Friday, April 26, 2013

British Columbia provincial election "swing-o-metre"

British Columbians head to the polls next month (May 14) to elect a new government. In the past, I have made provincial election predictions, but unfortunately due to my new position at Probit Inc. I will be holding off on making predictions, due to possible conflict of interest purposes. However, I will be making various geography related posts in having to do with the upcoming election, including projections based solely on published polls, without factoring in any hearsay like I have done in the past.

Today, I take a look at the B.C. “swing-o-metre”, a simple measurement tool that shows how much swing is needed for the Liberals or the NDP (B.Cs two main parties) to win a seat. A swing is a calculation that is the average change between the Liberals and the NDP. For example, the most recent Ipsos-Reid poll shows the NDP at 48% and the Liberals at 29%. For the NDP, that would be an increase of 6% from their showing in the last election in 2009. For the Liberals, that would be a decrease of 17%. If you average those two numbers you get about 11.5%, which would be the swing from the Liberals to the NDP.

The chart on the left shows the swing needed for either party to win each seat from the result they got in the last election. For example, for the Liberals to win the riding of Surrey-Green Timbers, they would need a 24% swing from the NDP. On the other extreme is the riding of West Vancouver-Capilano which would require a 26% swing from the Liberals to the NDP in order for the NDP to take the riding. This swing-o-metre works because all but one seat in the legislature was won by either party in 2009. One riding, Delta South was won by an independent, however I kept that riding on the chart to show how much the NDP would need in order to get ahead of the Liberals there (but not necessarily win).

In the 2009 election, the conservative leaning BC Liberals, lead by then Premier Gordon Campbell won a majority of the province's 85 ridings by winning 48 seats to the N.D.P.'s 35. (As mentioned, 1 seat was won by an Independent). Since then, Campbell's government became very unpopular, and he resigned. He was replaced by Christy Clark, who as of yet has been unable to rescue the party. During her reign, the province has seen the rise of the even more right wing Conservative Party, which had been a fringe party. It is now lead by former MP John Cummins. While the new Conservatives may not win any seats, they are polling in the low teens, and that vote is coming straight from the Liberals. However, even if the Liberals and the Conservatives were a united force, they still wouldn't match the polling the NDP is at. The NDP is at historic highs in the polls, led by popular leader Adrian Dix. Most polls show the NDP in the mid-40s, and the Liberals in the high 20s. There is also the BC Green Party, which is polling around the level of the Conservatives.

The most recent polls, from last week show a 7-12% swing from the Liberals to the NDP from the last election. According to the swing-o-metre, this would give the NDP 55-65 seats, a strong majority. The swing-o-metre also shows that the NDP needs only a swing of 1.93% to get a majority of the seats (43). This swing would give them the ridings of Maple Ridge-Mission, Cariboo-Chilcotin, Saanich North and the Islands, Oak Bay-Gordon Head, Kamloops-North Thompson, Burnaby North, Burnaby-Lougheed and Vancouver-Fraserview. To get to those 55 seats, the NDP would also win Vernon-Monashee, Surrey-Tynehead, Vancouver-Point Grey (Premier Clark's riding), North Vancouver-Lonsdale, Chilliwack, Port Moody-Coquitlam (a riding they hold now, thanks to a by-election win last Spring), Penticton, Prince George-Valemount and Parksville-Qualicum (securing a sweep of Vancouver Island). Of course, this only assumes a province-wide uniform swing, which we know wont actually happen. But it's a rough guide to see what riding's are in play. 

Swing-o-metre map. The darker the riding, the larger the swing necessary for the opposing party to win.


  1. Swingometers work best where there are only 2 real parties competing. BC might actually be one place where it might outperform my ratio method - which itself does best when there are "2.5" parties.

  2. Interestingly enough, my method shows the final Liberal riding (on this list) to remain Liberal as Vancouver-Langara; which is also what the swingometer shows.

  3. Yes, this only works with 2 parties, so just BC, SK, NB (maybe not next election), PEI and MB (save for one seat). Maybe I will develop a swing-o-metre triangle for ON, NL, & NS (and maybe QC)?