[EM] Election categories
Stephane Rouillon
stephane.rouillon at sympatico.ca
Sat Jun 5 10:05:02 PDT 2004
Elections are a way to take a decision for several people.
when looking to categorize elections, I suggest to split the process into three
components:
choice type, decision type, ballot type.
The first element is the kind of election those people want to have.
The second element is the way those people want to chose.
The last element is the format of the input each voter will provide.
To categorize elections, I would first present all different kind of elections.
I can think of four (4):
- binary choice;
- ordered set choice;
- multiple choice (or single-winner problem);
- representation problem (or wultiple-winner problem).
First one seems very easy, despite the fact it often hides miscellanous choices,
like:
Should we colonize mars (yes/no)? Several person could want to specify a minimal
date or a maximum cost to the adventure...
So the "it depends" or "I don't know" responses should always be considered.
Other typical question are: Does god exist? Is there life elsewhere in the
universe? To buy or not to buy?
FPTP fits those kind of elections.
But life is rarely just black and white...
The second class of election is a typical budget type: what percentage of the
PIB should the nation put into its military departement (0-100%)?
Those problem do not really have candidate, they even have some time an infinity
of responses. But their order helps justify one election method:
median vote. For the mars question above, the question could be: when should we
colonize mars, never being a valid option...
The two last problems are the ones described by James Green-Armytage.
I would only emphasize that the single-winner problem does really have a
competition philosophy comparable to wrestling:
last one that stands wins. So vote splitting and cloning are the main issues.
But the representation problem can be viewed as a mapping problem. Thus, to my
sense, proportionality should be its main issue.
James has well categorized the well known methods to choose among the candidates
for both election types.
I would only suggest that for the ballot types, a general version can be used. I
called it (writting to Forest) a universal ballot.
It's rated version could englobe all perticular cases (including approval
cut-off). Only post-rounds decisions would be
harder to cover: like in a run-off method I would vote A as long A is running,
if eliminated I would vote B if C leads over D or
C if D leads over C.
Last remark: setting categories is more useful when every possibility can be
placed somewhere, based more on its components description
than just on enumeration names ... The single-membered/multiple-membered
approach seems more important to me than the counting method
for instance. SPPA is "C. Proportional methods" but does not fit any later
description. Just putting "4. SPPA" is not very helpful. Creating a new
choice "3. single-membered but not necessarily single-winner" tells more.
I hope it is interesting,
Steph
> Then I'd probably go to the ballot type. There's
> 1. a choose-one ballot (plurality and runoff),
> 3. a ranked ballot (IRV, Condorcet... permissibility of equal rankings
> should probably not be considered until later since many ranked methods
> have versions that do and do not allow them...),
> 4. a rated ballot (cardinal ratings, etc.),
> 4. a limited ratings ballot (approval, or any system where the possible
> number of "scores" for a candidate is less than the number of candidates)
> 5. a combined ballot (a method combining different kinds of ballots in a
> single election), and then maybe
> 6. a miscellaneous category
>
> Hmmm... I guess that you could call approval either a limited-ranking
> ballot (one with only two possible rankings), or a limited-rating ballot
> (one with only two possible ratings, 1 and 0). I don't really have a
> strong opinion as to calling it one or the other. I don't even know
> exactly what distinguishes a rated ballot from a ranked ballot... Is it
> the possibility that in a rated there may be several more available
> "places" or "scores" then there are candidates? (e.g. 5 candidates ranked
> on a 100 point scale.) Or the idea that the number of available places is
> independent of the number of candidates in general? If the latter, then I
> guess approval would be more of a limited ratings system.
>
> Anyway, that's what makes the most sense to me now. In my own voting
> survey I don't have it grouped quite like that, actually, but it's
> relatively close. Here is the current table of contents for that, which
> shows the taxonomy I used. Maybe I should update it a bit at some point?...
>
>
> I. Single winner voting methods
> A. Non-ranked ballot methods
> 1. Plurality
> 2. Two round runoff
> 3. Approval
> B. Ranked ballot methods
> 1. Borda
> 2. Instant runoff voting / the alternative vote
> 3. Condorcet methods
> a. Minimax
> b. Smith set + minimax
> c. Schwartz set
> d. Schwartz sequential dropping
> e. Beatpath
> f. Ranked Pairs
> g. Other Condorcet methods
> i. Raynaud
> ii. Dodgson
> iii. Kemeny
> iv. Condorcet completed by IRV
> h. A strategy problem
> C. Miscellaneous single winner methods
> 1. Candidate withdrawal option IRV
> 2. Lowest two elimination runoff
> 3. Coombs
> 4. Bucklin
> 5. Cardinal ratings
>
> II. Multiple winner voting methods
> A. Non-proportional methods
> 1. At large plurality / block voting
> 2. Other non-proportional systems
> B. Semi-proportional methods
> 1. Cumulative voting
> 2. Limited voting and single non-transferable vote
> C. Proportional methods
> 1. Party list
> a. Open and closed lists
> b. Allocation formulas
> i. Largest remainder
> aa. Hare quota
> bb. Droop quota
> cc. Newland-Britton quota
> ii. Highest average
> aa. Saint-Lagüe divisors
> bb. D’Hondt divisors
> c. Thresholds
> 2. Single transferable vote
> a. Surplus transfer rules
> i. Random
> ii. Fractional transfer
> iii. Meek
> 3. CPO-STV
> D. Combined systems
> 1. Parallel
> 2. Mixed member proportional representation
> III. Direct democracy systems
> A. Proxy systems
>
>
"Dr. Ernie Prabhakar" a écrit :
> On Jun 4, 2004, at 6:21 PM, Eric Gorr wrote:
> > Thought people here would be interested in this message...
> >
> > http://groups.yahoo.com/group/instantrunoff-freewheeling/message/779
> >
>
> Thanks, I'd missed that change. Perhaps people here could help on the
> taxonomy question:
>
> http://en.wikipedia.org/wiki/Talk:Voting_system#classification_scheme_-
> _take_2
> > For example, I can think of at least three orthogonal ways to
> > categorize systems:
> > â–ª What the result is (e.g., single-winner, multiple-winner,
> > proportional)
> > â–ª How balloting is done (e..g., single vote, cardinal rating,
> > ranking)
> > â–ª How it is counted (e.g., pairwise, runoff, etc.)
>
> What do you all think the best way -- or perhaps the most useful ways
> -- to categorize different voting systems?
>
> -- Ernie P.
> -----------
> Ernest N. Prabhakar, Ph.D. <DrErnie at RadicalCentrism.org>
> RadicalCentrism.org is an anti-partisan think tank near Sacramento,
> California, dedicated to developing and promoting the ideals of
> Reality, Character, Community and Humility as expressed in our Radical
> Centrist Manifesto: Ground Rules of Civil Society
> <http://RadicalCentrism.org/manifesto.html>
>
> ----
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