I recently looked at possible stop-gap PR systems, ones that could be implemented for a single election as a temporary replacement for first-past-the-post (FPTP). I thought it would be fun to run the 2017 election under the Top Candidates PR system.
Based on the popular vote, the parties in the 2017 BC Provincial Election should have had:
The BC Conservatives just narrowly missed out on a seat due to their share of the popular earning them 0.4611 of a seat (so it rounds down rather than up). The BC Libertarians similarly just missed out, by earning 0.348 of a seat.
There are a couple of ways that Top Candidates PR could be run, but I’m choosing to do it the following way:
– calculate how many seats each party should get based on the popular vote (look at the most popular unsuccessful independent candidate(s) too, and see if they managed to lose their riding but nonetheless come a close enough second to earn a round-up rather than a round-down, which is theoretically possible)
– once any independent candidates are assigned, assign seats to parties starting with the party who was most underrepresented by FPTP, and work towards the one that was the most overrepresented
– adjust so that every riding has only one representative, favouring the most underrepresented party
So we start with the 15 Greens. This could be done by either raw vote totals or it could be done by percentage of the votes in each riding, and there are advantages to each. Let’s look first at by raw votes:
First we do the BC Green Party as they were the most disadvantaged winners in the election. The Greens would start with the three ridings they won under FPTP, and to that we could add the 12 ridings they did the best in without winning:
West Vancouver-Sea to Sky
Powell River-Sunshine Coast
Then we move on to the NDP, as they were second-most disadvantaged by the results and we give them the 32 ridings they won that we didn’t allocate to the Greens:
Then we top them up with the ridings they got the most votes in despite losing.
As we can see, under this system the NDP only need to be given four ridings that they didn’t win, all of which they did well in and and one of which they only lost by 87 votes (Coquitlam-Burke Mountain). Most of the riding transfers were urban ridings, because they were generally more competitive in this election.
That leaves the BC Liberals with the remaining 36 seats, all of which they won under FPTP.
It does occur to me that this system might be better off to use the percentage support rather than the raw vote totals. Ridings with high voter turnouts are potentially less likely to elect their preferred candidate because all parties may have done well in that riding.
Alternately we could base all transfers on how far behind the winner the candidate was on a percentage basis, and this too would lead to mostly urban ridings being transferred due to their competitiveness.
However, we might base riding transfers on how far behind the winner was on a raw numbers basis. This would mean that the Greens would be receiving some ridings that they didn’t do as well in, but it might also lead to fewer voters province-wide feeling disenfranchised due to being represented by a second or third-place finisher. It would likely also mean a higher proportion of rural ridings would transfer due to smaller numbers of voters in each (though the ones where the BC Liberals ran up the score would be quite immune, such as Peace River North and Peace River South to name two).
Again, I don’t think for a moment that British Columbians would accept this system over the long-term, but they might accept it as a one-off if we needed a quick-and-dirty PR system for a single election while we waited for Elections BC to complete boundaries commissions and other issues related to implementing a new PR system approved in a referendum. Especially if there was an expectation that the next election would be conducted as soon as the new system was ready, meaning it would probably be fewer than four years away.