Thread by @ssolyom

The problem with polls, poll aggregators, and people who obsessively follow their ups and downs emotionally:
In brief--can't trust 'em
Longer answer--let's test out some hypotheses... /2

So folks are looking at today's aggregate polling and (Liberal supporters) are shrieking about how the CPC has suddenly surged. Well, first, that isn't what the aggregators (newsinteractives.cbc.ca/elections/poll… and 338canada.com) seem to be showing. I read them as saying... /3

3/ ...that both parties have come down, LPC significantly more, and NDP and Bloc have risen. Not hugely though. With these numbers, and given regional breakdowns, which is a crap shoot except in AB/SK, this puts them within about 20 seats of one another. Let's look at that... /4

4/ ...So, what happened? Well they both had 6 polls to add to the mix since Wednesday. Forum, Mainstreet, Nanos, IR, Leger and Angus Reid. These are all over the map, from 28/35 L/C to 31/31/ to 35/31. Let's set aside the NDP/Bloc for now. It's critical to weight the... /5

5/ ...accuracy & reliability of these polls, which both Eric and Philippe do quite well. I'd argue against weighing Angus Reid so strongly, because it's an internet panel, and historically skews 4 points or more to the CPC. Still, these numbers drive this story. But... /6

6/ ...what about the other numbers? And what about the trends, if any? Let's start with the latter. A single day or two of good or bad polling is not a trend. So even if the poll accurately captures this snapshot, without further polls it's mute. And what about those other... /7

7/ ...numbers? Well, they show a trend that is more or less steadily showing a very slow (glacial) Liberal advantage emerging. I tend to discount both AR and Forum, and they are clear outliers amongst general agreement otherwise. Leger is probably more accurate, but... /8

8/ ...it's not easy to say because they don't poll as often. They were at 34/34 last time, 31/31 now. There's movement, but it's unclear how great. The rest generally agree. So, first piece of advice is "keep calm and don't let the polls get you down". But, as I posted... /9

9/ ...earlier, there is another dynamic that the raw national numbers don't show. According to both aggregators, CPC vote share in AB/SK is 65% and growing or static. No matter what happens, it seems at least 60% is now baked in. What does that mean? Well here are the... /10

10/ ...relevant numbers.
Population AB/SK <> 5.3 million
Population Canada <> 36 million (2016 numbers)
So 65% of 5.3 = 3.4 million
If the CPC nationally has 32% of 36 million = 11.5 million, then ROC number is CPC at 8.1 million, or 26.3% of population... /11

Doing the same math on the LPC numbers yields an ROC number of 34.9%. Now as far as seats are concerned, the picture is a lot fuzzier--some ridings are very close, others blowouts, so it doesn't translate exactly into the same proportion. But still... /12

12/ ...a close race nationally favours the Liberals. What will be critical, as many have stated repeatedly, is how ON, QC and BC breakdown, because that can alter quite a bit.

Whew. Long way of saying... take a pill!

(@EricGrenierCBC or @Qc_125 please correct me if needed)