Is it time for punters to cash in on the annual polling quirk?

On the face of it today’s YouGov poll is great for Labour, a warning to the Tories and bad news for the Lib Dems who have seen all their gains of last week just wiped out.

In fact polls bang in the middle of conference season are usually totally misleading and merely reflect that whoever was on most recently was getting an extra publicity boost. This is largely because of the broadcasting rules that mean that the national TV and radio stations suspend their normal news judgements for three weeks. Extra time is devoted to to the party conferences which affects the opinion polls.

Things generally get back to normal in late October or early November.

Thus two years ago Labour suddenly found itself back level pegging with the Tories after Tony Blar’s final conference as leader. Before the conference the Tories had been 7% ahead; then it got to even; and then at the end of October 2006 the Tories were back with a 7% lead once again.

Last year we had the rapid change in the polls when an 11% Labour lead dropped by seven points the week afterwards before Gord made his general election U-turn. In 2005 Labour’s YouGov lead dropped by seven points between the immediate post-conference poll and the one in November.

So if the latest poll leads to the Labour spread price moving up and the Tory one moving down I’ll be back in the market cashing on on this annual polling quirk.

UPDATE: Anthony Wells makes this point about conference polls on UK Polling Report:-

“To see how ephemeral they can be we only need to look at the Lib Dem score in this poll. The YouGov poll conducted after their conference put them up 4 points to 20%, their highest score for years. This poll puts them back down at 16%, where they were before the conference season began. We’ll know the real position after all three conferences and all three conferences bounces have come and gone.”

My guess, also, is that the vast majority of those in the YouGov surveys filled in their online survey forms on Tuesday in the immediate aftermath of the speech – not yesterday when Ruth Kelly was dominating the politics news.

Mike Smithson

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