[EM] Three rounds

[Dave Ketchum]

On Tue, 11 Nov 2008 22:18:55 +0000 (GMT) Juho Laatu wrote:
> I just referred to the basic property of IRV that it makes final irreversible decisions (eliminates candidates) before even reading the later preferences in each ballot.

Agreed.
> 
> (Some really strong compromise candidates may be eliminated early. And on the other hand also candidates with not much first place support may be elected.)

True that well liked candidates can lose if short on first place votes.

Possible, though difficult, to win with only a few first place votes - they 
must have more than the least as each least gets discarded.

DWK
> 
> Juho
> 
> 
> --- On Tue, 11/11/08, Dave Ketchum <davek at clarityconnect.com> wrote:
> 
> 
>>From: Dave Ketchum <davek at clarityconnect.com>
>>Subject: Re: [EM] Three rounds
>>To: juho4880 at yahoo.co.uk
>>Cc: election-methods at lists.electorama.com
>>Date: Tuesday, 11 November, 2008, 6:43 PM
>>Not clear to me what you meant.
>>
>>While ballots are almost identical, such that Condorcet can
>>accept what 
>>voters have done by IRV rules, their processing is entirely
>>different.
>>
>>IRV is interested in first choices.  If it decides that A
>>is a loser it 
>>must go back to the ballots that ranked A top and
>>reclassify them by next 
>>rank of each.
>>
>>Condorcet is interested in which candidate is best liked. 
>>For this it 
>>needs an NxN array summing all the ballots.  If it is
>>convenient to count 
>>the ballots in multiple locations this is fine - create an
>>NxN array at 
>>each location and sum them together in one final location
>>for analysis.
>>
>>DWK
>>
>>On Tue, 11 Nov 2008 06:39:53 +0000 (GMT) Juho Laatu wrote:
>>
>>>Yes, IRV is a good example. Most Condorcet methods do
>>
>>the comparisons/evaluation just once (when all the
>>candidates are in the same situation).
>>
>>>Juho
>>>
>>>
>>>
>>>
>>>--- On Tue, 11/11/08, Dave Ketchum
>>
>><davek at clarityconnect.com> wrote:
>>
>>>
>>>>From: Dave Ketchum <davek at clarityconnect.com>
>>>>Subject: Re: [EM] Three rounds
>>>>To: juho4880 at yahoo.co.uk
>>>>Cc: election-methods at lists.electorama.com
>>>>Date: Tuesday, 11 November, 2008, 2:47 AM
>>>
>>>
>>>>If I understand you 'sequential
>>>
>>elimination' is IRV
>>
>>>>and not Condorcet.
>>>>
>>>>DWK
>>>>
>>>>On Tue, 11 Nov 2008 00:01:36 +0000 (GMT) Juho Laatu
>>>
>>wrote:
>>
>>>>>The sequential elimination processes tends to
>>>>
>>>>introduce additional problems. Most Condorcet
>>>
>>methods
>>
>>>>don't have this problem.
>>>>
>>>>
>>>>>Condorcet may have some other problems that the
>>>>
>>>>sequential elimination based approach may avoid,
>>>
>>but
>>
>>>>especially in large public elections with
>>>
>>independent voter
>>
>>>>decision making and without too accurate knowledge
>>>
>>about the
>>
>>>>behaviour of other voters the performance of
>>>
>>Condorcet
>>
>>>>methods is very good.
>>>>
>>>>
>>>>>(Just checking how one could eliminate some of
>>>>
>>the
>>
>>>>problems of sequential elimination (e.g. by using
>>>
>>approval
>>
>>>>and avoid losing the "eliminated"
>>>
>>candidates).)
>>
>>>>>Juho
>>>>>
>>>>>
>>>>>--- On Mon, 10/11/08, Dave Ketchum
>>>>
>>>><davek at clarityconnect.com> wrote:
>>>>
>>>>
>>>>>>From: Dave Ketchum
>>>>>
>><davek at clarityconnect.com>
>>
>>>>>>Subject: Re: [EM] Three rounds
>>>>>>To: juho4880 at yahoo.co.uk
>>>>>>Cc: election-methods at lists.electorama.com
>>>>>>Date: Monday, 10 November, 2008, 8:10 PM
>>>>>>How do your thoughts compare with Condorcet
>>>>>
>>as a
>>
>>>>competitor?
>>>>
>>>>
>>>>>>It:
>>>>>>   Normally is defined as not doing
>>>>>
>>runoffs.
>>
>>>>>>   Has no problem with voters offering
>>>>>
>>whatever
>>
>>>>quantity
>>>>
>>>>
>>>>>>of ranks they choose, including doing
>>>>>
>>bullet
>>
>>>>voting.
>>>>
>>>>
>>>>>>DWK
>>>>>>
>>>>>>On Mon, 10 Nov 2008 16:05:16 +0000 (GMT)
>>>>>
>>Juho Laatu
>>
>>>>wrote:
>>>>
>>>>
>>>>>>>FYI. Finland used to have three rounds
>>>>>>
>>in the
>>
>>>>>>presidential elections. Since 1994 a
>>>>>
>>typical direct
>>
>>>>two
>>>>
>>>>
>>>>>>round method has been used. Before that (in
>>>>>
>>most
>>
>>>>elections)
>>>>
>>>>
>>>>>>the voters first elected 300 (or 301)
>>>>>
>>electors who
>>
>>>>then
>>>>
>>>>
>>>>>>voted in three rounds (two candidates at
>>>>>
>>the last
>>
>>>>round).
>>>>
>>>>
>>>>>>>Reasons behind moving to the direct two
>>>>>>
>>round
>>
>>>>system
>>>>
>>>>
>>>>>>included assumed general popularity of a
>>>>>
>>direct
>>
>>>>election,
>>>>
>>>>
>>>>>>some problems with heavy trading and
>>>>>
>>planning of
>>
>>>>votes by
>>>>
>>>>
>>>>>>the electors, possibility of black horses
>>>>>
>>and other
>>
>>>>voting
>>>>
>>>>
>>>>>>patterns that are not based on the
>>>>>
>>citizens'
>>
>>>>votes.
>>>>
>>>>
>>>>>>Maybe three rounds / three election days in
>>>>>
>>a
>>
>>>>direct
>>>>
>>>>
>>>>>>election would have been too expensive and
>>>>>
>>too
>>
>>>>tiring.
>>>>
>>>>
>>>>>>>- - - - -
>>>>>>>
>>>>>>>One somewhat related method:
>>>>>>>
>>>>>>>I sometimes played with the idea that
>>>>>>
>>in IRV
>>
>>>>one would
>>>>
>>>>
>>>>>>not totally eliminate the least popular
>>>>>
>>(first
>>
>>>>place)
>>>>
>>>>
>>>>>>candidates but would use some softer means
>>>>>
>>and
>>
>>>>would allow
>>>>
>>>>
>>>>>>the "eliminated" candidates to
>>>>>
>>win later
>>
>>>>if they
>>>>
>>>>
>>>>>>turn out to be the favourites of many
>>>>>
>>voters (after
>>
>>>>their
>>>>
>>>>
>>>>>>first preference candidates have lost all
>>>>>
>>chances
>>
>>>>to win).
>>>>
>>>>
>>>>>>>One could e.g. force supporters of the
>>>>>>
>>>>>>"eliminated" candidates to
>>>>>
>>approve more
>>
>>>>than one
>>>>
>>>>
>>>>>>candidate (at least one of the
>>>>>
>>>>"remaining"
>>>>
>>>>
>>>>>>candidates) (instead of just bullet voting
>>>>>
>>their
>>
>>>>second
>>>>
>>>>
>>>>>>preference). On possible way to terminate
>>>>>
>>the
>>
>>>>algorithm
>>>>
>>>>
>>>>>>would be to stop when someone has reached
>>>>>
>>>50%
>>>
>>>>approval
>>>>
>>>>
>>>>>>level.
>>>>>>
>>>>>>
>>>>>>
>>>>>>>Also in "non-instant" runoffs
>>>>>>
>>one
>>
>>>>could e.g.
>>>>
>>>>
>>>>>>force the voters to approve at least one on
>>>>>
>>the
>>
>>>>>>"remaining" candidates. (One
>>>>>
>>could
>>
>>>>eliminate more
>>>>
>>>>
>>>>>>than one candidate at different rounds.)
>>>>>>
>>>>>>
>>>>>>
>>>>>>>Juho
-- 
  davek at clarityconnect.com    people.clarityconnect.com/webpages3/davek
  Dave Ketchum   108 Halstead Ave, Owego, NY  13827-1708   607-687-5026
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