Sunday, May 25, 2014

Polling and the Ontario Election

Six companies have released public opinion polls for the Ontario election,t hree polls each from EKOS, Forum and Ipsos and one each from Abacus, Innovative Research and Oraclepoll Research.  The results are all over the map.  Someone is used a flawed methodology.

  • The Liberals have ranged from 30% to 41% - 11 percentage points
  • The PCs range has been 30% to 42% - 12 percentage points
  • The NDP range has been 19.9% to 28% - 8.1 percentage points
  • The Greens range has bee 3% to 11.9% - 8.9 percentage points

  • Ipsos has consistently had the lowest numbers for the Liberals and the highest for the NDP and among the highest for the PCs
  • EKOS has had the highest numbers for the Greens but the lowest for the PCs and the NDP
  • In the last two polls Forum has had the highest Liberal numbers

Out of 12 polls:

  • 6 have the Liberals leading - May 1, 6, 12, 15, 20, and 23
  • 5 have the PCs leading - May 3, 5, 9 , 14 and 21
  • 1 had the Liberals and PCs tied -  May 16th
In theory differing methodologies might show similar trends in the election, but there is not enough data to show trends given the large variations.  There might be a small downward trend for the PCs and upward one for the Liberals, but that only shows up with any clarity in Forum.   Clarity is really the wrong word with only three data points.   The variations within the results of the three companies is large enough that we need more polls.    

The differences between companies is big. Last week Ipsos released a poll on the 21st and Forum on the 20th.

Company Libs  PCs NDP Others
Ipsos    31   35  28   6
Forum    41   34  20   5
Diff     10    1   8   1

Clearly to have such dramatically different numbers for the NDP and Liberals means someone did something wrong.   The difference is so large that even if the "correct" answer were in the middle these would both be one in a hundred polls.     If one of them is correct, or close to correct, the other one is fundamentally wrong.

I have no idea who is correct, or if anyone is correct.   

When we at in EKOS, their May 23rd results for the NDP are close to the Forum results, but their PC results are lower than the other two and with the Liberals they are in the middle.   

In my opinion EKOS does a good job of getting a good representation of what the public thinks but those who vote in the election are not the same as the public overall.  I think they tend to get results too high for the Greens and too low for the right.

In my opinion, Forum tends to get respondents to their surveys that are older than the population but they might reflect the voters more accurately.  Forum often releases a lot of detail for their surveys and in the past I have seen them have way too many 55+ in their survey.

When it comes to Ipsos, I do not have a clear sense about them.   I have from time to time seen them trend higher for the right of the spectrum and low for the Greens than other companies at the same time.

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