Yesterday’s YouGov poll for the Sun had the first Libya questions since the rebels entered Tripoli. Full tabs are up here.

Public opinion on how well the West’s intervention in Libya and on whether it was right or wrong for the West to intervene have predictably flipped. Support for the West’s intervention had been standing at an August average of 33% thinking it right, 44% wrong – that has flipped to 41% right, 35% wrong. 25% of people had been thinking it was going well, 51% badly – that has flipped to 52% well, 26% badly. 47% of people now think that David Cameron has responded well to the situation in Libya, 33% badly.

If Gaddafi surrenders, 58% want to see him sent for trial at the International Criminal Court, 26% think Libya should try him. If he is found guilty 33% want to see him executed, 49% given life imprisonment. 39% would be happy if Gaddafi was killed in the conflict, 38% would rather he was captured alive so he can be put on trial. Finally on Libya, only 17% of people think we should send in British troops to keep order under the new regime. 38% would be happy to send police advisors, 42% would be happy for us to send emergency cash, food and medical aid.

On the wider impact of the Arab Spring, 23% are more optimistic about the future for the Middle East, 35% are less optimistic. People tend to think events in the Middle East will result in it being more democratic and more respectful of human rights… but also think it will be less peaceful and more vulnerable to terrorism.

The Guardian’s monthly ICM poll is out (I’m not sure why it’s turned up at lunchtime – or perhaps I just missed it last night!). Topline figures are CON 37%(nc), LAB 36%(nc), LDEM 17%(+1), Others 10%. The Conservatives retain a one point lead. ICM do tend to show some of the most positive figures for the Conservatives (for reasons I’ll address below), but last month their 1 point Conservative lead did look like something of an outlier. It seems, however, that the difference is more systemic.

Now, looking at people’s reaction to this I’ve already seem plenty of comments remarking upon the big contrast between different companies figures – it probably deserves some explanation. Let’s start by comparing the sort of figures the different companies have produced over the last three months.

In their daily polls YouGov have been showing Labour leads of around 8 points, with the Conservatives firmly on around 36%, Labour on 42-44%, the Lib Dems on 9-10%.

Populus, who in most senses have methodology very close to that of ICM, have been showing the Conservatives between 34-39% (they dropped 5 points in their last poll, so it’s a big range), Labour firmly around 39-40%, the Lib Dems around 9-11%.

Ipsos MORI again have shown some variation in Conservative support, ranging from 32%-37% in their recent polls, have Labour more steady between 39%-42% and have the Lib Dems on 9-11%.

ComRes run parallel polls – telephone ones for the Indy and online ones for the Independent on Sunday. In their phone polls the Conservatives have been between 34-37%, Labour between 37-40%, the Lib Dems 11-13%. In their online polls the Conservatives have been between 36-38%, Labour have been between 37-40%, the Lib Dems at 10-11%.

The difference between an 8 point Labour lead and a 1 point Tory lead is large, but as Bob Worcester is want to say, look at the shares, not the lead which exaggerates variation. As you can see, with some variation and a couple of outliers like that 32% from MORI, the pollsters are largely showing the same pattern with the Conservatives, everyone has them at either around or slightly below the 37% they got at the election.

The big difference is the Lib Dems, where most companies have them around 10% or 11%, YouGov marginally lower, normally on 9% and ICM quite drastically higher, on 17%. For Labour, most companies have them between 37%-40%, the exceptions being YouGov who have them in the low 40s, and ICM who have them at 36%.

Now, one major reason behind the difference is topline adjustment – what happens to people who say “don’t know” when asked how they’ll vote. Pollsters treat these people in different ways. At one end of the scale, YouGov just ignore them; YouGov figures are based solely upon people who say how they would vote in a general election. Then we get pollsters who ask a squeeze question to people who don’t answer (are you leaning towards any of them, who would you vote for if it was a legal requirement). At the other end of the scale ICM (and, to a lesser extent, Populus) essentially make educated guesses about how these people would vote, and include them in the figures. Evidence from past elections shows that when push comes to shove “don’t knows” are likely to end up voting for the party they voted for at the previous election, hence ICM reallocate 50% of people who say don’t know to the party they voted for in 2010.

Almost by definition, this tends to be helpful to parties that have lost support since the last election, and harmful to those who have gained it. In this month’s poll it had a particularly sharp effect – before adjustment ICM’s topline figures were CON 37%, LAB 39%, LDEM 15%. The effect of reallocating don’t knows was to increase Lib Dem support from 15% to 17%, and decrease Labour support from 39% to 36%, producing a Tory lead.

Of course, that doesn’t explain all the difference. ICM would still be showing the Lib Dems on 15%, significantly higher than anyone else, and there would still be variation between the companies on other factors. There are various other explanatory factors at play – for example, I’ve seen it hypothesized that ICM’s question wording, which says “an election in your area” increases Lib Dem support. I am very sceptical of this explanation, but it is potentially a factor and is worthy of investigation. Another factor is likelihood to vote – most companies weight or filter by how likely people say they are to vote, YouGov only do this during election campaigns, when it reduces their level of Labour support.

Beyond that, there are probably factors connected with weighting – both the targets that people weight towards (primarily what assumptions they make about past vote and false recall) and also when the data is collected (YouGov and ComRes’s online polls can use stored data on panellists, polls conducted by telephone collect the data at the time the survey is conducted).

I draw no conclusions about what is right or wrong. When I first started this blog I always sought to explain the reasons behind the differences and let people make their own decisions, rather than say which polls I thought were right or wrong. In many cases, it is a philosophical difference, a case of polls measuring slightly different things – a YouGov poll is showing how people say they would vote tomorrow, an ICM poll is showing how ICM think those people would vote tomorrow. In other cases, some weighting targets probably are better than others! My sad conclusion after writing about polling for 6 years, however, is that most people tend to believe the poll they like the results from is the one to trust, and subconsciously interpret arguments about methodology to back up that preconception (not, I should add, very different from how we come to our opinions about anything else in life!)


It looks as though yesterday’s YouGov/Sunday Times poll showing a Labour lead of four points was indeed just a blip – tonight’s poll has topline figures of CON 35%, LAB 44%, LDEM 9% – very much in line with the average Labour lead of 8 points or so that YouGov have been showing for the last six weeks.

Survation have published a poll of Derby North and South Derbyshire constituencies for the Mirror and Progressive Polling, which shows a boost for Labour in both seats. Full tabs are here. The polling methodology itself was largely along ICM lines (telephone survey, weighted by past vote, ICM style weightings on likelihood to vote, and refusals and don’t knows reallocated according to how they say they voted last time).

In Derby North, currently a Labour marginal, the poll found figures of CON 23%(-9), LAB 51%(+18), LDEM 11%(-16), BNP 10%(+6), Others 6%(+3).

In South Derbyshire, currently a relatively comfortable Conservative seat, the poll found figures of CON 32%(-14), LAB 51%(+15), LDEM 9%(-7), BNP 1%(-3), Others 12%(+9)

The precise shares of the vote aren’t that interesting, given they are based on 174 and 149 people respectively, and hence have very large margins of error, but the overall picture is of a big swing towards Labour. Labour’s performance isn’t radically different from national polls, but there is a sharp drop in Tory support, something national polls aren’t showing. It implies that the Conservatives are doing worse in Derby than elsewhere.

Now, a plausible explanation is that this is connected with the Bombardier decision… it is certainly possible for large industrial closures to have big effects on particular seats (an excellent example is Redcar at the last election, where one assumes the closure of the steelworks was a factor behind the massive swing).

However, it pays to remember that correlation does not equal causality. This could be a Bombardier effect, it could be that the Conservatives are doing worse in a lot of urban seats, or in Midlands seats, or something entirely different. We don’t know. The rest of the questions are of no use in determining salience of the issue – questions of the “How likely is X to affect your vote at the election” pattern are worse than useless (they give false prominence to an issue with no requirement to balance it against other issues, or any measure of how likely people actually are to change their vote).

Of course, in practice we are probably years away from an election (in the Redcar example I quoted above the steel plant was mothballed a matter of months before the election) and there are likely to be major boundary changes in the Derby area (I’d expect Mid-Derbyshire to get the chop, with consequential knock on effects) anyway, but an interesting local straw in the wind nonetheless.

UPDATE: Unconnected to this (well, no more connected to this than every other post I make), there’s a very good explanation of sample error from Ben Goldacre here.

YouGov’s daily poll for the Sunday Times has topline figures of CON 36%, LAB 40%, LDEM 11% – it’s a lower lead for Labour than we’ve seen in YouGov’s recent polls, but I’ll just leave that with my normal caveats about not reading too much into a single poll. It may be Labour’s increased hackgate lead receeding… or it may just be margin of error, and we’ll find Labour’s lead back to around 8 points tomorrow.

There is not much change from last week in how the political leaders are perceived as having responded to the riots – 45% think Cameron has responded well, 49% badly (from 45% to 49% last week), 42% think Miliband has responded well, 41% badly (from 40% to 40% last week). The standard leadership ratings for Cameron and Miliband remain largely unchanged too.

Most of the questions are still riot related – Almost half (48%) of people think the sentences for rioters are about right, with the remainder more likely to think they are too soft (31%) than too harsh (14%). On the specific case of the two men given 4 years a piece for failing to incite riots through Facebook, 32% think the sentences were too harsh, but 50% think they were right and 13% too soft.

Looking at further measures that have been suggested, 95% would support making those involved help repair the damaged caused, 81% would support naming and shaming those under 18s convicted, 81% would support making those convicted apologise to their victims. 68% would support stopping the welfare benefits of those convicted. On the question of evicting people who are convicted of rioting from council accommodation, 62% of people would support evicting tenants themselves if they involved in the riots, but this drops to only 34% when asked about evicting families whose children were involved in the riots.

Looking at longer term responses to the riots, 56% of people would support the re-introduction of national service, with 32% opposed (there is a strong correlation with age here, two-third of over 60s would support it, under 25s are marginally opposed to it). A national citizen service, requiring compulsory community work for all young people, is more popular – 77% would support it with only 14% opposed. There is less support for the government promoting marriage in the tax and benefit system – 39% think it should, 48% think it should not be the government’s place to promote marriage.

Moving to the topic of tuition fees, only 29% of people think that a university education is worth £9000 a year. However, they are evenly split on whether this means people will be better or worse off financially from going to university. 40% think graduates will still be better off as increased salaries will outweigh the costs of going to university, 42% think graduates will end up worse off.

Finally, on trains 79% of people think current fares represent bad value for money. 47% think the government should maintain rail subsidies, even if this means larger cuts elsewhere. 24% think that the government is right to cut subsidies.

Full tabs are here.