Is AV just FPTP on steroids?

In debates over electoral systems in Canada, one often hears, from otherwise pro-reform people, that a shift to the alternative vote would be worse than the status quo. It is easy to understand why this view might be held. The alternative vote (AV), also known as instant runoff (IRV), keeps the single-seat districts of a system like Canada’s current first-past-the-post (FPTP) system, but replaces the plurality election rule in each district with a ranked-ballot and a counting procedure aimed at producing a majority winner. (Plurality winners are still possible if, unlike in Australia, ranking all candidates is not mandatory. The point is that pluralities of first or sole-preference votes are not sufficient.)

Of course, the claim that AV would be FPTP on steroids implies that, were Canada to switch to AV, the current tendency towards inflated majorities for a party favored by less than half the voters would be even more intensified. This is plausible, inasmuch as AV should favor a center-positioned party. A noteworthy feature of the Canadian party system is the dominance, most of the time, by a centrist party. This is unusual in comparison with most other FPTP systems, notably the UK (I highly recommend Richard Johnston’s fascinating book on the topic). The party in question, the Liberal Party, would pick up many second preferences, mainly from the leftist New Democratic Party (NDP) and so, according to the “steroids” thesis, it would thus win many more seats than it does now. It might even become a “permanent majority”, able to win a parliamentary majority even if it is second in (first-preference) votes to the Conservatives (who thus win the majority or at least plurality of seats under FPTP). The “steroids” claim further implies that the NDP would win many fewer seats, and thus Canada would end up with more of a two-party system rather than the multiparty system it has under FPTP.

There is a strong plausibility to this claim. We can look to the UK, where AV was considered in a referendum. Simulations at the time showed that the Liberal Democrats would stand to benefit rather nicely from a change to AV. While the LibDems are a third party, heavily punished by the FPTP electoral system even when they have had 20% or so of the votes, what they have in common with the Canadian Liberals is their centrist placement. Thus, perhaps we have an iron law of AV: the centrist party gains in seats, whether or not it is already one of the two largest parties. An important caveat applies here: with the LibDems having fallen in support since their coalition with the Conservatives (2010-15), the assumptions they would gain from AV probably no longer apply.

On the other hand, we have the case of the Australian House of Representatives, which is elected by AV. There, a two-party system is even stronger in national politics than in the FPTP case of the UK, and far more so than in Canada. (When I say “two party” I am counting the Coalition as a party because it mostly operates as such in parliament and its distinct component parties seldom compete against one another in districts.)

It is not as if Australia has never had a center-positioned party. The Australian Democrats, for example, reached as high as 11.3% of the first-preference votes in 1990, but managed exactly zero seats (in what was then a 148-seat chamber). Thus being centrist is insufficient to gain from AV.

Nonetheless, the combination of centrism and largeness does imply that Canada’s Liberals would be richly rewarded by a change to AV. Or at least it seems that Justin Trudeau thought so. His campaign promised 2015 would be the last election under FPTP. While he did not say what would replace it, he’s previously said he likes a “ranked ballot” and he pulled the plug on an electoral-reform process when it was veering dangerously towards proportional representation.

Still, there are reasons to be somewhat skeptical, at least of the generalization of the Australian two-party experience. The reasons for my caution against the “steroids” view are two-fold: (1) the overlooked role of assembly size; (2) the ability of parties and voters to adapt.

Assembly size is the most important predictor of the size of the largest party, disproportionality, and the effective number of seat-winning parties in countries that use single-seat districts. (It is likely relatively less important when there are two rounds of voting, as in France, but still likely the most important factor.) This is a key conclusion of Votes from Seats. It is thus important not to overlook the fact that Australia has an assembly size considerably smaller than Canada’s. In the book, Taagepera and I show that Australia’s effective number of seat-winning parties and size of largest parliamentary party are almost what we would expect from its assembly size, even if FPTP were used. (See also this earlier post and its comment thread; how close it is to expectation depends on how we count what a “party” is.) The data are calculated over the 1949-2011 period, and the effective number of parties has been just 1.10 times the expectation from the Seat Product Model (which is based only on assembly size when single-seat districts are used). Similarly, the average largest party has been 93% of the expected size (averaging 50.5%  of seats when we would expect 54.2%).

Thus we do not need to invoke the alleged steroids aspect of AV to understand the dominance of two parties in Australia. But this does not mean it would not make a difference in Canada. Consider that the current effective number of parties and size of the largest party in that country, averaged over a similar period, are also just about what we should expect. The multipartism, including periodic minority governments, that characterize Canada are not surprising, when you use the Seat Product Model (SPM). They are surprising only if you think district magnitude is all that matters, and that FPTP is FPTP. But it isn’t! An electoral system using the FPTP electoral rule with an assembly of more than 300 seats is a different, and more multiparty-favoring, electoral system than one with 150 seats. Replace “FPTP” in that sentence with “AV” and it is surely still true.

But what about the centrist party, the Canadian Liberals? Surely AV would work differently in this context, and the Liberals would be a much more advantaged party. Right? Maybe. If so, then it would mean that the SPM would be overridden, at least partially, in Canada, and the largest party would be bigger than expected, for the assembly size, while the effective number of parties would be lower than expected. Of course, that’s possible! The SPM is devised for “simple” systems. AV is not simple, as we define that term. Maybe the SPM is just “lucky” that the one country to have used AV for a long time has the expected party system; or it is lucky that country has the “correct” assembly size to sustain two-party dominance. (Australia is the Lucky Country, after all, so if the SPM is going to get lucky somewhere, it might as well be Australia.)

This is where that other factor comes in. While no one has a crystal ball, I am going to go with the next best thing. I am going to say that the SPM is reliable enough that we can predict that, were Canada to have AV, it would have an effective number of parties around 2.6 and a largest party with around 48% of seats. In other words, just about where it has been for quite some time (adjusting for the House size having been a bit smaller in the past than it is now). Note these are averages, over many elections. Any one election might deviate–in either direction. I won’t claim that a first election using AV would not be really good for the Liberals! I am doubting that would be a new equilibrium. (Similarly, back in 2016 I said my inclination would not be to predict the effective number of parties to go down under AV.)

Parties and voters have a way of adapting to rules. Yes the Liberals are centrist, and yes the Conservatives are mostly alone on the right of the spectrum (albeit not quite as much now, heading into 2019, as in recent years). But that need not be an immutable fact of Canadian politics. Under AV, the Liberals might move leftward to attract NDP second preferences, the NDP center-ward to attract Liberal and even Conservative second preferences, the Conservatives also towards the center. It would be a different game! The Greens and other parties might be more viable in some districts than is currently the case, but also potentially less viable in others where they might win a plurality, but struggle to get lower ranked preferences. The point is, it could be fluid, and there is no reason to believe scenarios that have the largest party increasing in size (and being almost always the Liberals), and correspondingly the effective number of parties falling. With 338 or so districts, likely there would remain room for several parties, and periodic minority governments (and alternations between leading parties), just as the SPM predicts for a country with that assembly size and single-seat districts.

As I have noted before, it is the UK that is the surprising case. Its largest party tends to be far too large for that huge assembly (currently 650 seats), and its effective number of seat-winning parties is “too low”. Maybe it needs AV to realize its full potential, given that the simulations there showed the third party benefitting (at least when it was larger than it’s been in the two most recent elections).

Bottom line: I do not buy the “FPTP on steroids” characterization of AV. I can understand were it comes from, given the presence in Canada of a large centrist party. I just do not believe Liberal dominance would become entrenched. The large assembly and the diversity of the country’s politics (including its federal structure) both work against that.

I agree with electoral reformers that PR would be better for Canada than AV. I also happen to think it would be better for the Liberals! But would AV be worse than FPTP? Likely, it would not be as different as the “steroids” claim implies.

Plurality, FPTP, SMP. What’s in a name?

For such a widely used and analyzed electoral system, the typical Anglo-American means of electing legislators sure has a wide range of names.

My general view is that First Past the Post (FPTP) is the worst of all possible names, aside from the others that have been used from time to time.

The main advantage of FPTP (as a name, not a system) is that it is widely understood and the apparently dominant name in numerous countries that actually use the system. It has various disadvantages, however, including being an awkward name to say in full, and an unpronounceable acronym (which I have heard even political scientists mess up as “FTPT”). It is also a little weird to have one of our major concepts be described by a term from horse racing. And, as both Nathan Batto in a recent post at his blog, and Rob Richie in a comment here in 2011 noted, in an election using this method, there is no fixed post, unlike at your local racetrack.*

I would actually prefer to banish proper names for electoral systems entirely, and describe them by their most important parameters. The preference for the rich detail of proper names suggests, as Rein Taagepera put it in Predicting Party Sizes (2007), a preference for zoology over the broad generalizations of molecular biology. Therefore, were I to be strictly adhering to my own principles, I would say the electoral system in question is M=1, single-round, simple quota. Or something like that. Not exactly a classification scheme I expect to catch on, but a vast improvement analytically over attempting to give a proper name to every combination of rules ever invented here or there. I have no idea how many times I have received a description of some bizarre melange of rules and been asked, what would you call this? I often respond by saying, well, let’s break it down into its parts and see where that gets us.** I really do prefer this over the naming game–in principle. It might be impossible to provide a few concise component-based terms for complex multi-tier systems; I am afraid proper names like MMP will continue to grace the pages of this blog and my academic writings. And if that is the case, I suppose we need a convenient proper name for the standard Anglo-American system.

Some sources, including works I like and assign in classes, use SMP, meaning single-member plurality. It is descriptive, and component based, referencing the district magnitude (“single member”) and the allocation formula (“plurality”). It has one very big flaw, however, and I recommend not using it. The letters within it are too widely used to refer to other systems or features of systems. I became aware of this while recently revising a chapter on New Zealand’s current electoral system, which is, of course, in its full proper-name glory, Mixed Member Proportional (MMP). The editors of the volume advised authors to use SMP for the system otherwise known as FPTP (or in New Zealand, FPP, because, why use a letter for the definite article?). However, I just can’t see writing about the change from SMP to MMP, without confusing the poor reader to an even greater depth than various political scientists, because it logically suggests that only one aspect of New Zealand’s system was changed, S to M.*** In fact, I have heard even electoral-systems specialists inadvertently refer to MMP as multi-member proportional (as though there were any other kind), because, after all, we have “SMD” (single-member district) and we have “MMD” (multi-member district), so “MMP” must mean multi-member…, right? I guess that means logically SMP could mean “single-member proportional”, which is actually an oxymoron, but would be a semi-accurate description of a system in which a substantial share of the seats are elected by M=1, yet the overall allocation assures a large measure of proportionality. In other words SMP=MMP! What a morass!

Because of the confusion by experts around a conference table back in 1998, I drafted a recommendation to drop the acronyms SMD and MMD altogether. This recommendation appears in an appendix to the book that came out of that conference, Mixed Member Electoral Systems: The Best of Both Worlds? (please never forget there is a question mark in the subtitle!). In the book, we argue instead for referencing districts as single-or multi-seat (SSD vs. MSD), and I have continued to do so, to make the acronyms look less like the proper name of the New Zealand system. Of course, really, I would prefer never to use acronyms to refer to district magnitude when we can easily say “one-seat districts” or “M=1 districts”, or a system with M>1, etc. But if we must use magnitude acronyms, can we please use SSD (MSD) rather than SMD (MMD)?

So then, what of the electoral system otherwise known as FP(T)P? Well, I suppose we could use SSP (single-seat plurality). I am not sure I like it, but it avoids the confusion of SMP and MMP. Duverger called it the “simple majority, single-ballot system”. I find “simple majority” confusing, and much prefer “plurality”, while “single-ballot” is arguably redundant. He was contrasting it to the two-round majority system, and presumably also to the possibility of two round majority-plurality.

I could live with just saying “plurality system”. I think it is mostly clear, though it does refer only to the allocation rule and leaves open how many legislators (members/seats) are being elected per district. I generally understand FPTP to refer to M=1 plurality, although I think I have used it myself to refer to M>1 list plurality (which maybe I should not?). Besides, is it just me, or is “plurality” really hard to say? And I might note that Fowler’s Modern English Usage says that “plurality” should mean “many” (as in “a plurality of different names for the same old electoral system”) and that the word for “the largest” should be “plurity”.

So there you have it: a semi-serious plea for calling it the plurity system, or M=1 plurity, or SSP (single-seat plurity). Anything but SMP. And I still think FPTP is the worst name except for all the others–if one must be an electoral zoologist.

*Rob said that “top of the heap” would be more accurate, to which Bob Richards, responded:

Top of the heap — TOTH — unlike FPTP it’s an acronym you can actually pronounce. It even has an appropriately icky sound (perhaps I’m biased). Best of all, it is scrupulously accurate.

** I am certainly not always consistent, having devoted a whole thread once to a “name this system” competition.

*** Which I would otherwise understand as meaning the Size of the legislature and the Magnitude of districts, respectively.