[EM] Preferential voting system where a candidate may win multiple seats

Kristofer Munsterhjelm km_elmet at lavabit.com
Thu Jul 4 03:55:49 PDT 2013


On 07/04/2013 08:55 AM, Juho Laatu wrote:

> In principle ability to vote for persons helps populist candidates.
> My best understanding is that in Finland, that uses open lists, well
> known candidates (from sports, TV etc.) probably have slightly better
> chances to win a seat when compared to countries using closed lists,
> but that difference is not big. Also closed lists can be populated
> with well known figures to get "populist votes" (in addition to
> nominating experienced politicians).
>
> Also campaining could in principle be more populist in open lists,
> but I don't see big difference here either. In FInland the level of
> populism differs more between parties than between the candidates of
> a single party.
>
> All in all, I believe the risk of excessive populism is not big in
> ranked methods either.

Both closed list and open (and ranked) methods have their failure modes. 
Closed list fails when the party leadership becomes unaccountable and 
insulates itself, and then the voter is forced to either vote "my way or 
the highway" - i.e. to accept the leadership's ranking or to not vote 
for the party. Person-based methods fail when it produces an incentive 
to be excessively populist.

In a way, that's a mirror of the general balancing act of democracy. If 
it is too "representative" as opposed to direct, then the powerholders 
might just run away with the power and mockingly say to the voters that 
they have no choice but to vote for one of the powerholders. If it's too 
direct, then it can amplify too much and oscillate around various 
policies if not degenerating entirely to populism.

I suspect that the solution to this particular problem lies not in 
getting the balance right, but somehow setting up the right feedback 
system so that public discussion and opinion convergence can move beyond 
populism. That said, I think I favor ranked multiwinner methods if I 
have to choose: the populist objection seems to be employed to 
exaggerate the negative results of giving the people more choice.

>> The leveling seat algorithm is... peculiar.
>
> You said that you don't like methods that lead towards a two/three
> party system. In other words the method should allow also small
> parties to survive. I note that typically small districts are one key
> reason why small parties do not get any seats. If you e.g. have a
> district with 3 seats, it is obvious that only two/three largest
> parties can win there. The leveling seats (that are allocated based
> on support at national level) could fix that problem, but I
> understood that n Norway they don't apply to the smallest parties.
> Therefore the 5% threshold probably effectively reduces the chances
> of the smallest parties to get their proportional share (at national
> level) of the seats. It does not make sense to the voters to vote for
> parties that most likely will not get any seats in their district
> anyway.
>
> I don't know what the situation in Norway actually is today. My
> comments here are thus just general comments on how multi-winner
> election methods usually work.

The Norwegian threshold is at 4%. If parties get sufficient local 
support, they still get seats; the 4% only regards leveling seats.

As a concrete example, in the 2009 parliamentary election, the Liberal 
Party ("Venstre") achieved a support result of 3.9%, just below the 
threshold of 4%. In the previous election, their support reached 5.9%. 
As a consequence of going below the threshold, the party lost 8 of its 
10 MPs.

>> I'd like to get rid of both leveling seats and election threshold.
>
> If you want to achieve exact proportionality (also for small parties)
> I think it is important that proportionality will be counted at
> national level. Also in ranked methods it is not enough if each
> district does its best alone since the small number of seats per
> district will distort proportionality at national level. From this
> point of view the leveing seats (or any construction that aims at
> providing proportionality at national level) is good, and thresholds
> are bad.
>
> - - -
>
> I note that you can achieve national level proportionality in list
> based methods also without leveling seats. In Finland there was a
> proposal that was alrady once accepted by the parliament but then
> cancelled by the current government. This proposal counted the
> proportionality first at national level, and then allocated a
> predetermined number of seats to each district so that at the same
> time also the calculated national proportionality numbers were met.
> This means that the last seats in some districts were slightly
> "forced" to correct parties, to meeth the national proportionality
> target. All methods that try to reach multiple targets, like
> political proportionality and geographic proportionality at the same
> time will have some "rounding errors". In the Finnish proposal those
> rounding errors were thus solved by slight distortion in who and
> which party wins the last seat in each district, instead of using
> e.g. leveling seats to capture the rounding errors.

That doesn't sound so different from leveling seats. In the Norwegian 
system, you give each county an extra seat, but this seat is assigned 
based on the difference betweeen the seats so far allocated (on county 
by county basis) and the national apportionment. I'm not sure how the 
algorithm decides which county gets which party's seats, but it's not a 
simple biproportional thing.

I know that it has led to very counterintuitive results (e.g. a party 
getting a seat with only 300 votes). Thus, I would favor actual 
biproportional representation, because it tends to take seats away from 
a party where that party has weak support, and give seats where the 
party has strong support, thus significantly reducing the chance of 
getting counterintuitive results. The biproportional representation 
algorithm could even be limited so it can't change more than n seats, 
where n is the number of counties, thus retaining the balance between 
national and local representation. It might be a bit unintuitive, 
though, that the seats are floating: e.g. a county might get more than 
one "leveling" seat because that reduces the majority that has to be 
overruled.

> You had interest in guaranteeing that the "lost" votes of small
> parties will go to parties that are similar-minded. If one counts
> exact proportionality at national level the number of lost votes will
> be quite small. That alone might be enough for some needs. The
> traditional way of voting for one party or one candidate only could
> thus be enough, and there would not be need to have ranked votes for
> this reason. (Ranked votes could be there for other reasons, like to
> support party internal proportionality.)
>
> Ranked methods may also be quite heavy for the voter if there anre
> tens of candidates to rank.

I don't think there would be a need to rank tens of candidates or 
parties. Given enough seats, the list method is quite fair to the voters 
that vote for parties that get at least one seat. So unless there's a 
balancing system to pull in a more centrist direction for each county 
(electing C instead of L or R in a one-seat situation), then voters who 
vote for large parties wouldn't have to rank at all. The voters who vote 
for smaller parties would only have to rank up to a large party.

DAC/DSC variants may change this situation a bit, but I don't think it 
would be necessary to rank many parties in general.

 > For the needs of Finland I have been
> interested in methods that would combine lists and ranked votes in
> another way. The idea is that ranking would be used within one party
> only. This approach does not allow the ranked votes to be used to
> improve the proportionalty between parties (as in your original
> proposal). One reason why ranking would be party internal only is
> that in this way also bullet votes to one single candidate and votes
> that do not list all the (tens of) candidates of one single party
> would support the intended party with their full strength (the whole
> strength of each short vote will go to the intended party). It might
> be too tedious for the voters to first rank all the candidates of
> one's own party, then all the candidates of the next best party, then
> the third and so on. One could thus achive (almost exact) national
> proportionality by counting it at national level, and still keep
> voting simple, also when there are tens of hundreds of candidates (in
> each district). The actual paper ballots could be large lists of all
> candidates, or just simple paper ballots with maybe three slots/boxes
> for the numbers of three candidates (of one party).

That's like open list, but with ranking instead of just giving an extra 
vote to a single MP. Ideally, open list would let the voters who have a 
definite reason to prefer another ordering express that (and have that 
influence the final list), while letting everybody else default to the 
ordering set up by the party itself. However, the question of how to do 
the balancing there is difficult. On the one hand, voters that don't 
change the ranking may be expressing an explicit wish to have the 
ordering the party leadership provided. On the other, the voters may 
simply be saying "it doesn't matter to me". That's like the tension 
between average Range and sum-total Range.

If it's too tedious to rank the candidates of a party, I'd permit equal 
rank and truncation. Thus, anybody who wants to vote Approval-style can 
do so.

> If one wants to be more exact with national proportionality between
> parties (without forcing voters to rank also the candidates of other
> parties), one solution could be to allow the parties to determine
> their relationship to other parties. For example left wing parties
> could join together so that their extra votes would support other
> left wing parties and not the right wing ones. This gets however
> quite complex, and parties may not be interested in agreeing which
> parties are cosest to each others. Another approach would be to allow
> voters to rank also parties in addition to ranking candidates, but
> also that gets quite complex.

That solution doesn't seem to do very well where it's been tried. For 
instance, in Fiji, this led the parties to make deals among themselves 
to the detriment of the voters. Wikipedia mentions this:

'Vice President Ratu Joni Madraiwiwi expressed his own misgivings about 
the voting system on 3 November 2005. He said it made the work of 
political parties much easier and denied freedom of choice to voters, as 
a vote for a political party was ultimately a vote for any other party 
to which that party had decided to transfer its preferences. "In 
hindsight, it would perhaps have been preferable to leave the voter to 
make up his own mind," Madraiwiwi said.'

But unless there are very many parties, the party-sharing solution 
doesn't really do anything that ranked voting couldn't. The system is 
equivalent to having a ranked ballot where every voter votes according 
to the preference order of the party they voted first. Thus you'd still 
need some kind of ranked voting method to translate those rankings into 
an allocation, and that's the hard part.




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