Why “voting system”?

In the earlier entry on the BC referendum, I quoted a passage from the ballot question. It uses the term, voting system.

Yes, “voting system” rather than “electoral system”. Why? What the voters are being asked to decide is clearly what we political scientists mean by electoral system. Is there something objectionable about that term to the general public?

I do not ever use the term, voting system. However, if I did, I would probably understand it to mean the ballot format and other aspects of the process of casting a vote. I would not understand it to include how seats are allocated. An electoral system, as I understand it, is a set of rules that govern voting, counting, and allocation. A whole electoral system is assembly size, district magnitude, tier structure (if not “simple” single-tier), and the specific seat-allocation rule (edit: and the ballot structure). The BC proposals cover all these aspects. It clearly is a referendum on the electoral system. Yet it is officially, “a referendum on what voting system we should use for provincial elections.”

I find it puzzling, although not troubling in any sort of way. (Now, if the term starts creeping into political science, I reserve the right to object.) On the other hand, proponents of change in Canada seem to prefer to call proportional representation “ProRep” rather than PR. I can kind of understand that (“PR” means public relations to civilians). Whenever I see “ProRep” I flinch just a little. But if calling it that helps sell it, I can get over it.

New Brunswick 2018

The Canadian province of New Brunswick held its provincial assembly election on 24 September. The result is an assembly with no majority of seats.

The incumbent Liberal government, which won a majority in 2014 but had fallen to minority in the interim, came in second place in seats but first in votes in the 2018 election. The main opposition, Progressive Conservatives (PC), won just one seat more, and are short of a majority.

The Liberals have 21 seats on 37.8% of the vote, the PCs 22 seats on 31.9%, while a previously underrepresented party, People’s Alliance (PANB) and the Green Party each won three seats. The PANB won 12.6% of the vote and the Greens 11.9%. The NDP won 5% of the votes, but no seats.

The district-level results are interesting. The People’s Alliance leader, Kris Austin, won a clear majority (54.6% in Fredricton-Grand Lake, with the runner up being a PC incumbent with only 27.7%; in 2014, Austin had lost to the PC candidate 28.8%-28.5%!). In another riding, Fredricton-York, the PANB candidate defeated another PC incumbent, 33.7%-30.9%. The third PANB winner was in Miramichi and won 57.0% to 35.0% over a Liberal. I counted six other seats in which a PANB candidate came in second, although only one of these was really close (Southwest Miramichi-Bay Du Vin, where a PC has 35.4% over the PANB on 35.0%). The three districts the PANB won and the one where they are very narrowly behind, are all contiguous. It is clearly a regional party; it ran in 30 of the 49 ridings.

As for the Green winners, leader David Coon, who was their first elected MLA (2014) retained his seat easily, 56.3%-20.1% over a Liberal. In Kent North their candidate won 45.9%-37.4% over a Liberal. In Memramcook-Tantramar, Megan “Landslide” Mitton won by 11 votes (38.3%-38.2%) over a Liberal.  It seems there are two districts in which a Green came in second, but neither was close; in both cases the Liberal winner had a majority. The Green wins are not contiguous districts; the leader represents a seat in Fredricton and the other two are geographically large coastal districts. (See results and map at CBC; these are, of course, not necessarily final at this point, and there is even one Liberal lead of just 10 votes over a PC.)

It is not clear what the government result will be. I’ve been listening to CBC on the post-election discussions, and it seems the Greens have rejected a possible coalition with the Liberals; given that the results revised above suggest the Liberals are the Greens’ main opponent at district level, this reluctance has some (FPTP-based) logic to it. The Conservatives have said they will vote down a Liberal throne speech (not surprisingly). The PCs have declared all of their members are unwilling to stand for Speaker, and the Liberals also do not want any of their own to take the post. Without a Speaker, no other business can be transacted. So, for now at least, we have a stand off. (Update: The Liberal leader and current Premier Brian Gallant has said his party will put forth a candidate for Speaker today.)

It is worth noting that New Brunswick has quite a record of unusual election outcomes, and electoral-reform proposals. Just click “N.B.” at the bottom of this post to see previous entries on this recent history. Of particular interest is the time the Liberals took power thanks to a plurality reversal and promptly called off the previous (Conservative) government’s planned referendum on adopting MMP. Maybe it is time to dust off those proposals. The voters of the province seem unwilling to play the old FPTP game the way “the law” says to play it.

What could we expect from electoral reform in BC?

This week is the beginning of the mail voting period for the referendum on whether to reform the electoral system for provincial assembly elections in British Columbia. The ballot asks two questions: (1) Do you want to keep the current FPTP system or “a proportional representation voting system”: (2) If BC adopts PR, which of three types of PR do you prefer?

The second question offers three choices, which voter may rank: Mixed-Member Proportional (MMP); Dual-Member Proportional (DMP); Rural-Urban Proportional (RUP).

I have reviewed before what these options entails, and will not repeat in detail here. Besides, the official BC Elections site explains them better than I could. What I want to try to get it here is how we might expect BC’s provincial party system to change, were any of these options adopted. To answer that question, I turn, of course, to the Seat Product Model, including the extended form for two-tier systems developed in Votes from Seats.

The punch line is that the various scenarios I ran on the options all suggest the effective number of parties in the legislative assembly would be, on average, somewhere in the 2.46 to 2.94 range, the effective number of vote-earning parties would tend to be in the 2.83 to 3.32 range, and the size of the largest party would be somewhere between 45% and 51% of the seats. Again, these are all on average. The ranges just provided do not mean elections would not produce a largest party smaller than 45% or larger than 51%. Actual elections will vary around whatever is the point prediction of the Seat Product Model for any given design that is adopted. And fine, yet important, details of whichever system is adopted (if FPTP is not retained) will remain to be fleshed out later.

The ranges I am giving are formula-predicted averages, given the inputs implied by the various scenarios. I explain more below how I arrived at these values. The key point is that all proposals on the ballot are quite moderate forms of PR, and thus the party system would not be expected to inflate dramatically. However, coalition governments, or minority governments with support from other parties, would become common; nonetheless, single-party majority governments would not likely disappear from the province’s future election outcomes. As we shall see, one of the proposals would make single-party governments reman as the default mean expectation.

Before going to the scenarios, it is important to see whether the real BC has been in “compliance” with the Seat Product Model (SPM). If it has tended to deviate from expectations under its actual FPTP system, we might expect it to continue to deviate under a new, proportional one.

Fortunately, deviations have been miniscule. For all elections since 1960, the actual effective number of vote-earning parties has averaged 1.117 times greater than predicted. That is really minor. More important is whether it captures the actual size of the largest party well. This, after all, is what determines whether a single-party majority government can form after any given election. For all elections since 1960, the average ratio of actual largest-party seat share to the SPM prediction is 1.068. So it is even closer. For an assembly the size of BC’s in recent years (mean 80.7 since 1991), the SPM predicts the largest party will have around 57.8% of seats. The mean in actual elections since 1991 has been 62.7%. That is a mean error on the order of 4 seats. So, the SPM captures something real about the current BC electoral system.

Going a little deeper, and looking only at the period starting in 1996, when something like the current party system became established (due to the emergence of the Liberals and the collapse of Social Credit), we find ratios of actual to predicted as follows: 1.07 for effective number of vote-earning parties; 1.07 for largest parliamentary party seat share; 0.905 for effective number of seat-winning parties. If we omit the highly unusual 2005 election, which had an effective number of parties in the assembly of only 1.05 and largest party with 96.2%, we get ratios of 0.98 for effective number of seat-winning party and 0.954 for largest party size. The 2017 election was the first one since some time before 1960 not to result in a majority party, and it is this balanced parliament that is responsible for the current electoral reform process.

As for the proposed new systems, all options call for the assembly to have between 87 seats (its current size) and 95 seats. So I used 91, the mean; such small changes will not matter much to the estimates.

The MMP proposal calls for 60% of seats to remain in single-seat districts (ridings) and the rest to be in the compensatory tier (which would be itself be regionally based; more on that later). So my scenarios involved a basic tier consisting of 55 seats and a resulting 36 seats for compensation. Those 36/91 seats mean a “tier ratio” of 0.395 (and I used the rounded 0.4). The formula for expected effective number of seat-winning parties (Ns) is:

Ns=2.5^t(MS)^0.167.

With t=.4, M=1 (in the basic tier) and S=91, this results in Ns=2.81. I will show the results for other outputs below.

For the DMP proposal, the calculations depend on how many districts we assume will continue to elect only one member of the legislative assembly (MLA). The proposal says “rural” districts will have just one, to avoid making them too large geographically, while all others will have two seats by combining existing adjacent districts (if the assembly size stays the same; as noted, the proposals all allow for a modest increase). In any case, the first seat in any district goes to the party with the plurality in the district, and the second is assigned based on province-wide proportionality. For my purposes, this is a two-tier PR system, in which the compensatory tier consists of a number of seats equivalent to the total number of districts that elect a second MLA to comprise this compensatory pool. Here is where the scenarios come in.

I did two scenarios, one with minimal districts classified as “rural” and one with more. The minimal scenario has 5 such districts–basically just the existing really large territorial ridings (see map). The other has 11 such districts, encompassing much more of the interior and north coast (including riding #72, which includes most of the northern part of Vancouver Island). I will demonstrate the effect with the minimal-rural scenario, because it turned out to the most substantial move to a more “permissive” (small-party-favoring) system of any that I looked at.

Of our 91 seats, we take out five for “rural” districts, leaving us with 86. These 86 seats are thus split into 43 “dual-member” districts. The same formula as above applies. (Votes from Seats develops it for two-tier PR, of which MMP is a subset.) The total number of basic-tier seats is 48 (the five rural seats plus the 43 DM seats). There are 43 compensation seats, which gives us a tier ratio, t=43/91=0.473. Ah ha! That is why this is the most permissive system of the group: more compensation seats! Anyway, the result is Ns=2.94.

If we do the 11-rural seat scenario, we are down to 80 seats in the DM portion of the system and thus 40+11 basic-tier seats. The tier ratio (40/91) drops to 0.44. The resulting prediction is Ns=2.61. This does not sound like much, and it really is not. But these results imply a difference for largest seat size between the first scenario (45%) and the second (49%) that makes a difference for how close the resulting system would be to making majority parties likely.

Finally, we have RUP. This one is a little complex to calculate because it is really two different systems for different parts of the province: MMP for “rural” areas and STV for the rest. I am going to go with my 11 seats from my second DMP scenario as my “rural” area. Moreover, I understand the spirit of this proposal to be one that avoids making the districts in rural areas larger than they currently are. Yet we need compensation seats for rural areas, and like the full MMP proposal, RUP says that that “No more than 40% of the total seats in an MMP region may be List PR seats”, so this region needs about 18 seats (the 11 districts, plus 7 list seats, allowing 11/18=0.61, thereby keeping the list seats just under 40%.) That leaves us with 91-18=73 seats for the STV districts. The proposal says these will have magnitudes in the 2-7 range. I will take the geometric mean and assume 3.7 seats per district, on average. This gives us a seat product for the STV area of 3.7*73=270.

In Votes from Seats, we show that at least for Ireland, STV has functioned just like any “simple” PR system, and thus the SPM works fine. We expect Ns=(MS)^.167=2.54. However, this is only part of the RUP system. We have to do the MMP part of the province separately. With just 11 basic-tier seats and a tier ratio of 0.39, this region is expected to have Ns=2.13. A weighted average (based on the STV region comprising 80.2% of all seats) yields Ns=2.46.

The key point from the above exercise is that RUP could result in single-party majority governments remaining the norm. Above I focused mainly on Ns expectations. However, all of the predictive formulas link together, such that if we know what we expect Ns to be, we can determine the likely seat-share of the largest party (s1) will be, as well as the effective number of vote-earning parties (Nv). While that means lots of assumptions built in, we already saw that the expectations work pretty well on the existing FPTP system.

Here are the results of the scenarios for all three output variables:

System Expected Ns Expected Nv Expected s1
MMP 2.81 3.19 0.46
DMP1 2.94 3.32 0.45
DMP2 2.61 3.01 0.49
RUP 2.46 2.87 0.51

“DMP1” refers to the minimal (5) seats considered “rural” and DMP2 to the one with 11 such seats. If we went with more such seats, a “DMP3” would have lower Ns and Nv and larger s1 than DMP2, and the same effect would be felt in RUP. I did a further scenario for RUP with the MMP region being 20 districts, and wound up with Ns=2.415, Nv=2.83, s1=.52; obviously these minor tweaks do not matter a lot, but it is clear which way the trend goes.And whether any given election is under or over s1=0.50 obviously makes a very large difference for how the province is governed for the following four years!

I would not really try to offer the above as a voter guide, because the differences across systems in the predicted outputs are not very large. However, if I wanted to maximize the chances that the leading party would need partners to govern the province, I’d probably be inclined to rank MMP first and RUP third. The latter proposal simply makes it harder to fit all the parameters together in a more than very marginally proportional system.

By the way, we might want to compare to the BC-STV proposal that was approved by 57% of voters in 2005 (but needed 60%, and came up for a second referendum in 2009, when no prevailed). That proposal could have been expected to yield averages of Ns=2.61, Nv=3.0, and s1=.49. By total coincidence, exactly the same as my DMP2 scenario.

A final note concerns the regional compensation in the MMP proposal vs. province-wide in DMP. In an on-line appendix to Votes from Seats, I explored whether regional compensation in the case of Scotland produces a less permissive system than if compensation were across all of Scotland. I concluded it made no difference to Ns or s1. (It did, however, result in lower proportionality.) Of course, if it made a difference, province-wide would have to be more favorable to small parties. Thus if this were a BC voter’s most important criterion, DMP might pull ahead of MMP. However, the benefit on this score of DMP is greater under a “low-rural” design. The benefit of DMP vanishes, relative to MMP, if the system adopted were to be one with a higher share of seats marked as rural. I certainly am unable to predict how the design details would play out, as this will be left up to Elections BC.

The bottom line is that all proposals are for very moderately proportional systems, with MMP likely the most permissive/proportional on offer.

Bavaria 2018

As most readers of this blog probably already know, the German state of Bavaria held its state assembly election on 14 October. The result was a huge rebuke to the long-governing Christian Social Union, which is the regional alliance partner of federal Chancellor Angle Merkel’s Christian Democratic Union.

The CSU normally wins a majority of seats on its own, but will be far short this time. (I read somewhere that this is only the third time the party has been below 50% of seats in the postwar period, but I did not confirm whether that is correct.)

The CSU has won 37.2% of the votes, a loss of over ten percentage points compared to the previous state election. The biggest gain was for the Greens, who will now be the second largest party in the state assembly, having won 17.5% of the votes. The Free Voters are next, with 11.6%. Then comes the SPD; their 9.7% is a loss of over half their vote percentage since last election. The FDP barely cleared the 5% threshold (5.1%), and the extreme-right AfD easily entered the assembly for the firs time, with 10.2%. The Left Party was below the threshold (3.2%).

So, what will the next government of Bavaria be? The CSU has, of course, ruled out working with the AfD. They would have a majority if they joined with the Greens, but that seems unlikely. The CSU+FDP would probably not be a majority (although given below-threshold votes, which total around 8.6%, maybe it will be when the seat allocations are complete). That leaves the Free Voters as the most likely option. They are a center-right party; at least I think that is a fair characterization. Actually, characterizing them as a “party” might be controversial. They claim to be a collection of independents, and they do not require their members of the assembly to vote as a bloc. That may have to change, soon.

Brazil’s open list is (a little bit of) a hybrid now

Brazil is a classic case of open-list proportional representation (OLPR): lists win seats in proportion to their collective votes in a district (state), but candidates within the list are ordered solely according to preference votes obtained as individuals. These rules can result in individual candidates elected with very small preference-vote totals.

For the most recent Brazilian election, a new provision has gone into force. There is now a threshold on preference votes that candidates must obtain to be elected. This means that, in a very technical sense, a hybrid element has been brought into the Brazilian system. However, the provision is not the usual hybrid seen in “preferential list” systems, whereby seats not filled on preference votes are filled instead according to a party’s (or coalition’s) pre-determined rank. That hybrid format is what is typically called a flexible list or a semi-open list. However, Brazilian lists remain unranked, except via the preference votes.

Rather, in Brazil, a list that has an insufficient number of candidates with above-threshold preference votes forfeits those seats to other lists in the district. The threshold is set at 10% of the electoral quota, which is a Hare quota (1/M, where M is district magnitude).

This provision changed the allocation of 8 seats. Given a Chamber of Deputies with over 500 seats, we should not exaggerate the significance of the change, although of course, some other parties might have adjusted either their nomination behavior or their “intra-party vote management” practices (defined below) to avoid being hit by the threshold.

The Chamber’s website has an article regarding the seat shifts, and a table with the details (in Portuguese). The PSL, which is the party of the likely next president, Jairo Bolsonaro, won 7 fewer seats than it would have without the threshold. All these seats were in São Paulo, which is the highest-magnitude district in Brazil (M=70). The threshold there is thus 0.143% of the votes cast in the state. The Novo list in Rio Grande do Sul (M=31) also lost 1 seat due to the intra-list threshold. (Novo, meaning “New”, is a small liberal party.)

In São Paulo, the seven PSL candidates who were not eligible to take seats the list otherwise would have won had vote totals ranging from 19,731 to 25,908. They were replaced by candidates on six different lists with preference votes ranging from 56,033 to 92,257, suggesting the replacements had, on average, about three times the votes of the forfeiting candidates. (The party that picked up two of these seats was the Democrats.) In Rio Grande do Sul, the seat Novo forfeited would have been won by a candidate with 11,003 votes, but was instead filled by a candidate the Brazilian Labor Party (PTB, not to be confused with the PT of Lula) who had 69,904 votes, a preference-vote total 6.35 times greater than that of the forfeiting candidate.

As is clear from the vote totals of those who lost under this provision and those who gained, if the intention was to prevent candidates with marginal personal followings from riding in on the “coattails” of strong list-pullers (whose popularity increases the votes of the collective list), then the reformers can declare “mission accomplished”.

I am personally quite excited by this provision, which I had missed when summarizing minor changes made to the electoral law in 2017, because I once wrote up a proposal for just such a hybrid. It is in some text that was going to be part of one of the chapters in Votes from Seats, but Rein Taagepera and I decided it was not directly germane to the book and left it out. The chapter it would have been part of compares OLPR to the single non-transferable vote (SNTV) with respect to vote shares of first and last winners, and regarding the extent to which parties do (or do not) manage their intra-party competition.

Managing intra-party competition refers to parties doing one or both of: (1) restricting the number of candidates nominated, or (2) intervening in the campaign in an effort to shift votes from non-viable candidates to viable ones.

Under SNTV, these intra-party competition-management practices are critical because the total number of seats a party (or set of cooperating parties) can elect is entirely dependent on how many individual candidates it has whose votes are in the top-M vote totals in the district. Under OLPR, parties have no incentive to do this, if their goal is simply to maximize list seats–a list under OLPR can never displace seats to another list due to having “too many” candidates or having the candidates’ vote totals be widely unequal. (Parties may have other reasons to care about which candidates win, and multiple parties running in alliance face an SNTV-like conundrum in that they are competing with one another inside the list to get their candidates into the top s, where s is the number of seats won by the list. But these are separate problems, and the latter is a problem covered in Votes from Seats).

The proposal I drafted was a hybrid of OLPR and SNTV (unlike flexible lists, which re a hybrid of OLPR and closed-list PR). A threshold would be set on preference votes, and if a list won more seats, via application of the inter-list allocation rule, than it had candidates over the threshold, it would forfeit these seats. Any such forfeited seats would go into an “SNTV pool” to be be won by the otherwise unelected candidates with the highest preference-vote totals, independent of which list they had run on. My intention in devising this proposal was to encourage parties to be more active in managing their intra-party competition–taking some aspects of SNTV as beneficial–in order to make victory by candidates with marginal personal popularity less likely. (I would have set the threshold a little higher than 10% of a Hare quota.)

The article on the Chamber website is not clear on the precise rule now used in Brazil for deciding on the replacement candidates. In any case, it certainly has a similar effect to my proposal. (From a comment by Manuel at the earlier thread, it seems the forfeited seats are assigned proportionally rather than SNTV-like.) I can’t claim credit, as there is no way any Brazilian official saw my unpublished proposal. But I am pleased that some such a provision has been adopted somewhere.

Thanks to Dr. Kristin Wylie (on Twitter) for calling my attention to this article.

Brazil, 2018

Brazil has voted today in presidential, congressional, and state elections (governors and assemblies). The far-right candidate, Jair Bolsonaro, has obtained 46.8% of the presidential vote. The runner-up, Fernando Haddad of the Worker’s Party (PT), is on 28.3%. Given that the leading candidate did not win a majority, there must be a runoff. However, as we know, it is very rare for a first-round candidate with over 45% of the votes to lose the second round, and less likely still when the opponent is so far back.

As results come in for Chamber of Deputies, Senate, and state contests, I hope readers will add detail in the comments.

And if anyone has serious basis for hope that Bolsonaro can be defeated in the runoff, please tell. Because the idea of his being President of Brazil is just too depressing to contemplate. Then again, it seems to be both the hemisphere and the era of too-depressing-to-contemplate presidents.