In my post on electoral reform and the preferential ballot, I remarked that changing the rules benefits some players more than others. This is true of any change, and I suspect it’s one reason why electoral reform has been so difficult: the sense that the rules are being tweaked for someone else’s benefit.

As the centrist party, the Liberals would probably benefit from ranked or preferential ballots (and modelling appears to bear that out), and, funnily enough, ranked or preferential ballots happen to be Prime Minister Trudeau’s preferred option. So it’s easy to complain that the Liberals are rigging the game in their own favour.

But it’s important to keep in mind that, despite the lofty rhetoric about a “fairer” electoral system in which “every vote counts,” proportional representation also benefits some players more than others. The question is, which players?

Political parties for one: that much is obvious. (Although, as I’ve pointed out, not necessarily the current political parties. There would be a realignment.) But which political parties?

To answer that question, I looked at the results of every Canadian federal election going back to 1980, and compared what the actual results were under first-past-the-post with what they would have been under pure PR.

Now before we continue, we have to be mindful of a couple of things. For one, no one is actually proposing pure PR: most electoral reformers propose mixed-member PR or a single transferable vote. But we tend to use pure PR as our example because it’s a hell of a lot easier. For another, the electorate would almost certainly vote differently under PR or any other major rule change. There are too many variables at play, especially for someone as stats-challenged as myself.

But with all that in mind, what might PR have done, historically? Here’s a graph that shows the difference — not by which party, but the place in which a party finishes (i.e., in 2015 it was the Liberals, but in 2011 it was the Conservatives).

Difference in results between FPTP and PR in Canadian federal elections, 1980-2015

Difference in results between FPTP and PR in Canadian federal elections, 1980-2015

On average, the government party would lose 39 seats under PR. The official opposition party would gain two or three seats on average — basically a wash. The prime beneficiaries are the parties in third, fourth or fifth place. How much do they benefit? Here the Bloc Québécois confuses things, because their vote is concentrated in one province: they actually benefit from first past the post, and lose seats under PR — an average of nine. For other parties in third, fourth or fifth place, the average gain is around 22 seats.

So, compared with first past the post, PR is basically a means of transferring seats to the smaller parties. Not for nothing does PR tend to be popular among the parties that often finish in third, fourth or fifth place. They’re advocating for their own self-interest.

But what about the fringe parties? Under a pure PR system, some of them might actually have elected an MP. The Greens might have elected at least one MP since 1984; they’d have elected 21 in 2008 instead of none. But we’d also have seen MPs from the Christian Heritage Party, Libertarian Party, Marijuana Party, National Party — and, in 1993, two MPs from the yogic-flying Natural Law Party.

You have to admit, it would have made Parliament more interesting.

But if Canada were to adopt a system whereby political parties needed a minimum percentage of the popular vote to get party list representation in the House of Commons (as is the case in Germany, where the threshold is five percent), all of these parties would be shut out. As might some current parties: at the national level, neither the Bloc nor the Greens got more than five percent of the vote, though the Bloc got 19 percent in Quebec and the Greens eight percent in B.C. Under a mixed system they’d certainly elect individual MPs, and under a regional party list system they’d do all right — but almost every system short of pure PR would keep out most other fringe parties.

Unless, of course, electoral reform changes the behaviour of the electorate. Which it almost certainly will: voters would have almost no reason to vote strategically, and would be able to vote for their first preference, no matter how fringe or nutty. Mainstream coalition parties would fragment to cater to those preferences.

And there’s every chance of Canadians taking the opportunity to prank the system. We’ve got a nihilist streak in this country, one that tried to change the name of the Northwest Territories to Bob. One that gave the Rhinoceros Party several second-place finishes in the 1980s (under pure PR, the Rhinos would have elected three MPs in 1980). One that gave 84,743 votes to the Natural Law Party in 1993 precisely because they were batshit bonkers.

Just imagine what we could do if a few pranksters spread out across the country could get somebody elected. The political class clutching their pearls will only encourage us. Try to stop it with a five-percent rule and we’ll take that as a challenge. You just watch us.

That might actually be the best argument in favour of proportional representation, now that I think of it.