[EM] Lock-in / robust two vote MMP

[Closed Limelike Curves]

>
> Can you refer me to the South Korea court decision on that? Is it
> specifically the mixed single vote that was the problem?
>
That's my understanding of the article here:
https://en.wikipedia.org/wiki/South_Korean_proportional_constituency
It seems to imply that the current system of MMP (*de facto* parallel
voting) exists because a court decision prohibits the mixed single vote.
That said, it seems to be a poor translation, and I don't know Korean.

On Tue, Dec 3, 2024 at 1:29 PM Closed Limelike Curves <
closed.limelike.curves at gmail.com> wrote:

> That could be extra helpful in South Korea, where the courts struck down
>> the old mixed single vote system.
>
> Oh god no what did I do
>
> On Sat, Nov 30, 2024 at 8:21 PM Closed Limelike Curves <
> closed.limelike.curves at gmail.com> wrote:
>
>> Thinking about this: paired with proportional approval voting, this could
>> be a very good way to create a "second tier" while keeping the overall
>> system simple and easy to understand. That could be extra helpful in South
>> Korea, where the courts struck down the old mixed single vote system.
>>
>> Rules: every voter has 1 vote, which is equally divided between the
>> winning candidates they approve of, plus the party they support. This way
>> the party receives the "wasted portion" of every voter's ballot, i.e.
>> 1/(n_approved_winners+1) votes.
>>
>> You should be able to get away with very few list seats, since the local
>> elections are already mostly proportional. I'm mulling over how this
>> compares to my current-preferred system (mixed single vote with
>> Pukelsheim's method), especially strategically.
>>
>> (Am I right in guessing you're "Rankedchoicevoter" on Wikipedia, BTW?)
>>
>> On Mon, Aug 5, 2024 at 3:12 AM Abel Stan <stanabelhu at gmail.com> wrote:
>>
>>> Hello everyone,
>>>
>>> I am quite new here, and so far I am unsure whether a mixed method is
>>> going to raise your interest, but I would be very happy if you'd give it a
>>> chance. I had the idea about 2-3 years ago and have procrastinated on
>>> trying to publish it as a paper in a journal, which I would now want to
>>> really do, unless I find out that it is not new at all. I would also be
>>> grateful for any advice on that too if anyone has experience. So far I have
>>> encountered the idea only in traces, never fully described even though it's
>>> very simple, it might be one of those simple ideas that you just don't
>>> think of and once you hear it it doesn't seem new or you might assume
>>> that's already how it (MMP) is.
>>>
>>> My preliminary names for it are: "lock-in" MMP or "robust (two vote)
>>> MMP". It's not perfect, it shares all the flaws of single vote MMP in case
>>> there are not enough leveling seats or no cap on constituency seats per
>>> party.
>>>
>>> The problem is this (just saw this article explain it too:
>>> http://rhysgoldstein.com/2018/02/03/bon-mmp-bad-mmp/):
>>> One vote MMP is much more robust to strategic nomination (decoy lists)
>>> than 2 vote MMP, and it doesn't have the ticket split strategy. But you
>>> sacrifice the very important choice of sincerely splitting your vote (you
>>> like your local candidate, but not their party and vice versa)
>>> There is another system which solves this problem: the mixed ballot
>>> transferable vote (MBTV), which uses vote linkage instead of seat linkage.
>>> Vote linkage is less known and had some not so good implementations that
>>> might give it a bad reputation. But theoretically, with (single vote) vote
>>> linkage, you can eliminate strategies almost completely (I'd refer to
>>> Daniel Boschler's work on this), unlike with single vote MMP (seat
>>> linkage). You just need the correct formula (I would like to write a paper
>>> on this too, but it's less impressive since it's very impractical). The
>>> problem with even the "perfect" vote linkage system is that you need a lot
>>> of additional list seats, possibly even more than 80% of seats would be
>>> list seats, and you need an assembly that changes size every election. But
>>> with the mixed ballot transferable vote, you at least can have two votes
>>> without major issues.
>>>
>>> Ideally, we want a two vote version of seat linkage (which is way more
>>> efficient) which doesn't suffer from the problems of two-vote MMP. So a one
>>> vote MMP, but with actually two votes! Here's the solution:
>>> You need a mixed ballot, like in the German elections, so the two votes
>>> have to be in the same ballot. You read the ballot preferentially (like in
>>> STV or MBTV), but like this: If someone casts a ballot for the plurality
>>> winner their ballot gets "locked-in" for that party list. You cannot split
>>> your ticket then, your vote is already counted to elect someone, you don't
>>> get to vote for another party and get them list seats (whether sincerely or
>>> not). But, if you didn't vote for the plurality winner, your vote doesn't
>>> get locked in, your ballot counts to your list vote. The total used for
>>> top-up is the sum of the locked-in votes and the non-locked-in votes. The
>>> closest thing I found to this is that in Germany, if you voted for an
>>> independent who got elected, your second vote didn't count - which is good,
>>> otherwise it would make sense for every party to run "independents" who
>>> don't count for their list with compensation. Also, some papers on mixed
>>> systems theorised there is something that uses both seat linkage and vote
>>> linkage, but not like this: They mean the MMP variants where the two votes
>>> are added together, a crude but partially effective solution I assume.
>>>
>>> There are a few things to figure out: How to measure proportionality?
>>> With one vote and two vote MMP it's clear, you can measure how well you
>>> compensated to the list results, with lock-in MMP there is an intermediate
>>> "fictional" list vote total used for top-up, so I think this is the real
>>> yardstick of proportionality. Compensating towards the pure party list
>>> result actually hides that some can have more voting power than others.
>>> Another thing is independents if the ratio of SMD to list seats is 50:50,
>>> then any plurality winner under 50% is already lucky to get their seat,
>>> those votes don't lock into a party list (they lock into "none"), since
>>> independents have none. So like in one-vote MMP, independents can actually
>>> be a flaw in the system. But if independents receive more than 50% of votes
>>> (assuming equal population and turnout across districts), maybe those
>>> surplus votes should be "freed" like in STV. Many other things can be
>>> considered, like using it with ranked or approval systems, but this is just
>>> the main idea.
>>>
>>> Thank you for reading and I appreciate any feedback, especially if you
>>> know that this is not actually a new idea or that it has a fatal flaw
>>> (other than what the default one vote MMP already has).
>>>
>>> Best,
>>> Abel
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
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>>> info
>>>
>>
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