Beware the over-prompting of Mark Reckless and UKIP in Rochester by-election polls
"@cgi247: Mark Reckless on the campaign trail in Rochester #UKIP pic.twitter.com/qUcjwth85k"
— Mark Reckless (@MarkReckless) November 4, 2014
The intro to voting questions in the Ashcroft poll
As you may know, the Member of Parliament for Rochester & Strood, Mark Reckless, has announced that he is leaving the Conservative Party and joining the UK Independence Party (UKIP). He has therefore decided to resign as an MP and to fight the resulting by-election in Rochester & Strood as the UKIP candidate. Many local people are saying that they probably won’t vote at all in the by-election, while others say they definitely would vote. Please say how likely you are to vote in the by-election, when it happens?
if under-prompting depresses the shares then over-prompting could have the opposite effect
Much has been written in recent months about prompting in voting intention polls. UKIP has argued strongly that it should be treated on the same basis as the traditional three main parties and that those polls that don’t do this are understating its position.
-
But could the opposite be happening in Rochester by-election polls? Could the form being used by pollsters actually be over-emphasising UKIP and its candidate?
Above I have reproduced the precise wording that Lord Ashcroft used in the latest Rochester poll. This is the very first question that participants are asked and it very much sets the scene for the questions that follow. Voters are reminded that Reckless is the incumbent, UKIP is name checked twice, and no other candidates are mentioned. The impression is this is all about Mark Reckless and his decision to switch parties.
My reading is that opening in this way could possibly could cause participants to overstate their voting certainty and then to respond to the voting question that follows on their view of the Reckless decision.
A more neutral, and possibly a better way to start, would be simply to say “As you may know there is a by-election in Rochester and Strood on November 20th. Please can you say how likely you are to vote”.
An interesting feature of the poll is that a second voting intention question, asking about the general election, was put and this produced very different numbers from the by-election one. The Tories were 1% ahead suggesting that if Mark Reckless won next Thursday he could lose next May. In that question there was no reference to Mr. Reckless/UKIP or any of the other parties.
It should be noted that similar question formats were used for Clacton and the polls were broadly in the right area. But that outcome was so much more clear cut right from the start and Carswell had a very different relationship with his constituents.