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

[Vidar Wahlberg]

On Thu, Jul 04, 2013 at 07:18:18PM +0300, Juho Laatu wrote:
>> 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.
> 
> Yes, the end result is probably very similar. The fact that each leveling seat is tied to one county further reduces the difference (since there are no "countyless" seats).

About the Norwegian leveling seat algorithm:
The leveling seats goes to the party (with at least 4% of the national
votes) with the highest quotient. Once a party in a county has received
a leveling seat, that county may not receive any more leveling seats.
The quotient is calculated as following:
(party_county_votes / (party_county_seats * 2 + 1) / (county_votes / county_seats)
"county_seats" does not include the leveling seat.
Since each county receives 1 leveling seat the result would be fairly
close to just increasing the amount of seats in the county by one, but
smaller parties who haven't received any seats at all in the county (but
got at least 4% of the national votes) have a slight advantage with the
leveling seat algorithm as the algorithm use 1 instead of 1.4 as the
first divisor.

>> 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.
> 
> I tend to give highest priority to reaching exact proportionality between parties at national level. I also don't like any threshold like concepts since I believe most democracies are stable enough to allow also one or two representatives of some minor groupings in the parliament. That think that would do no harm in stable countries like Norway. It is more important to allow all interest groups to get their own reprsnetatives.

If a party received a leveling seat with only 300 votes, then it
probably was in Finnmark as that county has a low population, but large
area, giving them 5 seats.

As for the election threshold, I completely agree with Juho, also
minorities should be represented in the parliament. I've never really
understood the argument that an increase in parties represented in the
parliament will lead to chaos. How the election threshold work in
Norway, that's not really what's preventing other parties to be
represented (that we're using 1.4 as the first divisor in Sainte-Laguë
is what's making it difficult for smaller parties to get a foothold).

> I favour systems that are so simple that regular voters can easily understand how they work.

Even though I'm a fan of Ranked Pairs & Condorcet methods, I too share
this sentiment. Another argument could be that voters probably would be
wary of drastically changing the existing voting system.
In the Norwegian voting system, changing it by removing election
threshold, increase seats in each county by 1 and remove leveling seats,
and possibly reduce the first Sainte-Laguë divisor slightly, say 1.3,
while making it possible for voters to rank parties, could greatly
help prevent the fear of "wasting" ones vote. Using the counting method
mentioned earlier (exclude party with fewest votes, rerun Sainte-Laguë
until all remaining parties got at least 1 seat), it's arguably easier
to explain than the current one with the leveling seat algorithm.

It wouldn't help on the "I can't vote on my favourite party because they
[may] cooperate with a party which I don't like", but that's arguably
more of an issue with the parliament (or the people) than the voting
system, so that's a bit out of scope here.


-- 
Regards,
Vidar Wahlberg