The full results of the YouGov poll are still up on their website here. As usual they asked a wide variety of subjects, so here’s a run down of some of the other findings.

Gordon Brown’s figures continue to plummet, his net “good job” in the YouGov poll for the Sunday Times was down to -20, as compared to -10 in November. Cameron’s figures are up at plus 25. There were figures for Nick Clegg, but so far these mean very little indeed, with well over half of respondents saying don’t know.

Less good for Cameron was one of those focus group style questions asking what animal people thought politicians resembled: Brown was seen as a bear, a nice strong image there. Cameron was seen as a snake, oh dear.

In reality these questions aren’t really suited to a quantative survey, it depends too much on what options you give them, I remember arguing about the wording for we did about whether tortoise should be included in the list, since it was so obvious it was just leading people to give that negative response about Ming Campbell. In this case there was one very obvious “positive” animal for Brown, so Labour supporters all said bear – negative repsonses from Conservative supporters were split between things like Ostrich, Hippo and snake. For Cameron it was the opposite, negative responses were concentrated on snake, but positive responses from Tory supporters were split between leopard and bear (neither of which are particularly Cameronish). If the question tells us anything, it is that for those who still have a positive view of Brown, his qualities are very well defined. In Cameron’s case his negatives are well defined, but his positives aren’t. (My favourite outcome in one of these comparison questions was an ICM focus group that found Cameron was seen as a some upmarket BMW saloon car, the type slightly flashy salesmen would drive. Ming Campbell was a nice old Jaguar. Brown was a tank.)

Moving on, the Sunday Times poll also covered nuclear power. Asked if they approved of a new generation of nuclear power stations to replace current ones, a majority (59%) approved, with 27% opposed. Conservative supporters were most supportive, but even a plurality of supporters of the Lib Dems – the only one of the three main parties to oppose the plans – were in favour, 48% to 39%. Overall 39% of respondents thought the proportion of Britain’s energy needs filled by nuclear power should increase in the future, 17% though it should stay the same, 25% though it should be reduced or entirely phased out.

It’s worth pointing out again the unusual contrasts between men and women on the issue of nuclear power. On most issues men and women think much the same, nuclear power is an exception. Men overwhelmingly favoured the decision to build a new generation of nuclear plants by 74% to 20%, women were far more cautious, with the balance in favour 44% to 32% against.

The Sunday Times also did a series of questions on “rip off Britain”, which had a nuggest of good news for the big supermarkets, who were very much the whipping boy last year. Overwhelming majorities of respondents thought that the public were ripped off by petrol companies, rail companies, dentists, banks and local councils…supermarkets alone broke the trend, with 61% of people thinking the public got a good deal from them.

Finally there were a couple of “are you are heartless unfeeling bastard?” questions. 57% of people claimed they paid great attention to the way food they bought had been produced. 60% said they would pay £1 extra for chickens reared in more humane conditions.

Questions like this where there is an option that is obviously the more socially desirable invariably give worthless results, it’s so much easier to say it in a survey than actually fork out the money. Have sales of non-free range chicken collapsed as over 60% of consumers spurn them for more humane alternatives? Of course not, the supermarkets report sales of chicken slightly up, with Tesco saying the proportion of customers buying their Willow Farm bird which have a higher standard of welfare are “slightly up”.

My favourite example of this type of question was done by Populus after the Boxing Day tsunami, they asked respondents how much money people in their household had donated to the relief effort…and came up with a figure considerably larger than the actual donations made by the entire country. People will very rarely tell pollsters they are heartless bastards.

I don’t regularly report US polls here – there are too many of them and large numbers of dedicated US sites that do it much better than I could, but the New Hampshire primary polls are worth a look: what went wrong?

Since the Iowa caucases all the polls had shown Obama leading Clinton, mostly with large, sometimes double digit leads, yet Clinton ended up winning. It’s only one primary, rather than the election itself, but in the scale of the error it’s comparable to the 1992 polls in the this country.

There are already lots of post-mortem posts going up on US sites with lots of possible explanations. From the professionals there are comments from Nancy Mathiowetz of the AAPOR, John Zogby, Scott Rasmussen, Gary Langer, the head of polling at ABC news and Frank Newport of Gallup, while the best blog analysis comes from Mark Blumenthal on Pollster.com.

Everything seems to be at an early stage at the moment, not least because there is very little data available. US pollsters aren’t compelled to release data tables in the way UK pollsters do, and many offer subscription services and charge people for more detailed information. There are also a lot more pollsters in America, and while those who are members of the AAPOR are supposed to give full details of methodology, not everyone is. I hoped yesterday to go through the tables and compare the make up of the samples with the people who actually voted according to the exit polls, but in most cases the data isn’t there to do so. At the moment therefore these are just early thoughts, no doubt pollsters will release data and have an investigation later.

What can we tell. Firstly, the polls on the Republican primary were pretty good. If you look at Charles Franklin’s graph here on www.pollster.com (second one down), the dots are pretty much on target in the Republican graph (you expect them to all be a bit down and to the left when comparing US polls with actual results because they don’t repercentage to exclude undecided as they do in this country). Given that most polls for the Democrat and Republican race were actually done together (people voting in one primary were added up in one lump, people voting in the other in another lump. The same poll, just presented in two parts) the implication here is that the sampling itself probably wasn’t the problem or the Republican race would also have been wrong.

Secondly there is the interviewer effect in polling on races with a black candidate. There is a long history in the USA of polls in races between a white candidate and a black candidate showing the black candidate doing a lot better than they actually are, theoretically because people are worried that they might come across as racist if they say they are voting against the black candidate. Could this have happened in the the New Hampshire primary? It could have, but the evidence isn’t really there – PEW published a paper last year on the subject that showed yes, there was such a phenomenon in the 1980s and 1990s, but that in more recent contests between white and black candidates in the 2006 mid-term elections there was no such discrepancy. It looks like people are now more relaxed about race and voting. It’s also worth noting that if was this all down to the interviewer effect you might expect automated polls that didn’t use an interviewer to not show the same bias, or at least, to show less of a bias. Rasmussen, who use robocalls with a computer on the end of the line instead of a person were showing great big Obama leads along with everyone else. No, it’s the sort of explanation that poll watchers find fascinating, how people’s answers are biased by various different effects, but in this case I don’t think it is the explanation.

Thirdly, the turnout model. Here we bump into a lack of information to judge the polls on. In the UK likely voters are indentified in a very straightforward manner – pollsters ask respondents if they’ll vote. We don’t always believe them, you can tell ICM that you are 6/10 likely to vote and they’ll metaphorically stroke their chin and stick you in the reject tray, probably quite rightly so, but the methodlogy is very clear. In the the models pollsters use to identify “likely voters” are more complex and often factor in things like past voting habits and so on. In many cases the information on how exactly these calculations are done isn’t easily available so it’s hard to judge, equally a lot of the cross-tabs that would give us a steer on whether they matched the make up of the people the exit polls say actually voted aren’t freely available. In the event the turnout in New Hampshire was higher than expected, particularly amongst older women who backed Clinton – if the pollsters didn’t correctly get the turnout models right, that could be the problem.

Fourthly there is late swing. A lot of people look down on this as a rather poor excuse for getting polls wrong. In my experience most pollsters are pretty scathing about it when a rival uses it to explain why they predicted an election wrongly. That doesn’t mean we can discount such a thing happening – opinion swung rapidly to Obama after the Iowa caucas, in theory it could just have easily have swung sharply away from him.

There is some evidence on this front. The exit polls said 17% of people made up their minds on the day, that’s after the opinion polls had finished. 38% decided in the last three days (including a third of Clinton’s support), when many pollsters stopped work on Monday. In his article John Zogby says he’s used to seeing around 4% to 8% of people claiming they made their minds up on the day, so this does suggest an unusually volatile electorate.He also claims that the last day and a half of his rolling 3 day poll was showing very strong figures for Clinton. Rasmussen too did some late polling into Monday night and saw the trend headed in Clinton’s direction (though obviously not that much; they were still showing a 7 point Obama lead).

Gary Langer rebuts this by pointing out that, if you exclude all the people who decided on the day, the exit polls still show Clinton would have won by 2 points. It wasn’t just those late deciders who voted for Clinton, earlier deciders were for Clinton too. The problem with that logic is that most of the 17% of people who decided on the final day who to vote for weren’t sitting on their hands up until that point. Pollsters were showing around 5-7% undecided, leaving another 10% of people giving a voting intention that they didn’t finally decide upon until the day, in other words, two days earlier that 17% of voters who decided on the day could theoretically have been telling pollsters they were intending to vote for Obama in droves, but later changed their mind and narrowly backed Clinton.

What might have caused a big late swing isn’t really my bag, I’m not a commentator on US politics. There are obvious possibilities in the natural fading of the short term boost Obama would have received from his Iowa victory or the heavy television cover of Hillary Clinton coming close to tears in responding to a question and saying why the contest mattered to her, if a significant weakness to Clinton’s candidacy is her image as an unfeeling, calculating ambition machine, you can imagine how it may have made a difference.

“Late swing” feels like a thorough cop out, so I do hope that in later analysis people find a more concrete explanation somewhere, possibility in the turnout model, at the moment though I think it really could be as mundane as there being a late swing amongst a volatile electorate who saw a sudden glimpse of humanity in a hard-faced candidate.

UPDATE: Danny Finkelstein thinks its the spiral of silence, given that the polls only underestimated Clinton and no one else. The spiral silence is quite possibly contributing to it (Clinton was on the ropes and people were embarrassed to admit to pollsters they were still backing her when they thought everyone else was leaving the sinking ship), but the explanation is too straightforward. The polls had everyone else bang on but Hillary too low? Well, it needs to add to 100% so they must have been somewhere. In fact they were the undecided, remember that US polls do not repercentage polls to exclude don’t knows so these figures included around 5-7% don’t knows. This chimes precisely with the spiral of silence, people claiming they don’t know because they are too embarrassed to say Clinton. It chimes a bit too precisely though…we’d have to accept that all the undecided ended up voting for Clinton…which is stretching credulity a bit too far. Might well be a factor, but not an open and shut case.

UPDATE 2: More comment from Jon Cohen, polling director at the Washington Post, including opinions from Peter Hart who does the NBC-Wall Street Journal poll.