In my last post, I looked at how the rise of the BC Greens might affect the NDP if they manage to hold on to their current levels of support. Polls in British Columbia are not always as reliable as one would hope, and with the main leadership debate still to come, there is plenty of time for the polls to change. In this post, I will look at what would have happened if a Green surge similar to the one happening now occurred in 2013. Where in my last post I looked at what would have happened had the parties had their current poll numbers, in this post I look at what would have happened had the Liberals and NDP won vote shares similar to their 2013 numbers. Together, these posts provide a sense of the possible outcomes of two different scenarios. This one provides a look at a case where the Liberals are ahead by a substantial margin and the last post a scenario where the NDP has a slight lead. A Green surge in the last election would have changed very little.
To look at the impact a rise in the Green vote I use April 18, 2017 polling data from CBC’s poll tracker to estimate party’s vote shares in each riding. Rather than estimating the support for the Liberals and NDP though, I take their 2013 results as is. I consider two scenarios when reducing Liberal and NDP support to account for Green growth. First, I consider a scenario where the Greens get 60% of their increase from the NDP and 40% of their increase from the Liberals. Second, I consider a scenario where the Greens get 80% of their increase in support from the NDP and 20% from the Liberals. This takes into account two different cases, one where the Greens draw only a slightly higher share of their increase from traditional NDP supporters and a second where the overwhelming majority of Green growth comes at the expense of the NDP. As in the previous post, it is important to note that these are crude estimates. They are designed to demonstrate the potential impact of a rise in Green support on the other parties, not to give a definitive account of which parties would have won which exact seats.
In the first scenario, the effect of the rise in Green support is small and largely confined to Vancouver Island. When only 60% of the growth in Green support comes at the expense of the NDP, only 5 seats change hands. Only one of those, in Burnaby/Coquitlam, is not on the Island. In this scenario, there are also 8 seats whose competitiveness changes. These seats either go from being safe seats (the winner no longer has a 5 percentage point lead over the second place finisher) to competitive ones, or from competitive to safe seats. All of these seats are on the Island (the riding in Burnaby Coquitlam was competitive both before and after the rise in Green support was estimated).
The impact of the Greens is more significant in the scenario where they draw 80% of their increase in support from the NDP. Under these circumstances, 9 seats (or 11% of the BC legislature at the time) would change parties. Again, these changes are largely confined to Vancouver Island. Only two seats off the Island (both in Burnaby/Coquitlam) would have elected a different MLA. A substantial number of seats, 14, would see a change in competitiveness, though most of those would also be on Vancouver Island.
The likelihood that a Green surge would lead to the NDP losing a large number of seats to a Liberal party taking advantage of vote splitting is also limited. Of the 5 seats that the NDP would lose if the Green party got 60% of their increase from the NDP, 4 would be won by the Green party. The Liberals would take only the seat in Burnaby/Coquitlam. If the 80% of the Green rise would have come from the NDP, the Liberals would take an additional two seats. There would also be two tied races, one between the Greens and the NDP, and one between the Greens, Liberals, and NDP. In both scenarios, the Greens and not the Liberals are the main beneficiaries of a rise in Green support.
Had the Green surge that is happening now occurred in 2013, not much would have changed. Vancouver Island would have elected more Green MLAs, and would have been more competitive, but for the most part, the rest of the province would have elected the same candidates. This is not to say that a rise in Green support cannot work to the advantage of the Liberals, but the Liberals and NDP have to very close in support in order for that to happen. In 2013, the gap between the two major parties was large enough that a rise in Green support would have had a relatively small impact on the election result.