Thursday, December 08, 2005

Contradictory Messages in Polls

Since most polls have reported the Liberals to be leading, there is a general impression of not much happening in this campaign. It has had a low key flavour.

However, the polls are giving quite contradictory messages. I think this deserves more attention. An Ipsos-Reid poll completed last week did have the Liberals ahead but only by two points, 33% to 31% over the Conservatives with the NDP at 17%. Once the regional numbers are crunched through my forecasting model we find a Conservative minority government with Mr. Harper’s party winning 115 seats to the Liberals’ 97 and the NDP’s 29.

Contrast that with today’s SES poll. It has the Liberals ahead overall 40% to 26% with the NDP at 18%. The data translate into a Liberal majority government of 168 seats with the Conservatives’ 57 seats apparently putting them in third place behind the Bloc’s 59 seats, with the NDP at 24 seats.

The Globe’s Strategic Counsel numbers are in between.

The difference cannot be explained by the half a week lag between the two surveys. I continue to believe current preferences are quite weak, and what we are really seeing is differences in methodology. I think it likely that one pollster or the other has got it wrong (or both), but there is no immediate election to tell us which one with any certainty.

Personally, the numbers I find hardest to believe in the two surveys are the SES numbers for Western Canada, which report a massive swing away from the Conservatives to the Liberals and the NDP. In 2004 the results in the West were Liberals 26.8%, Conservatives 45.5% and the NDP 20.4%. Today’s SES poll the West region preferences are given as Liberal – 35%, Conservative – 36% and NDP – 24%, quite a shift.

The polls should converge by the end of the campaign.

Addendum: Paul Wells seems to have spotted this emerging problem. A new Léger Marketing survey appears to support SES. However, Léger has uniformly delivered numbers very favourable to the Liberals so I don't find their results all that surprising. Their western numbers show a significantly smaller shift to the Liberals than SES.

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