What I wrote at Lib Dem Voice

February 20, 2007

The art of spurious opinion polls

I’m a self-confessed opinion poll-geek, as regular readers may have garnered. But I have had my fill of ‘what if’ polls making psephologically spurious claims to predict what might happen if/when Gordon Brown faces up to David Cameron and Ming Campbell.

The latest (I’m sure you’ve seen) dominates today’s Grauniad front page - the headline screams, Brown v Cameron - exclusive poll puts Labour 13 points adrift. The question which prompts this hyperbole asks how the public might vote if Mr Brown led Labour, the Tories are led by Mr Cameron, and Sir Menzies leads the Lib Dems.

Astute readers will have noticed a small flaw: one of these people currently does not lead his party. What ICM are in fact asking is: how well do you think Gordon Brown might do a job he’s not currently doing? To read anything into the answer, other than that the Chancellor currently suffers a PR deficit, is plain silly.

Opinion pollsters often defend their claim to represent a science by pointing out (quite rightly) that all they can do is take a snapshot of public opinion; that they can’t predict the future. But they do their art no good by asking questions which seek to anticipate the future. Especially when they know such polling will be spun by newspapers with their own agenda.

1 comment:

Ken said...

I suspect, though, that these polls are useful in one respect, in that they give us a good indication of public opinion on the political figures concerned. Presumably, the first question is the usual "Who would you vote for in a general election tomorrow: Labour, Conservative, Liberal Democrat, Other?"

But for the second question, the specific person in question is linked with the party. That suggests that Brown and Campbell have negative associations compared with their party overall; Cameron has a positive one.