[EM] Why I think IRV isn't a serious alternative 2

Dave Ketchum davek at clarityconnect.com
Mon Dec 22 20:04:55 PST 2008

Seems the thoughts can be split.
      The examples under discussion were a very limited subset of what is 
possible:  A majority preferred M>R, and another majority preferred M>D 
(knowing this much, comparing R vs D does not matter).
      Other elections could have had more interesting rankings, and perhaps 
have required more complex thoughts as to majorities - such as you write of.

Stretched thought:  "In a crowded field, a weak CW may be a 
little-considered candidate that every voter ranks next to last."

Look at the ranking of such a CW - hard to get to be liked better than the 
opposition when the opposition often ranks higher:
      x>CW - counted for every voter for every candidate ranked above CW.
      x=CW - not counted (mostly for pairs where a voter did not rank either).
      CW>x - counted where a voter ranked x below CW, or did not rank x.


On Mon, 22 Dec 2008 20:56:03 -0500 Terry Bouricius wrote:
> Dave,
> I think you make a common semantic manipulation about the nature of a 
> Condorcet winner (particularly in a "weak" CW example) by using the term 
> "wins by a majority." In fact, each of the separate and distinct pairwise 
> "majorities" may consist largely of different voters, rather than any 
> solid majority. This is why I think the Mutual-Majority Criterion is a 
> more useful criterion. In a crowded field, a weak CW may be a 
> little-considered candidate that every voter ranks next to last.  The 
> phrase "wins by a majority" creates the image in the reader's mind of a 
> happy satisfied group of voters (that is more than half of the electors), 
> who would feel gratified by this election outcome. In fact, in a weak CW 
> situation, every single voter could feel the outcome was horrible if the 
> CW is declared elected. Using a phrase like "wins by a majority" creates 
> the false impression that a majority of voters favor this candidate OVER 
> THE FIELD of other candidates AS A WHOLE, whereas NO SUCH MAJORITY 
> necessarily exist for there to be a Condorcet winner. The concept of 
> Condorcet constructs many distinct majorities, who may be at odds, and 
> none of which actually need to like this Condorcet winner. I am not 
> arguing that the concept of "Condorcet winner" is not a legitimate 
> criterion, just that its normative value is artificially heightened by 
> saying the candidate "wins by a majority" when no such actual solid 
> majority needs to exist.
> Terry Bouricius
> ----- Original Message ----- 
> From: "Dave Ketchum" <davek at clarityconnect.com>
> To: <jgilmour at globalnet.co.uk>
> Cc: <election-methods at lists.electorama.com>
> Sent: Monday, December 22, 2008 7:23 PM
> Subject: Re: [EM] Why I think IRV isn't a serious alternative 2
> Disturbing that you would consider clear wins by a majority to be
> objectionable.
> In Election 2 Condorcet awarded the win to M.  Who has any business 
> objecting?
>       52 of 100 prefer M over D
>       53 of 100 prefer M over R
>       Neither R nor D got a majority of the votes.
> As to my  "no first preferences" example, surest way to cause such is to 
> be
> unable to respond to them.
> On Mon, 22 Dec 2008 10:18:34 -0000 James Gilmour wrote:
>>>>James Gilmour had written:
>>>>It MAY be possible to imaging (one day) a President of the USA elected
>>>>by Condorcet who had 32% of the first preferences against 35% and 33%
>>>>for the other two candidates.  But I find it completely unimaginable,
>>>>ever, that a candidate with 5% of the first preferences could be
>>>>elected to that office as the Condorcet winner when the other two
>>>>candidates had 48% and 47% of the first preferences.
>>>>Condorcet winner  - no doubt.  But effective President  -  never!
>>Dave Ketchum  > Sent: Monday, December 22, 2008 4:24 AM
>>>Such a weak Condorcet winner would also be unlikely.
>>>Second preferences?
>>>     That 5% would have to avoid the two strong candidates.
>>>     The other two have to avoid voting for each other - likely, for 
>>>are likely enemies of each other.
>>>     The other two could elect the 5%er - getting the 5%
>>>makes this seem possible.
>>>     Could elect a candidate who got no first preference
>>>votes?  Seems unlikely.
>>>I see the three each as possibles via first and second preferences - and
>>>acceptable even with only 5% first - likely a compromise candidate.
>>>Any other unlikely to be a winner.
>>>What were you thinking of as weak winner?
>>I'm afraid I don't understand your examples at all.  The "no first 
>>preferences" example is so extreme I would not consider it
>>realistic.  But, of course, if it were possible to elect a "no first 
>>preferences" candidate as the Condorcet winner, such a result
>>would completely unacceptable politically and the consequences would be 
>>The two situations I had in mind were:
>>Democrat candidate D;  Republican candidate R;  "centrist" candidate M
>>Election 1
>>35% D>M;  33% R>M;  32% M
>>Election 2
>>48% D>M;  47% R>M;  5% M
>>M is the Condorcet winner in both elections, but the political 
>>consequences of the two results would be very different.  My own view
>>is that the result of the first election would be acceptable, but the 
>>result of the second election would be unacceptable to the
>>electorate as well as to the partisan politicians (who cannot be ignored 
>>completely!).  If such an outcome is possible with a
>>particular voting system (as it is with Condorcet), that voting system 
>>will not be adopted for public elections.
  davek at clarityconnect.com    people.clarityconnect.com/webpages3/davek
  Dave Ketchum   108 Halstead Ave, Owego, NY  13827-1708   607-687-5026
            Do to no one what you would not want done to you.
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