Worcester's Weblog - Shy Tories?
MORI chairman Sir Robert Worcester analyses the latest opinion poll data.
So far, 16 days into this election I must have heard/read the words "in 2001 the polls overestimated the Labour vote" scores, in not hundreds, of times over the last four years.
These comments have reached a crescendo during the first fortnight of this election. Few of these commentators and interviewers have acknowledged that we have taken steps to take account of the lower turnout among Labour supporters in recent elections. But to what effect?
Today's Sun Newspaper reports the latest MORI poll, taken among a national sample of 1,001 electors by telephone. The voting intention figures reported on those who said they were "absolutely certain to vote", 593 electors, 59%, (which happens to be the turnout in the 2001 General Election), were Labour 39%, Conservatives 32%, Liberal Democrats 22%.
Among those giving a voting intention, whether 'certain' of not, 722 people, the shares were Labour 41% (+2), Conservatives 28% (-4), Liberal Democrats 22% (nc).
The cause of the difference? Three in four (75%) Conservative supporters said they were "absolutely certain to vote", while fewer, 62%, of Labour supporters were so sure, as did 67% of Liberal Democrats.
In 2001, MORI reported 45% Labour, 30% Conservative in our eve of poll survey. If these correction factors had been applied in that election, Labour would have been reported to have 43%, the Conservatives 34% and the Liberal Democrats 18%.
The result on the day was in fact Labour 42%, Conservatives 33%, and the Liberal Democrats 19%. One point out for each party, well within the usual +/- 3% quoted for sample sizes of 1,000 interviews, even better considering the effective sample size of c. 600, say +/- 4%. Of course the acid test will be on May 5th. But if the past is any guide, the easy critique made by both naпve interviewers and pundits who should know better, should be reconsidered, and their cacophony reduced. At least until May 6th, when we'll all know if by applying this we've introduced some other source of error.
But then if it was an easy business, everybody would be in it, instead of being our self-appointed critics, without the responsibility of meeting unreasonable expectations themselves.
