Tuesday, May 14, 2013

British Columbia provincial election projection maps


Today is the day of the B.C. provincial election, and unfortunately, unlike past provincial elections, I had not been doing routine projection. However, I couldn’t let the election period go by without doing some sort of projection, so I have crunched the most recent polls to come up with a purely math based projection to see how the results tonight may turnout. In previous projections, I have liked to factor in what I like to call “qualitative” data- that is taking a look at what people are saying about various districts to get a sense of how they may differ from normal trends. In my math-based projection, I have ignored this completely. For example, while I believe the Greens will win the riding of Oak Bay-Gordon Head, my math based projection shows otherwise, because I have purposely not taken into consideration local factors this time. I want to be able to show a transparent projection this time.

For my projection, I have taken a look at the most recent polls from Justason, Ipsos-Reid, Forum Research, Hill & Knowlton and Angus Reid. These are the only pollsters that had regional crosstabs. The most common regional breakdowns used are “Metro Vancouver”, “Vancouver Island” and “Interior”. So, I have taken an average of the regional breakdowns for those three areas (taking out the polls that don’t use those regional breakdowns) and looked for the difference between the 2009 provincial election results in those regions and the average:


Liberal avg.(change from 2009)
NDP avg. (change from 2009)
Green avg. (change from 2009)
Cons avg. (change from 2009)
Other avg. (change from 2009)
Interior
38 (-8.8)
38.5 (-0.4)
10.5 (+2.6)
9 (+4.0)
5 (+3.5)
Vancouver Island
29.2 (-9.5)
44.4 (-5.6)
18.4 (+8.0)
7 (+6.7)
1.8 (+1.0)
Metro Vancouver
34.5 (-13.9)
47.55 (+6.4)
9.6 (+2.2)
5.45 (+4.8)
2.8 (+0.6)

Next, I factored in these swings to each riding in their respected three regions. For the Liberals and the NDP, I also factored in the trend between the 2005 and 2009 elections. So, if a riding is trending Liberal, that riding will not see as adverse swing as a riding that is trending NDP (and vise vera). Whatever percentage I got from this, I used in my projection. It’s not the best way of doing it, but at least it will give a good idea of how the election will shape up.

Here is the map:

Math based projection


For the record, this gives us 53 NDP seats, 30 Liberals and 2 Independents. Seats that were decided within 5% include Boundary-Similkameen, Cariboo-Chilcotin, Chilliwack, Kamloops-North Thompson, Comox Valley, Oak Bay-Gordon Head, Langley, North Vancouver-Lonsdale, Port Moody-Coquitlam, Surrey-Panorama, Peace River North and Vancouver-Langara. It is safe to say that most of these ridings will be one’s to watch tonight. The two independent seats are Delta South and Peace River North. Delta South was won by an Independent last election, and the Independent who did quite well in Peace River North in 2009 is running again.

But of course, using math is not the only way to make an election projection. I also scoured the internet last night to find what other projectors were saying. I compiled the results, and made another map based on their cumulative projections. I took a look at electionpredictions.org, The Tye, Teddy Boragina, BC Iconoclast, threehundredeight.com, Global TV, tooclosetocall.ca and BC2013.com. It should be noted that some of these projectors may have made predictions this morning that may affect the map. But, it does serve as another useful tool in predicting the election. Because I used 8 predictors, there were several ridings that were evenly split in terms of which party was projected to win. These were Prince George-Valemount (4 NDP, 4 Liberal), Cariboo North (3 Independent, 3 Liberal, 1 NDP, 1 too close to call), Chilliwack (4 NDP, 4 Liberal), Oak Bay-Gordon Head (3 NDP, 3 Green, 1 Liberal, 1 too close to call) and Vancouver-Langara (4 NDP, 4 Liberal). My math based projection has these ridings going the following:

*Prince George-Valemount: Liberal (43%-36%)
*Cariboo North: NDP (50%-36%) – the sitting MLA, an independent and former NDPer complicates things.
*Chilliwack: NDP (36%-32%)
*Oak Bay-Gordon Head: NDP (39%-37%) – a strong Green campaign complicates things
*Vancouver-Langara: Liberal (45%-41%)

Aggregate prediction map from 8 predictors


The cumulative projections also differ from my projection in a number of ridings. In addition to the ties, these include Vernon-Monashee (I have going Liberal), Chilliwack-Hope (I have going Liberal, but the riding does have an NDP MLA thanks to a by-election), Comox Valley (I have going Liberal) and Parksville-Qualicum (I have going Liberal). Really, there is not much difference, but it does look like other projectors are slightly more NDP-friendly in terms of their predictions. In looking at the cumulative results, there are 5 ties, 2 ridings to go independent, 25 Liberal and 53 New Democrat seats. Oh, and for the record on both these maps, Liberal Premier Christy Clark loses her seat. 


Polls will be closing at 8PM Pacific tonight (11pm). Expect some commentary from me on my Twitter feed. I just hope it doesn’t go too late into the night!

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