Polling in the BC election is showing a remarkable increase in support for the provincial Green party. The party that won less than 9% of the vote in 2013 and 2009 is now polling at around 20% across the province and over 30% on Vancouver Island. The potential for the Greens to significantly increase their vote raises important questions about what effect a Green surge would have on the NDP. If the Greens draw large numbers of left wing voters to them, vote splitting between them and the NDP could allow the Liberal party to pick up significant numbers of seats. It is thus important to examine where the Green party is having success, and test the its potential impact on NDP electoral prospects. In this post, I look at what would have happened in 2013 had polling numbers been where they were April 18, 2017. If the NDP can establish a solid lead over the Liberals, they should be protected from a Green surge. In a close election, however, a strong Green party is likely to be a problem for the NDP.
To examine the impact of the Green surge I compared aggregate polling data from CBC’s Poll Tracker to the results for the 2013 election. I looked at the numbers the tracker has estimated for three regions (Metro Vancouver, Vancouver Island, and the North/Interior) and compared them to the results the party received in 2013. I then adjusted the riding scores to account for the difference between 2013 and current polling numbers. For example, if a party is polling 5 percentage points above where they were in 2013 in Vancouver, I would add 5 percentage points to the parties’ vote percentage from 2013 in Vancouver ridings. This is a very crude measure of party support in different ridings. Unfortunately, however, without riding level polling, it is impossible to account for how popular opinion is spread across ridings in a particular part of the province. I classified ridings as safe if the gap between the first and second place party was more than 5% and competitive if the gap was less than 5%. For the 2017 numbers (though not for 2013) I also count any riding that looks would switch parties as unsafe, even if it looks like the margin between first and second place is higher than 5 percentage points. I do this because of the uncertainty surrounding polling, I am more confident in the 2013 analysis that uses actual election results. It is finally important to note that there has been redistricting between the 2013 and 2017 elections. This means that predictions for individual ridings for 2013 will not necessarily be accurate for 2017. This analysis can provide a general sense of where the election is competitive, but the exact numbers presented should be taken with a grain of salt.
A look at the 2013 results shows that the Liberals had a large number of safe seats. Of the 49 seats the Liberals won in 2013, 40 were by more than 5 percentage points. In contrast, the NDP won by more than 5 percentage points in only 26 seats, and the two parties were within 5 points of each other in 16 seats. The Greens were largely a non-factor. They won one seat in Victoria by a fairly margin and were competitive with both the Liberals and NDP in another.
Adjusting to match 2017 polling numbers shows some remarkable changes. The Green party is somewhat more significant. It still has only one safe seat, but the 2017 numbers would have been made the Green party competitive with the NDP in 6 seats and competitive with both the Liberals and NDP in an additional one. The big change, however, is the number of seats in which the Liberals and NDP would have ended up competing against each other. There are 31 seats in which 2017 polling numbers would have put the Liberals and NDP within 5 percentage points of each other or in which the 2017 number would have changed the party that won. The NDP would have only needed to win 14 of these seats (in addition to holding on to their 29 safe seats) in order to win a majority government. In these 31 competitive seats, the NDP would lead the Liberals by an average of 42% to 38% and would have had the highest predicted vote share in 17. These number suggested that if the 2013 election had finished with the numbers the parties are polling at today, the surge in Green support would not have prevented the NDP from winning a majority.
An examination of how this would have broken down regionally demonstrates that the Green threat is generally limited to Vancouver Island. In the Capital Region (Victoria and the surrounding area), the NDP would have had no safe seats, and would have had to compete with the Green party to win each of the 4/5 seats it won in 2013. Off the Island though, the NDP has significant numbers of safe seats in the regions were the Greens are most likely to be competitive in Vancouver and Burnaby. The bigger gains to be made by the NDP are in areas where the Green party is weakest, Northern and Interior British Columbia, and the suburbs around Vancouver.
New Democrats should be concerned by the regional distribution of seats they would need to take from the Liberals in order to compensate for losses to the Greens. They would have to pick up competitive seats in regions such as the North Shore, Richmond/Delta, Langley/Abbotsford, and the Okanagan, where they have been historically weak. The party would also have to do well in Central British Columbia, a region where the Liberals have had an average lead of 8 percentage points over them in elections between 1991 and 2013. Even though aggregated numbers suggest that the NDP would have been able to survive a Green surge, doing so requires the party to have success in areas of the province where they have struggled in the past. As such, the rise of the Greens presents the party with a significant threat.
A Green surge would have a decisive impact on an election in two scenarios, both opf which are ver plausible. The first is a situation in which the NDP and Liberal seat shares end up being quite close. In this case, losses on Vancouver Island may keep the NDP from forming the government. The second, is a scenario in which the Liberals and NDP numbers end up converging, and even the small numbers of voters that the Greens might pull from the NDP in the Interior and suburbs of Vancouver could allow the Liberals to win those seats. In this vein, it is important to note polls have the NDP and Liberals within the margin or error of each other, and that a significant number of the competitive seats are in areas of the province that have been traditionally Liberal. In a close election, a Green surge may prevent an NDP victory, and this very well may be a close election. At the same time, if the NDP can win with a 4 or 5 percentage point lead over the Liberals, they should be able to protect themselves from losing as a result of vote splitting with the Greens.