Wednesday, April 27, 2011

Memories of recent third party surges: U.K. election 2010

A third party surges, bumping a longstanding rival party into third place for the first time in a country's recent memory. The third party surge is driven by a popular leader who performed well in televised debates. The headlines were dramatic. Sound familiar? That was the story of the Liberal Democrats in the U.K. election of 2010. When election day rolled around, however, the surge did not hold up:
The final results in Great Britain are CON 37%, LAB 30%, LDEM 24%, Others 10%. Seats are Conservatives 306, Labour 258, Liberal Democrats 57, Others 28. The MORI/NOP exit poll, despite initial scepticism when it showed the almost total disappearence of the Lib Dem surge, turned out to be pretty much spot on. However, this means the final polls tended to call the Lib Dems wrongly.
Ben Page and Martin Boon have both already commented to Research Live – Ben says “On our final poll for the Evening Standard on Wednesday, we had 40% of Lib Dems saying they might change their mind. We’ll all want to look and see what we can do about soft support for the Lib Dems, we’ll have to find a rational and reasonable way of dealing with it rather than just saying Lib Dems tend to overstate. We will all be looking at certainty of vote, voting history – the surge was partly younger people – and late switching, things like that. The Lib Dems were most likely to say they would vote tactically. So the support was there but it didn’t actually manifest itself in votes on the day – Lib Dem support was slowly deflating after initial Clegstacy and on the day fell further.”
The final poll numbers just before the election reproduced above don't capture the heights of the Lib Dem surge, who were even in first at one point.

From a later analysis in July 2010 by a pollster and a professor, they point to something called "Shy Tory syndrome" that has been known to pollsters in the U.K. but which may have been manifested in the 2010 election by a "Shy Labour syndrome" instead:
"...differential failure to declare their voting intention by those who in the event vote for one party rather than another, perhaps because they feel that their choice of party is currently unfashionable. [...] This time it seems to have been voting Labour that was regarded as unfashionable. In 2010 no fewer than one in five of those who actually voted failed to declare their voting intention when interviewed by ICM for its final poll – and they were nearly twice as likely to vote Labour as Liberal Democrat. Although ICM’s final poll prediction (unlike many others) included an adjustment that took into account evidence that Labour voters were apparently particularly reluctant to declare their intentions, that adjustment may not have been sufficient to take full account of what actually happened."
And UK polling report again:
So, taking all those into account, there is no clear reason for the Lib Dem overestimate in the pre-election polls. My guess is that a little bit was down to late swing, with other bits down to disproportionate response from Lib Dem supporters during the enthusiasm of Cleggmania, and pollsters having samples that are rather too well educated and interested in politics. As I’ve said above though, actually proving this is an entirely different matter!
Offered as something to think about as we head into the final days of this campaign. The U.K. election also turned into a bit of a wild card race and ended up in this surprising result that was missed by the pollsters. The comparisons aren't entirely neat of course. And, I'm sure this can't happen here...right?