In my column for the CBC today, I looked at what impact a preferential ballot might have had on the 2015 federal election. Take a look at the full article.
The calculation was based on second choice polling data at the end of the campaign, which had been broken down to the region. So, with that information I was able to estimate which party a Conservative voter in British Columbia, for instance, would mark as his second choice. With that data, I was able to re-run the 2015 federal election in every riding.
Of course, this assumes that all else is equal, including how the campaigns would have unfolded. It also assumes that the regional-level second choice preferences apply in each riding, which of course would not always be the case. So a few assumptions have had to be made. But I think the exercise is nevertheless indicative of what impact a preferential ballot might have had, and what impact it would have in the future if the parties do not change their electoral strategies.
Since I ran this exercise down to the riding level and had the numbers on hand, I decided I might as well share the data with readers here. In the tables below, I've shown the results after going through the exercise. Blank results for a party mean it was dropped at an earlier ballot and its support redistributed to other parties.