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.

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?

 

NYT endorses a larger House, with STV

Something I never thought I would see: The editorial board of one of the most important newspapers in the United States has published two separate editorials, one endorsing an increase in the size of the House of Representatives (suggesting 593 seats) and another endorsing the single transferable vote (STV) form of proportional representation for the House.

It is very exciting that the New York Times has printed these editorials promoting significant institutional reforms that would vastly improve the representativeness of the US House of Representatives.

The first is an idea originally proposed around 50 years ago by my graduate mentor and frequent coauthor, Rein Taagepera, based on his scientific research that resulted in the cube root law of assembly size. The NYT applies this rather oddly to both chambers, then subtracts 100 from the cube root result. But this is not something I will quibble with. Even an increase to 550 or 500 would be well worth doing, while going to almost 700 is likely too much, the cube root notwithstanding.

The second idea goes back to the 19th century (see Thomas Hare and Henry R. Droop) but is as fresh and valid an idea today as it was then. The NYT refers to it as “ranked choice voting in multimember districts” and I have no problem whatsoever with that branding. In fact, I think it is smart.

Both ideas could be adopted separately, but reinforce each other if done jointly.

They are not radical reforms, and they are not partisan reforms (even though we all know that one party will resist them tooth and nail and the other isn’t exactly going to jump on them any time soon). They are sensible reforms that would bring US democracy into the 21st century, or at least into the 20th.

And, yes, we need to reform the Senate and presidential elections, too. But those are other conversations…

Is the effective number of parties rising over time?

I was recently having a conversation with another political scientist who showed me a graph that suggests the effective number of vote-earning parties in established democracies has been increasing over time. I was skeptical that it was, relative to baseline. Of course, if we do not have a baseline, we do not really know what is causing any such possible increase. The baseline should be the Seat Product Model, which tells us what we should expect the effective number of parties to be, given the electoral system. When we do the baseline, the increase over time remains, but is not significant.

Here is a graph with no baseline. It is just the the effective number of vote-earning parties (NV) in Western Europe (most countries–see below for notes on coverage). The scatterplot marks elections by a three-letter abbreviation for each country. The x-axis is years since 1945, the earliest election year in the dataset. The graph’s y-axis is unlogged, but the plotted regression curve and 95% confidence intervals are based on a logged NV.

(The regression is a GLS with random effects by country. It would not be much different if OLS were used.)

There does seem to be an increase over time. The regression estimates NV averaging around 3.42 in 1945 and around 4.60 in 2011. The 95% confidence intervals on those estimates are 2.96 – 3.96 and 3.98 – 5.32, respectively. So, yes, the vote is getting more fragmented over time in Western Europe!

But hold on a moment. We should look at the fragmentation relative to baseline. As shown in Votes from Seats, the seat product (mean district magnitude times assembly size; in a two-tier system, also taking into account the size of the compensatory tier) explains around 60% of the variance in key party-system outcomes, including the effective number of parties. It would be useful to know if the Seat Product Model (SPM) is on its way to being unable to account for party-system fragmentation if current trends continue. It would be useful to know if recent fragmentation is part of that other 40% (i.e., the amount of variance in NV that the SPM can’t account for). That is, are we witnessing some inexorable fragmentation of party systems that is resulting from the breakdown of existing party alignments in the electorate, and which electoral systems have begun to lose their ability to constrain? Should Western European countries go so far as to reduce their proportionality, in order to contain fragmenting trends?

So the next data visualization asks the question from a different perspective. Is the ratio of observed fragmentation to the SPM prediction increasing over time? We can take any given election’s actual NV, divided by the SPM-predicted NV to arrive at a ratio, which is equal to 1.00 for any election in which the result exactly matches the predicted value. (In other words, if R2=100%, all elections would have a ratio of 1.00.)

Here it is, for NV, again with the estimates from a GLS regression and the 95% intervals. In the regression, the ratio is entered as its decimal log, but the graph uses the underlying values for ease of interpretation.

What we see is indeed an increase (note the slope of the dashed line). However, the reference line at 1.00 (the log of which is, of course, zero) is easily within the 95% confidence interval of the regression throughout the six and a half decades of the data series. The regression estimates a ratio of actual to SPM of 0.911 in 1945 and 1.054 in 2011. The 95% confidence intervals are 0.782 – 1.062 and 0.905 – 1.228, respectively.

In other words, the increase is not statistically significant. There may in fact be an increase, which is to say that something in that other 40% is driving, over time, the SPM to be less successful at predicting the fragmentation of the vote. However, it could just be “noise”; we really can’t say, statistically, because of 1.00 remaining well within the confidence interval.

If it continues on current pace, then 1.00 (or rather its log) will be outside the confidence interval on NV as soon as the year 2065. I will put it on my calendar to check how we are doing at that time.

Independent of the statistical significance, there could be something of interest going on. Note that the regression trend does not cross the 1.00 line till about 42 years into the time series (i.e., 1987). This suggests that, prior to that time, the average election in Western Europe saw the vote be less fragmented than it “should have been”, according to its electoral system. That could suggest that major party organizations were partially overriding the electoral-system effect (producing party systems on average around 90% as fragmented as expected) in the early post-war years. In more recent times, the weakening of party alignments could be making the electoral system expectation finally be realized, with some tendency to exceed in recent times. But we really can’t say, given that the main conclusion is the SPM is all right, and should be for a little while yet, even if the current trend continues (which, of course, it might not).

I also wanted to checked the parliamentary party systems, that is, the effective number of seat-winning parties (NS).

Here it is even more clear that the SPM is doing all right! It is only about now that the regression estimate has finally reached 1.00, but the rate of increase is more minor than with NV, and clearly of minimal significance.

The regression estimates a ratio of actual NS to SPM prediction of around 0.909 in 1945 and 0.991 in 2011. Confidence intervals are 0.773 – 1.068 and 0.843 – 1.164, respectively.

It is somewhat interesting that the trend in the ratio for NV is rising above 1.00 before the ratio for NS. Perhaps there’s an explanation of interest in there. The electoral system more directly constrains NS, after all, and voters perhaps are more willing to “waste” votes as party alignments decrease. But it could just be noise.

(If I do a graph like the first one, with NS with the baseline, there is an increase, but less significant than for NV.)

The conclusion is that there is indeed some truth to the notion that West European party systems are fragmenting. However, relative to the Seat Product Model, they are fragmenting at a slow and hardly significant pace. How can that be? Well, perhaps it is obvious, or perhaps it is not. But a country’s seat product tends to increase over time. Most countries included here have expanded their assemblies over time, and some have also increased district magnitudes and/or adopted upper (compensatory) tiers. So, the effective number of parties should increase to some degree over time, even if voters were just as moored to their party organizations and identities as they ever were!

_________

Appendix: some details.


On the last point above: Specifically, a GLS regression on expected NS says we should have seen on average NS=3.58 in 1945 but 3.67 in 2011. That is not much, but it means some increase is “baked in” even before we look at how actual voters behave. Some part of the increase is in the 60% rather than the 40%.


I dropped Belgium and Italy from the regressions, although they are included in the scatterplots for recent years. The reasons for dropping are that we could not obtain data for the share of seats allocated in upper (compensatory) tiers for the years when these countries used multi-tier PR systems; without that, we can’t calculate the extended version of the SPM (for 2-tier PR). In the later years in the Italy series, when we have such data, these are actually even more complex rules (involving a majoritarian component and alliance vote-pooling), and so the SPM really can’t predict them. In Belgium, the electoral system has been “simple” since 2003, but I think we can agree that there is no semblance of a national party system in that country.


France is also not included, partly due to the importance of the elected presidency (after 1965) and partly due to the two-round system for assembly (after 1958). We do show in Votes from Seats that the SPM works pretty well for France nonetheless. So I doubt its inclusion would have altered the results much. But I wanted to stick to the PR systems and FPTP, which the SPM is designed to handle.

Open lists in MMP: An option for BC and the experience in Bavaria

One of the options for electoral reform in British Columbia is mixed-member proportional (MMP) representation. The criteria for the potential system allow for a post-referendum decision (if MMP is approved by voters) on whether the party lists should be open or closed. The guide that was sent to all BC voters shows a mock-up of a ballot that looks like New Zealand’s, with closed lists. However, the provincial premier has stated that, if MMP is adopted, lists will be open.

When it comes to lists, it is my opinion that citizens will elect all of the members of the legislature. They will select names that are representative of their communities.

I remain uncertain about the value of open lists under MMP. Is it worth the extra ballot complexity? What additional gain does one get from having preference votes determine order of election for those winning compensatory seats? The MMP Review in New Zealand after the 2011 referendum (in which voters voted to keep MMP) looked at this question extensively. It came down firmly on the side of keeping lists closed.

Nonetheless, the statement by the premier suggests he believes the system is less likely to be chosen if voters expect the lists to be closed. And, given regional districts on the compensation tier, as explicitly called for in the system proposal, the lists would not be too long and thus the ballots not too complex.

It happens that there is one MMP system in existence in which the lists are open. Such a system has been used in Bavaria for quite some time. I actually proposed such a model in a post way back in 2005, quite early in the life of this blog. At the time I had no idea that what I had “invented” was, more or less, the existing Bavarian model.

Of course, Bavaria just had an election. In the thread on that election, Wilf Day offered some valuable insights into how the open lists worked. I am “promoting” selections from Wilf’s comments here. Indented text in the remainder of this post is by Wilf.

The Bavarian lists are fully “open,” and the ballot position has no bearing on the outcome, except to the extent the voters are guided by it, especially seen in voting for the number 1 candidate.

Of the 114 list seats, 31 were elected thanks to voters moving them up the list, while 83 would have been elected with closed lists.

Did the first on the list always get elected? Almost. In the region of Lower Bavaria, the liberal FDP elected only 1 MLA, and he had been second on their regional list.

Did the open lists hurt women? I did not check most results, but the SPD zippers their lists, and I noticed in Upper Palatinate the SPD elected 2 MLAs, list numbers 1 and 3 (two women). Conversely, in Middle Franconia the SPD elected 4 MLAs: 1, 2, 3, and 5 (three men).

Little known fact: a substantial number of voters in Bavaria, being used to voting in federal elections where their second vote is just for a party, blink at the Bavarian ballot, look for the usual space to vote beside the party name, it’s not there, so they put an X beside the party name anyway. A spoiled ballot? No, they count it as a vote for the party. Not a vote for the list as ranked, it does not count for the ranking or for any candidate, but it does count in the party count. Just like Brazil, where a vote for the party is not a vote for the list ranking, except Bavaria does not publicize the option of voting for the party.

Among the more interesting new Free Voter MLAs:

Anna Stolz, lawyer, Mayor of the City of Arnstein; she had been elected Mayor in 2014 as the joint candidate of the Greens, SPD, and Free Voters; the local Greens said they were very proud of her as Mayor. The Free Voter delegates meeting made her number 5 on the state list, but the voters moved her up to second place as one of the two Free Voter MLAs from Lower Franconia.

From Upper Bavaria, the capital region, list #12 was Hans Friedl, with his own platform: “a socially ecologically liberal voice, an immigration law based on the Canadian model, no privatization of the drinking water supply, a clear rejection of the privatization of motorways”). The voters moved him up to #8, making him the last of 8 Free Voters elected in that region.

Note: the comments are excerpted, and the order of ideas is a little different from where they appear in the thread. I thank WIlf for his comments, and for his permission to make them more prominent.

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 2001 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.

Edit: The following paragraph is based on my own misreading of the proposal, which contrary to what I say here, calls for province-wide proportionality if MMP is chosen. What it says about Scotland still applies, so I will leave it here.

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.