What the…? How on earth did that happen?
When Paddy Ashdown was told the exit poll forecast of 316 seats for the Tories, he said he would publicly eat his hat if that turned out to be true. Actually it wasn’t true. The exit poll underestimated the full extent of the Tory triumph.
Why did the pollsters get it so wrong?
Here are five possible explanations:
- Shy Tories. In previous elections, the pollsters have found that some Conservatives are unwilling to admit which way they will vote. There is so much hostility to the Tories expressed in the broadcast media that some Tories fear they will be thought of as harsh if they say which way they will vote or might be verbally assaulted. The pollsters are meant to allow for this phenomenon but it is conceivable that they did not allow for it sufficiently. On the other hand, my own impression is that people have been more willing to say they are Tories in this election than they have been since the 1970s.
- Determined Tories. This was my secret hope before the poll, that the Conservatives were determined to get out and vote. They really believed with conviction that Miliband would be bad for the country and bad for their own taxation. Obviously this particularly applied to those facing mansion tax but also to those who thought the Tories had done well with the economy whereas the Labour might ruin the recovery. In contrast, those who said they would vote Labour might have been less determined to vote and less sure they were doing the right thing. Meanwhile those who have a greater tendency to vote Labour, are in the groups that are less certain to vote: the young and the less well-off.
- Tactical voting. This is the first election I remember where a newspaper has given detailed instructions, seat by seat , on how to vote tactically to keep out Labour. The Daily Maildid it the day before the election and the day of the election itself. The Daily Mailprobably has the biggest readership of people who actually go out and vote. The recommendations were not one way. They included recommending voting for Clegg in his seat, for example. But often it consisted of recommending UKIP supporters to vote Tory. Tactical voting might have made a difference.
- Last minute decisions. It is conceivable that people changed their minds to vote Tory when they actually reached the ballot box. But the Ashcroft exit poll indicated that relatively few Tory voters decided to vote that way in the final 24 hours. So that seems a less likely explanation.
- Faulty polling techniques. The online polls tended to show weaker Tory support. It is easily possible that the pollsters underestimated the extent to which elderly Tory voters are not online. But even the phone polls got it wrong. So that does not seem like the full explanation.
Overall, I guess that the most likely explanation is a mix of the above with the most important ones being 2 and 3: determined Tories and tactical voting.
See James Bartholomew’s new book, The Welfare of Nations, here.