just 6 weeks later so I think it’s best parties keep private polling to themselves or it really could give the opposition the upper hand and extra motivation if they see their opponents private polling’s suggests they are behind.

  7. nickp

    My private polling suggests a labour landslide in 2015.

    Anthony Wells

    Publish the tables or it doesn’t exist ;)

    Ha Ha Ha

  8. Howard – yes, Ashcroft’s were (so obviously weren’t picking up incumbency in those seats), but I’ve used the same technique in Lib Dem held seats on several occassions and it does make a huge difference there.

  9. @NickP,

    I suspect once your poll has been properly weighted and the number of old lefties has been weighted down, it will probably show a hung parliament….

  10. A follow up question to the follow up question “in your Constituency” should be “well why didn’t you say that in the first place?”.

    @ Nickp

    Don’t give him the tables. He will just pick holes in it like pointing out that the 5 people you sampled were Labour councillors like that makes any difference.

  11. Neil A
    I am surprised you doubt the data that NickP has presented. We all remember his astonishing accuracy in the last London Mayoral election.

  12. I think we can safely assume NICKP’S private polling would had included the following.. a Methodist minister, chairman of a bank, labour councillor, political advisor and a chairman of a charity. Of course all of whom are now EX…

  13. Private polling is private. That’s why it’s called private.

    But it was decisive, I’m telling you.

  14. By definition, any incumbency bonus should be the most obvious in seats with new incumbents. In seats where the MP was already there at the previous election any personal vote should already be taken into account, in a seat with a new incumbent any personal vote should be above and beyond what the party got last time

    Well that’s the theory, but in practice it may be less clear-cut. The previous MP may have been useless or even alienating, they may have been caught up in scandal (particularly over expenses) or they may be Lembit Opik[1]. So there may be no previous incumbency bonus to unwind.

    More significantly if there is one it may not all unwind at once. This will be especially true if the ex-MP is continuing to fight the seat but loyalty to the old regime may transfer to the new candidate because the work done to acquire it will also involve caseworkers, councillors etc who will still be around and gratitude will still be felt. Six of Ashcroft’s eight Lib Dem seats were Lib Dem to 2010 and this may explain some of the swing there, not just tactical voting.

    The other component, that earned by the new MP, may also be less than thought. In part this will be because earning such goodwill is a cumulative process, but I also wonder if there is a particular problem with this particular batch of new MPs. Cameron’s A-listers will tend to be more ambitious and London-centric and with shallower roots in their constituencies. There may also be a rather dismissive attitude towards constituency work, which they may delegate more. So they may not be building up IB in the same way – and may not see it as significant enough electorally. Such attitudes are probably on the rise in all Parties and reflect the increasing professionalisation of politics and the reasons why people want to be become MPs, but they may be a particular problem with many of this intake.

    The high IB for 2005-elected Conservatives may also give a clue to another factor in IB. Those MPs had spent the previous five years opposing the government and it is much easier to get involved in local campaigns from that position than as same a government backbencher eager for promotion. Part of an IB may be not just direct contact with constituents but also being seen as being concerned with the constituency.

    [1] Montgomeryshire was one of Lord A’s eight (and showed a rather high PC VI fwiw). In British public opinion the line between beloved eccentric and irritating famewhore is a thin one.

  15. My private polls tell me my thoughts will go straight into moderation. They never let me down. I can address the problem they are picking up by saying no more here ever, or by keeping on saying things.

    The incumbency bonus is interesting when the margin between parties means the outcome of an election is likely to be influenced by it. With Labour solid on 38 (can we really talk of them being a few points higher when nonsense like the Flowers affair appears to have some kind of an effect on those extra few points?) and the Tories (let’s just say) well behind, is the bonus likely to swing anything at all, election-wise?

    Still, let’s see if my private polls are corret?

  16. Yeah, well, they are certainly ‘correct’, all right. (Not sure about ‘corret’, although I aim to ensure they are 22-corret if at all possible.)

  17. Anthony
    Thank you. I hope it was helpful rather than nitpicking and I see you have dealt with it.

    I am sure your polling has nothing about it with which you would be disappointed. Keep them coming, do.

    Roger Mexico

    All good points. I know from experience that to put up a show against an incumbent, at least in a marginal, the challenger must

    a) start early, one cannot be too early. Some fuddy duddy constituency committees wait about for two years before even thinking about the next PPC. This is most unfair to whoever is eventually chosen.
    b) the challenger (if new and not the same person as last time) has to distance himself from the previous one (passively is OK).
    c) must establish a good local knowledge and have a photo op every week in the local press and must, must, have an up and running web site, indeed several related ones.
    d) build the activist base immediately through any method possible and get them working.

    I could go on but it should be clear that winning a seat is a 5 year exercise and needs 60 hours per week continuous effort, building to 80 pw in the final 3 months.

    Every elector, not just every household, should be personally contacted. Work it out what that entails.

    How many do that I wonder? They will probably win if they do.

  18. Brilliant article Anthony, thank you. Proper serious analysis.

    Is the most obvious explanation that Dan Hodges has just made it up? He seems increasingly desparate to find ‘evidence’ to damage the party he claimed to support

  19. Howard ,I doff my cap to you on the basis of your last post. You are the activist’s activist !

    Just been looking at the by-election results , and what a curious , incoherent , story they tell. All that effort by footsoldiers of all shades… fighting for a tiny packet of power and influence , and then a c**t like Flowers comes along and Jo(e) Public thinks that ALL local councillors are Drug crazed Wastrels.

    (c**t = *lo*, by the way).

  20. howard

    I am sure your polling has nothing about it with which you would be disappointed. Keep them coming, do.”

    Maybe not – sometimes when I embellish the truth I wish I’d gone a bit further and its a bugger when its too late.

  21. Ed Miliband’s on Desert Island Discs on Sunday. Will it affect his ratings?

  22. Ed Miliband’s on Desert Island Discs on Sunday. Will it affect his ratings?

    Such blatant left-wing bias from the BBC ;-)

  23. Farnham Grecian,
    What a delightful name.Quite a few of us agree with your opinion of DH.He is a
    Bit odd.Rather like a spurned lover,he hates what he loved before.Sad really.

  24. A in W
    The amazing thing is (to me), I only know about this Dan Hodges chap through UKPR. He’s a bit like Kim Kardashian, of whom I know nothing, except that she is known, also by me now.

  25. @Howard

    As another poster reminded us, Ashcoft wondered at one point whether there had been an unwinding of *his* campaigning in the marginals.

    As a resident in two Lab/Con, Con/Lab marginals over the last decade, I’ve had maybe a couple of Tory leaflets delivered by hand in that time, the rest comes direct from CCHQ.
    I suppose I tend to live in active Labour wards, but plenty in my street voted Tory in 2010.

    Even though LDs are never really in contention, there is a monthly newsletter come rain or shine, and weekly leaflets for months ahead of any election.

  26. Thanks for the detailed article Anthony.

    Something to add to the debate. I found this recent poll asking people what they thought of their MP:


    “The response also differs depending on which party the MP belongs to. The net score among respondents with Labour MPs was -5, and among those with Conservative MPs -13, slightly worse than the national average. Liberal Democrat MPs, however, scored +14. The ability of that party’s MPs to dig in to their constituencies appears to have survived the various traumas of coalition politics.”

    This is obviously a national poll, so not relevant to this marginal poll, other than I guess more LD’s are in marginals. but maybe Ashcroft should ask these sorts of questions in his next poll to help settle the question.

    And it is an important question to settle as Ashcroft concludes his article:
    “There is nothing wrong with trying to cheer up the troops. But the correct response to bad poll numbers is to learn from them and change them, not to try and rebut them. Boosting morale is one thing; being in denial is another thing altogether.”

    By Hodges sowing FUD with some sort of plausibility, it prevents the party learning from the real numbers and taking steps to try and change those poll numbers. Is Hodges a Labour secret agent :)

    When they really DO need to look at those poll numbers and start asking people where they are going wrong – for the good of the country so we don’t have two more years of doing things most of the public doesn’t want.

  27. I’m a bit sceptical of two-question polls.

    I think there is a tendency in some respondents to give a different anser to question 2 – regardless of the actual terms of the question.

  28. This is also worth repeating from that mp poll linked above:

    “Of those who had contacted their MP and were ‘Very Satisfied’ with the response, 86 per cent said that they were satisfied with the MP, and just 3 per cent were not, a net score of +83. At the other end of the scale, of those who had contacted their MP and were ‘Very Dissatisfied’ with the response, 93 per cent said that they were dissatisfied with their MP, a score of -93.

    In other words, the views of those who’ve contacted their local MP about that MP are almost entirely dependent on how satisfactory the contact was. This relationship holds true regardless of the party leanings of the constituent.”

    So some questions about “have you contacted your mp” and “were you satisfied with the response” broken down by party in marginal seats would be VERY revealing.

    Lets hope Lord Ashcroft reads UK Polling report comments :)

  29. Has anyone read lib dem Nick Harvey’s prediction today?He says EM has already won the next GE,and labour will have a 15 seat majority.

  30. How often do questions specifically ask if people will vote tactically?

  31. Typically honest intervention from David Davis re Co-op and what should have been apparent in past 2/3 years.

    He could still make an excellent Tory leader – I think the party and the country would know exactly where he stood on each issue.

  32. Well, something that might affect local VI has boiled over this week – BIS have had problems with their budgets (he said, choosing his words with care to avoid moderation), and as a consequence the higher education budget is going to get absolutely slashed to the bone in the next 2 years.

    There was an attempt to keep this all under wraps, but with a Lib Dem presiding at BIS, and a Tory presiding over HE, there is blaming going on.

    The already-slim hopes of Lib Dems in academic-heavy seats may well have gone south as a consequence. They’re talking about hundreds of job losses from one of our most successful and internationally-respected sectors. A very sad business.

  33. Anthony,
    Won’t the incumbency effect be already included in the VI but effectively spread over every seat?
    If that’s correct, then the Lab lead in seats where there is no incumbency is really higher than VI suggests and lower in seats where it does, as opposed to being ‘above and beyond’.

  34. Labour made substantial gains at the 1966 election.Having looked at the figures it’s not very obvious that the new MPs enjoyed below average swings against them in the 1970 election.

  35. For those ike me staying up to endure the agonies of the cricket, and even for those who can’t bear the cricket, here’s Boycs’ pithy observation after the last day’s carnage…

    Geoffrey Boycott, Ex-England batsman on BBC Test Match Special
    “England have an 82-page booklet on what to eat but one guy comes in and bowls at 90mph and they can’t handle it.”

    100% of voters (who care) might currently agree with this assessment…

  36. HOWARD
    I liked your analysis of the opposition, new candidate position. Would you not add Anthony’s “social worker” function, true of the opposing candidates, especially if they are close to unions, health, housing or education services, and are able to pick up the phone or reply to unfairly treated constituents
    Donj’t worry, am working on the day job,. Five in the morning here in Vientiane, and a violet cast to the early morning sky. Be good dogs for your Daddy.

  37. “Ed Miliband’s on Desert Island Discs on Sunday. Will it affect his ratings?”

    If he avoids any middle-of-the-road stuff, and selects several Simply Red tracks, and perhaps a little bit a Billy Bragg, my gut feeling is that it would firm up the Labour VI.

    Anyone else care to comment?

  38. He could play “Money’s too Tight to Mention”, or “No Direction”…

  39. Sort of on topic. About polling!
    Danish local elections were held this Tuesday. The national broadcaster (DR) did a completely botched exit-poll, which ended up being 7 points off (22.5% for Soc.Dem. in the poll, 29.5% in the end). The party leaders bought into it, the Soc.Dem. prime minister even apologised for the terrible result. Now it turns out that the exit poll was based on just 150 interviews and then added in voting intentions from previous polls. Embarrassing! A debate has now begun whether to ban exit polls outright. Currently they are allowed even while voting is still ongoing.

  40. The article quoting a “Tory analyst” was by Dan Hodges. Enough said. I long ago stopped reading anything written by Hodges.

  41. Helle Thorning-Schmidt should ask her father in law about botched exit polls. Unfortunately his went the other way.

  42. Chris Riley

    […]BIS have had problems with their budgets …and as a consequence the higher education budget is going to get absolutely slashed to the bone in the next 2 years.

    Does it have anything to do with this:


    which I already linked to a while back. I’m surprised there hasn’t been more fuss about it – especially as it would give the Daily Mail an excuse to blame Romanians for everything.

  43. Wittiest comment Award on the Co-op kerfuffle thus far has to go to George Monbiot on Any Questions tonight. Talking about the Reverend Flowers, he said that he couldn’t possibly be a proper banker because he bought his own cocaine and, whilst hopeless at his job, didn’t actually bring about the financial ruination of the country..

    He also made some quite interesting comments about the current Tory peer Viscount Ridley, once Matt Ridley the former hapless Chairman of Northern Rock. Whoever said failure didn’t bring its own rewards?

  44. Anthony,

    Given that 2010 used new boundaries (as did 1997 and 1983 when many more seats changed hands), has there been any research as to whether part of the incumbency bonus is actually down to people adjusting to the reality of the political dynamics in the new seat, rather than to the person of the new MP ?

    I remember an anecdote from the 1979 election when members of the election night panel debated the value of incumbency – thought to be around 500 votes in a typical seat. Two panellists agreed, a third said no. He held his seat, the other two did not.

    Historically, it seems to work for Liberals / LDs more than for other parties, though there are isolated exceptions. However, those exceptions have typically been seen as mavericks within their own party.

    Could it be that the public simply prefer an MP who is not perceived as a career politician or lobby fodder ?

    If so, the tendency for professional career politicians with little outside experience or independence of opinion may well lead to reduced incumbency effect.

  45. (reposted from previous thread ‘cos I hadn’t realized everyone had already migrated to a new one hours before and, well, I put some effort in on it…)

    Ok, I’ve now read the Collins article… happily, regarding paying for Murdoch, my friendly newsagent lets me have papers half price… except at weekends. (I got a free cuppa too, which basically left me in credit. Thanks Rupe…)

    Since Col is not in the habit of giving quick article summaries, for those unwilling to do the homework he sets, here’s a quick précis:

    The central thesis, is that Miliband interprets 2008 as the year “that an experiment in neoliberal economics… came to a decisive full stop”.

    Whereas Collins thinks it’s the year “the money ran out”.

    He then goes on to argue, that the lack of money has implications for the Public Sector, which still needs reform, but Miliband has in Collins’ view not much of a position on what to do about health, education etc., either in terms of how to improve it, or in terms of dealing with the impact of lack of money on the Public Sector.

    To the extent that Ed. M does have a position on public sector and reform, Collins maintains, it tends to be at odds with the Blairite prescription. And he reels off examples of that prescription that most are automatically au fait with: “There is not a multitude of ways to make large service organisations responsive to their citizens. Targets can be set, people can be given purchasing power, professional expertise can be given a licence to act, those who offer a service can compete for custom, inspectors can come round with clipboards unannounced.”

    He feels Miliband is neglecting these policy areas since Miliband thinks the electorate are more concerned about cost of living, and sorting out capitalism. And that this will be a problem for Miliband as not everyone is suffering the cost of living thing, and fewer will be still if “a stuttering economy does begin to deliver any reward to household budgets… he will find people are just as concerned about schools, hospitals and crime as they ever were.”

  46. “shonky – A compound word from the two terms ‘shocking’ and ‘wonky’ meaning that something is so bad or precarious that it is actually shocking. Can also be changed into the adverb shonkily”

    You learn something new every day.

  47. I can furnish the readers with NickP’s tables:


    (bet I’m right! :))

  48. The incumbency effect is pretty obvious, unless you are a really cr-p mp. You have resources to run a const office and do casework. I am assisting a candidate challenging for a seat: we are being completely outspent: volunteers running on a shoestring. (our MP is also a millionaire…)

  49. @Howard

    “Every elector, not just every household, should be personally contacted. Work it out what that entails.”

    I’ve not been as long on this earth as some posters here, but over five General Elections and other assorted EU, Scottish and local ones, I have never, ever had a politician at my door for canvassing reasons.

    I invited a councillor out to investigate a problem, and all he did was blame the other lot (a different party in Government) for not giving them enough money to sort the problem.

    In fairness to all politicians out there, I doubt I would be very receptive (to any party).

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