Sunday 14 July 2019

Which Pollster to Believe?

Polls can be confusing. Let's consider two from the end of this week. According to the latest from YouGov, the Tories lead on 24%, the Brexit Party on 21%, Labour on 20% and the LibDems 19%. We're still very much in four-party territory and the crisis of the two-party system we entered into after the EU elections hasn't gone away. But if you look at Survation's latest, we find a different story. Here, Labour is on 29%, the Tories 23%, BXP 20%, and the LibDems on 19%. Who's right, and who should we take with a pinch of salt?

There are two ways of looking at this. We can compare the polling with recent findings from other companies, and we can look at the methodologies employed. Looking at the mood music coming from other pollsters, only one other has been out out recently and that was from BMG Research. It had the Tories on 28%, Labour 27%, LibDems 18%, and BXP 14%, and its fieldwork was done the week before last. Not much to go with then. One might suppose a drift away from four-party politics over time since the EU election lies a month or so behind us, and the underlying political economy that gave us the 2017 election result hasn't gone away, but equally one could counter that the tedious Tory leadership election and the total dominance of everything by Brexit ensures the parties defined by the referendum - the LibDems and BXP - remain viable options. The fact two polls support the first proposition while another provides succour for the second mean neither position can be affirmed with any confidence on the basis of numbers alone.

We're going to have to look at methodology then. The case for YouGov is of all the polling outfits, in the run up to the EU elections they were consistently the outliers. For instance, in the last round before polling day YouGov had Labour on 13%, the Tories 7%, LibDems 19% and BXP 37%. In the event they massively overestimated Nigel Farage's party (it got 30.5%) but were the closest on the other parties. Compare this to Survation (23%, 14%, 12%, and 31% respectively) and BMG (18%, 12%, 17%, and 35%). YouGov come away smelling of roses and proved outliers aren't always wrong. And yet, if we wind time back a little bit, in GB-only polling for the 2017 General Election YouGov tanked with a 42% Con, 35% Labour eve-of-poll forecast, BMG 46% vs 33%, and Survation 41% vs 40%. BMG was nowhere, YouGov closer on the Tories, but crucially Survation was almost on the nose for Labour's vote.

To make sense of this we need to remember that the EU elections are second order elections. In political science terms, these tend not to matter so much to voters vs first order elections: i.e. ones that determine the government, a general election. And so we see a number of effects: turnout is usually depressed, and punters are more likely to stray from their normal voting behaviour and vote as a protest or go for a party closer to their political heart's desire. It's something we see in every by-election, be it parliamentary or for the local council, and certainly helped explain the result in Peterborough. There is also another oft unremarked effect. We know older people generally speaking are more likely to turn out than the young, with pensioners the most likely of all. This is doubly the case when it comes to second order elections, so it tends to skew toward their proclivities. YouGov polling weights its results to recognise this differential turnout by age, hence we find their massive overestimation of BXP's vote but an accurate forecast of Labour's support. Survation tend not to weight theirs in the same way, which meant they were more sensitive to the movements of younger voters in 2017 and more or less on the money.

What does this mean for Westminster intention polling now? Well, it all depends on what the next general election is going to be like. As Boris Johnson is odd on to win the Tory leadership, we know what his strategy is: ramp up the Brexit rhetoric, dribble some drivel about patriotism, and try and remake the coalition of voters Theresa May pulled together by squeezing the Brexit Party. This is not without difficulties and, if you want to be mischievous, it more or less amounts to a 35% strategy - just enough to get over the line in the context of a split electorate. But by pursuing a polarising electoral strategy, despite the usual tricks, Johnson runs the risk of uniting voters behind Jeremy Corbyn which, among other reasons, is what happened last time. When turn out is up, the differential age effect is depressed, which favours Survation. If the public look disengaged and nonplussed, then YouGov's methodology and polling has more chance of being right. Our job then is to mobilise, mobilise, and mobilise. An election could only be a couple of months away, and Johnson is both a known quantity and completely beatable.

3 comments:

Phil said...

No sooner had I finished writing this and ComRes are out with a new poll, which can be viewed here. A four point lead for Labour.

Speedy said...

Here is the poll of polls

https://britainelects.com/polling/westminster/

Labour 24%
Conservative 23%
Brexit Party 21%
Liberal Democrat 18%
Green 7%

This seems as good a likely reflection of voting intentions as any. In reality, this puts the pro-Tory Brexit vote on 44 per cent. Will hardcore Brexiters stick to Farrage and risk splitting the vote? I doubt it. More likely the Lib Dem's (and Greens) will split the Labour vote. If there were two parties there would be a 49-44 split to remain, which seems to reflect the national mood. Tactically, however (and in terms of past history) it seems far more likely that the Remain vote will be more rigid than the Leave, particularly given Labour's continuing ambiguity on Remain.

Of course, anything is possible, but I think as things stand (ie, Brexit Boris v Agnostic Jeremy) Boris wins hands down with (at least) a 20 seat majority, more like 80-100. How different things could have been had Labour chose Yvette (your first choice, if I recall) - cripes, we might not even have Brexit.

Boffy said...

The Brexit company is a fantasm that will evaporate as soon as Johnson is Tory Leader and steps up his Trumpian right-wing populism, and hard Brexit stance. That gives the Tories over 40%.

Given the real division in society has assumed the form of Leave v Remain the only way to beat the Tories is to adopt a hard Remain position. The obvious beneficiaries are the SNP. If Labour is to win in England and Wales it needs to adopt the hardest of hard Remain positions, arguing not for a second referendum, but for Revoking Article 50 outright.

Labour should be campaigning for a General Election in which it would argue that Brexit is reactionary and that Labour would revoke Article 50 if that had not happened by then. Labour should commit to taking Britain back into the EU if the Tories have taken Britain out.

In fact, when the next General Election comes the only party having a chance of winning a majority is going to be one committing to being in the EU including rejoining if necessary, because the changing demographics of Britain means that the majority for EU membership can only continue to grow from here, as all of the old Tories who voted for Brexit die off.