[EM] Absolutely new here

Benjamin Grant benn at 4efix.com
Sun Jun 16 08:58:42 PDT 2013


Let me put forth (better, I hope) a more complete thought (which is probably
one of those Bucklin Variants, as it turns out.)

 

The ballot has every candidate on it.  In order to be considered valid, each
voter must rank each and every one of them.  So with five candidates, a
valid ballot might look like: 1st:B/2nd:D/3rd:A/4th:E/5th:C  No duplicates,
no skipping.

 

Then we create a threshold of just over 50% of the number of votes.  If 100
people vote, then 51 is the threshold.

 

We then look at only the 1st place votes.  If anyone hit the threshold, they
win if they are the only one.  If more than one candidate hit the threshold,
the one that surpasses the threshold by more wins.

 

If no one yet hits the threshold, add in all the 2nd place votes, and check
again. If still no one hits the threshold, add in the 3rd place votes, and
so on.

 

It was a thought experiment I was doing, I'm not at all sure, for example,
that it might not be better to permit duplicates or skipping.  I obviously
need to go deeper.

 

I think my next task is to put a pause in the pursuit of different voting
systems to focus on understanding better the various criteria (later no
harm, Condorcet, etc), in much more depth, ie, what they are each about,
what it means that a system fulfills of fails one, etc.

 

I will post more about that shortly - let me know if I am dragging this
group to far into "voting theory kindergarten", but I really want to "get"
all this.

 

Thanks.

 

-Benn Grant

eFix Computer Consulting

 <mailto:benn at 4efix.com> benn at 4efix.com

603.283.6601

 

From: Jameson Quinn [mailto:jameson.quinn at gmail.com] 
Sent: Sunday, June 16, 2013 11:20 AM
To: Kristofer Munsterhjelm
Cc: Benjamin Grant; election-methods at lists.electorama.com
Subject: Re: [EM] Absolutely new here

 

As one of the principal advocates for Bucklin systems on this list, I
thought I'd expand a bit on Kristofer's excellent response.

2013/6/16 Kristofer Munsterhjelm <km_elmet at lavabit.com
<mailto:km_elmet at lavabit.com> >

On 06/16/2013 05:26 AM, Benjamin Grant wrote:

[...IRV discussion...]


[...good response...]

2)I haven't seen a voting system like this - what are the issues with
it? Upsides and downsides?

A)Each voter ranks their choices on their ballots, first through last place.

B)If one candidate got a majority of 1^st place votes, they win. If not,


the second place votes are added. If still no majority he third place
votes are added, and so on, until one candidate has a majority.

Would the above system work?


That's Bucklin. http://en.wikipedia.org/wiki/Bucklin_voting . It's one of
the few ranked methods that have been used in political elections in the
United States, and it has a connection to median rating (which elects the
candidate with highest median rating or grade).

It would work, but the rating variant is better. In the context of ranking,
Bucklin fails Condorcet, for instance.

 

In case it wasn't clear, by "rating", Kristofer means a system with a fixed
number of levels of support/opposition (typically 3-7), where voters can any
number (including 0) of candidates at a given level. Ranking means that
voters must give a strict ordering of candidates, with no ties or skipped
ranks.


It also has some bullet-voting incentive. 

 

In this case, "It" refers to the ranked version only.

 

Say that you support candidate A. You're reasonably sure it will get quite a
number of second-place votes. Then even though you might prefer B to A, it's
strategically an advantage to rank A first, because then the method will
detect a majority for A sooner.

One of the points of the graded/rated variants is to encourage the voters to
think in absolute terms ("is this candidate good enough to deserve an A")
rather than relative terms ("is this candidate better than that candidate").
If they do, then the method becomes more robust.

 

Thanks.

 

One think Kristofer didn't mention is that your definition wasn't quite
complete. What happens if two candidates attain a majority at the same rank,
or (in rated versions or due to truncation) no candidate attains a majority
without including the bottom support level? Resolving this issue requires a
Bucklin completion method, just as resolving cyclical preferences in
Condorcet requires a Condorcet completion method. Colloquially, Bucklin
completion methods are often called "Bucklin tiebreakers".

 

Thus, there are many possible Bucklin systems, including "ER-Bucklin" (which
majority is highest?), "Majority Judgment" (remove an equal number of
ballots at the pivotal/median rating for each candidate until one of them
gets a majority at a higher or lower rating), "Graduated Majority Judgment"
(find the candidate who needs the lowest percentage of their ballots at the
pivotal/median rating to attain a majority; also expressable as a simple
algebraic formula that gives a non-integer score to each candidate), and the
as-yet-unnamed method currently being discussed (for instance) here
<http://lists.electorama.com/pipermail/election-methods-electorama.com/2013-
June/031877.html>  and here
<http://lists.electorama.com/pipermail/election-methods-electorama.com/2013-
June/031880.html>  (find the candidate with the greatest number of
above-median votes). I'd appreciate it if you read the posts linked above
and responded with your own opinion as to naming.

 

Supporters of Bucklin methods (like me) typically speak of the following
advantages:

*	Voters can express, and the system can respond to, varying levels of
support. Score voting (aka Range voting) is even better in this regard, but
Bucklin systems are still better than most others.
*	In many cases, an "honest" (scaled utility) vote is strategically
optimal. For instance, say the rating categories were the letter grades A-F,
and the two frontrunner candidates both had a median of "C". A voter who had
given one of those two a "B" and the other one a "D" would have cast a
full-power vote, and would not need to regret not having given those
candidates an "A" and an "F". This contrasts with Score Voting, where in
general only approval-style votes (all top- and bottom-rating) are
strategically optimal. The hope is that by leaving more room for honest
voting, Bucklin systems will get better information from voters, allowing a
better result.

Welcome to the list, and we hope to hear more from you,

Jameson

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