Tuesday, September 27, 2011

Competing Ontario polls

Two new polls out in Ontario today ahead of the debate, one with the Liberals ahead, one with the PCs, so which to believe.

An Ekos poll had the Liberals at 34.9%, the PCs at 31.4% with the NDP at 24.7%.  However, Abacus Data had the PCs ahead at 37%, the Liberals at 33% and the NDP at 23%.  The only big difference is actually in the PC number but it is significant.

One way of verifying the credibility of a poll is to look at its internal subgroups.  There is a certain consistent pattern that reappears in poll after poll regardless of overall outcome or source.  If there is an anomaly it should be apparent.  Look on page four of the Abacus poll.  It tells us that the PCs lead among women and voters age 18 to 29.  So younger voters and women support the PCs almost to the same degree as the province as a whole.  However, there is absolutely no way that is true.  PC support is typically older and male to a much greater degree than we see in Abacus.  In the Ekos poll (see page 7) one sees the relative weakness of the PCs among youth and women, and one sees it over and over again in many others.

Abacus was attacked by Ipsos Research (the most accurate pollster in the May 2 federal election) for shoddy methodology (methodological snake oil is how they described it) earlier in this campaign. Abacus made a point in their release of emphasizing that they used a traditional ballot question on this poll (in response to the Ipsos critique).  TC thinks Abacus has more work to do.