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 54.2% of seats when we would expect 50.5%).

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–both occurrences–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 one place, 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.

The Brexit cycle

EDIT: the pollster has corrected an error. May’s deal is a Condorcet winner after all (i.e., it would beat either of the other options in one-on-one competition.) The Delta Poll blog post about the poll has been corrected, without any indication of the previous error, although its author did note the error on Twitter. The first pie diagram in the image has the numbers reversed.

_______original post below

Sometimes it just really is awesome to be a political scientist. You see, we have a large literature on the theoretical problem of preference cycles. But they don’t ever happen in real life, right?

Or we could depict it the following way, which makes clearer why it is called a “cycle”:

Smoke and chill

We have been dealing with heavy smoke from the Camp Fire in Butte County, which is a couple hours’ drive north of us. The weather conditions have been such that the smoke has settled and some days it has been like a fog that starts out moderately thick and never totally clears.

What I did not expect was that it would be so cold during this smoky phase. The fire began on 8 November, and the winds that initially made the fire so devastating died down late in the day on the 11th. Since then, we have had six straight mornings with low temperatures at 36F or lower, including three at 32 and two more at 33. This is substantially colder than the norm for this time of year. Usually–at least in the years I have been at this location–we do not get a morning below 32 until some time in December.

The NWS forecast discussion last night mentioned, “The smoke is keeping temperatures below normal blocking heating from the sun during the day and allowing heat to escape at night, unlike cloud cover.”

It is obvious that smoke cover would keep daytime highs down. In fact, we have not had a high temperature higher than 66 for the past six days, and some days have been only 62 or 63. That is near or a little below the norm for mid-November. (Normal low and high temperatures for the month of November around here would be more like 41 and 66.)

I would not have expected smoke to help keep it so cool overnight. Perhaps naively, I would have expected it to act more like cloud cover. Evidently, however, the fire has had the effect of getting our winter-chilling off to an early start. The deciduous trees are presumably dormant enough by now to “receive” chill, so this early cold snap is a good start.

The fire has been one of the worst disasters in the state in some time, and the air quality has resulted in UC Davis being shut down since 12 November and through the upcoming Thanksgiving holiday. Through all the awfulness, these cold mornings have been welcome.


What do folks think of this idea, proposed by Mark Roth in the thread on open-list MMP?

I do not believe it is entirely necessary to have two votes; though I don’t oppose the idea. Essentially I would have IRV-MMP. An instant runoff determines which candidate wins the local seat in each district. First preferences determine who receives the at-large seats. If a voter wants the Greens, but knows that they won’t win locally, a vote 1 Greens 2 Labor has the effect of supporting a winnable local candidate and helping the Greens secure seats in general. I would allow transfers to second (or lower) ranked parties should the first choice(s) of parties not reach a threshold. I would also be inclined to allow a List Party that isn’t running a candidate to appear on the ballot anyway; probably marked to indicate that the List cannot win the local seat. The candidates who lose in their local race would be selected to fill the at-large seats based on their personal vote counts. List order would only be a tiebreaker.

Decoy lists would technically be possible, but they would stick out like a sore thumb, require voter coordination to ensure that the “right” candidate gets the vote in the district level races, and would still need to front candidates in local races to have enough warm bodies.

As I say at the other thread in a comment of my own, I like it much better than the “AV+” idea of having two votes (one ranked-choice for local candidates and the other for list).

Is rural-urban PR gaining on MMP?

In the British Columbia mail-in referendum, the most likely option to win, should change from FPTP be endorsed, has seemed to be Mixed-Member Proportional (MMP). However, a poll from Mainstream BC, released on Nov. 8, suggests that one of the other options could be gaining.

The one that looks close, at least in this poll, is Rural-Urban PR (RUP). I reviewed all of the proposals before, and so will only briefly describe the RUP system here: It would be Single Transferable Vote (STV) for most of the province, but MMP in rural areas. The proposal is meant to address concerns that rural districts (ridings) would have to be too large if STV were used in the entire province, while still giving the rural interior a reasonable degree of proportionality.

This poll shows that on the critical first question, whether to keep FPTP or move to PR, the BC Interior prefers the status quo, 53.3% to 46.7%. Metro Vancouver voters only narrowly favor PR (50.1%), while Vancouver Island favors PR by a slightly wider margin (52.7%). The regional samples are small, so should be treated with caution. Nonetheless, they are suggestive of skepticism of PR in rural areas, exactly what the RUP proposal is meant to address. Overall, it is way too close to call: 50.5% for keeping FPTP, 49.9% for PR.

It is on preference over PR systems that we see the most interesting divide. According to this poll, MMP leads by a wide margin in Metro Vancouver: 50.4% to 32.2% for RUP and 17.4% for the third option, Dual-Member PR (DMP). On Vancouver Island, it is similar, but tighter: 40.4%, 38.3%, 21.3% (this is just 86 respondents). In BC Interior, however, the poll gets RUP on 49.5%, then MMP 37%, and DMP just 13.5%.

Overall, this still puts MMP in front, given the greater population of Vancouver: 44.8%, 38.2%, 17.0%.

It could be that RUP is gaining, as earlier polls had it and DMP both far behind MMP. There is an on-line presence for a specifically pro-RUP effort (“YUP for RUP”). There is some expressed support for RUP, for instance by Andrew Coyne in the National Post. He says he favors it “mostly for the STV part.”

It would be very interesting if RUP ended up winning, but on the strength of rural voters who, were it chosen, would vote by MMP, while Vancouver voters (who would vote by STV) had majority-preferred MMP but would get STV. OK, that was convoluted, but that is the point. It is not a likely outcome, but it is at least possible, provided it is really close in Vancouver and there is a decisive turn towards RUP in rural areas. And would be interesting!

The choice of PR model, if PR defeats FPTP in the first question, will be determined by province-wide alternative vote (the second question is a ranked ballot). So, it would be good to know what DMP supporters’ second choice tends to be. I would guess MMP, but that is just that–a guess. It probably depends on which feature of DMP that minority likes best–all members elected in local districts (for which STV would seem to beat MMP) or province-wide proportionality (for which MMP is clearly better than RUP).

A final note from the poll: It has 963 total respondents, but only 440 for the second question. So lots of voters may be planning to skip the question on choice of models. It is unclear whether that is because those who want FPTP are not weighing in at all, or because of pro-PR canvassers saying things like “if you are confused about the second part, you can skip it” (which I heard in my brief observation of campaigning).

Correction on BC’s MMP proposal

I realized only today that I had misread the proposal for the Mixed-Member Proportional (MMP) system in the British Columbia Attorney General’s report on the options. [Or maybe not, after all: See Wilf’s comment.]

I had thought the compensation would play out only in regions, as is the case in Scotland. I based this on the phrase in the report that says, “the List PR seats are allocated on a regional basis rather than a province-wide basis.” However, somehow I missed the clear statement in the preceding paragraph of the report, where it says, “The overall share of seats each party holds in the Legislative Assembly is determined by the party’s share of the province-wide vote it receives.”

In other words, the regions would affect only which specific candidates are seated from the compensatory (“top-up”) lists, and thus the regional balance of each party’s caucus. They would not affect the number of such seats a party wins overall.

The provision also makes workable the possible open list, which is given as an option to be worked out post-referendum, but which the Premier has said he will ensure is chosen rather than a closed list. If the lists were province-wide, open lists would make for more cumbersome ballots and arguably excess choice (as well as failing to ensure regional balance in the assembly).

The details of how one balances province-wide proportionality with open regional lists are complex. It is the system in Bavaria, however, so it is not unproven.

I have corrected my two previous entries on this accordingly:

1. BC electoral reform options for referendum

2. What can we expect from electoral reform in BC?


California statewide election vote totals

All of the offices elected statewide in California now have only two candidates in the November election, due to the “top two” runoff system. However, because the first round is no longer a primary in which various parties can pick nominees for the November ballot, the contests can feature two candidates of the same party or one or more independents instead of candidates of one or the other major party. (This is also true of district contests like US House and state legislative seats.)

Thus I thought I would exploit these features–constant number of candidates, but variable affiliations–to probe how a party’s failure to place a candidate in the top two affects voting. I am not claiming any causality or doing any subtle analysis here. Just blunt comparisons of statewide totals, which are suggestive.

Two contests, including Lt. Governor and US Senator, featured two Democrats. One featured a Democrat and a non-party candidate. One contest features two non-party candidates, because the state constitution mandates that the Superintendent of Public Instruction (SPI) is a non-partisan post. (This is the one office that could be decided in the June first round; it is a straightforward majority-runoff system.)

The bottom data row averages the Democratic and Republican votes across the five races that were Democrat vs. Republican. The right-most data column indicates how the votes cast compare to the governor’s race: a ratio of the vote total in a given race over votes cast for governor. Not surprisingly, governor drew the highest total.

We can see that the average Democrat won just over 5.1 million votes and the average Republican 3.1 million, in contests that had one and only one candidate of each of these two parties. Moreover, all the contests that were D:R straight fights had roughly 98% of the votes of the governor’s race.

On the other hand, if there were two Democrats, the total was under 90% of the governor total (83% for the Lt.Gov and 88.5% for the US Senate). This obviously is partly because many Republican-leaning voters simply skipped the intra-party Democratic contest. (The SPI race, where I believe both candidates were actually Democrats, has a similar ratio.) Nonetheless, that is not the entire story, as the total for the two Democrats in both these races is a lot more than the average single Democrat, at the same time as the leading Democrat did considerably worse than the average single Democrat. In other words, at the same time as Democrats split their own votes across their two candidates, clearly the candidates also picked up some Republican votes. This would be really interesting to investigate on a more granular basis.

Finally, the Insurance Commissioner race is notable. The “no party” candidate in the race is actually a Republican. In fact, he served under that party affiliation in the office before. But candidates choose, before the June first round, what party “preference” to indicate on the ballot (from the approved list), or whether to indicate no party preference. In this contest, the Democrat got far below the average for his party. It could be that there are Democratic-leaning voters who remember Poizner and think he did a good job, although he left the office in 2011, so I have some doubts. Alternatively, it could be that not running under the party label is a good strategy for a Republican in this state. He did not win, but he did get 49.0% of the votes, running around half a million votes ahead of the Republican gubernatorial candidate and around 700k ahead of the average Republican on the statewide ballot. Maybe other candidates of the weaker party in the race will hide their party label in the future, given the current electoral system makes it possible to be one of the top two without a stated party preference.