[EM] Highly-expressive preference voting

[James Kislanko]

Y'all are still jumping into areas I didn't mention. 

Succinctly, all I'm saying is that you cannot derive my personal pairwise preferences from a ranked ballot. I'm not talking about the even more complicated question of counting votes.
Given more than 2 "issues" I might rank A>B>C>D>E given 5 choices, but asked whether I prefer C or D might choose D based upon the only subset of the issues where they disagree. You can build up a pairwise matrix from my pairwise choices, but you cannot infer my pairwise preferences from something that isn't pairwise.
The list (and literature) is full of examples of why my ranked ballot may not match my pairwise preferences: maybe I put C>D because that would help A. But if A, B, C and E were NOT running I'd prefer D. 

A decade or so ago I tried to point this out in the context of someone describing a "condorcet election" as being the same as a "round robin" tournament. It would be if the voters got to choose between each pair of alternatives (THAT would be a "round robin") but it is logically incorrect to infer from an ordered list that the voter's list would always be the same for all subsets of that list. 

Personally, I'd like a voting method that gave me pairwise choices, like my opthalmologist's "better or worse?" tests when trying to figure out what eyeglass prescription to write. Just record my answers in a matrix and sum all voters' matrixes. Then you can count the result however you want but I'll know that my pairwise choices weren't made by you.
 


     On Sunday, August 30, 2015 3:07 PM, robert bristow-johnson <rbj at audioimagination.com> wrote:
   

 On 8/29/15 9:24 PM, James Kislanko wrote:
> I cannot respond to what you describe, since it has no relevance to 
> what I said, which is there is no ranked ballot that can reproduce my 
> pairwise preferences if I use different criteria depending upon what 
> the pairs are.
>

i can't really decode this, James.

we all understand that with a population of voters, a Condorcet cycle 
can possibly result (Rock>Scissors, Scissors>Paper, Paper>Rock) and then 
you need to add something or have something more, in the tabulating 
criteria, to determine a winner.  (i actually think a cycle would be 
rare in real governmental elections using a ranked ballot.)  people on 
this list can argue which is best.  probably most agree that Schulze is 
best, but i think that if the cycle contains only 3 candidates, that 
Schulze and Ranked-Pairs (margins) and MinMax all pick the same winner.  
Ranked-Pairs is a helluva lot easier to explain to skeptical legislators 
and others i might try to convince to re-adopt the ranked ballot (but 
this time *not* to go with IRV), so i have been sticking with that.  
(and, as rare as a cycle might be, i think it would be even more rare 
for a cycle to have more than 3 candidates in it, so the difference 
between a Schulze and Ranked-Pairs might seem moot.)

but just because the collective vote totals might result in a circular 
preference, that doesn't mean that it's reasonable for a single voter 
to.  if a voter prefers Candidate Rock over Candidate Scissors and the 
same voter prefers Scissors over Paper, i cannot grok how this same 
voter could possibly prefer Paper over Rock.  then a single, linear, 
ranked ballot works fine in recording all of the contingency vote 
preferences of that voter.  the rest of the problem is taking all of 
this collection of ranked ballots, and with the principle of "One Person 
One Vote" determining what the collective preference of candidates is 
and identifying the winner.  outside of a cycle, i think that Condorcet 
works pretty well because, as long as there *is* a Condorcet Winner, 
that choice would prevail in any hypothetical one-on-one election and 
not the reverse.

people here since 2009 might remember when i joined the list and that i 
lived in a municipality with a strong 3rd party (the Progressive Party 
of Vermont), we had IRV for our mayoral election and, while a majority 
of voters marked their ballots that they preferred Candidate A (for 
Andy) over Candidate B (for Bob), nonetheless Candidate B was elected.  
a year later IRV was repealed, although a wide majority of voters didn't 
understand exactly what went wrong (and would dispute the problems), 
enough folks knew *something* was wrong and IRV and it was repealed and 
unfortunately along with it, the ranked-order ballot.

so, please elaborate on exactly what you mean.

r b-j

> On Saturday, August 29, 2015 4:46 PM, robert bristow-johnson 
> <rbj at audioimagination.com> wrote:
>
>
> On 8/29/15 6:17 PM, James Kislanko wrote:
> > This example is a perfect demonstration of what I tried to describe a
> > decade or so ago.There is no way to make a linear ordering of pairwise
> > preferences if the voter uses different criteria depending upon what
> > the pair is. I'd like my contribution to the pairwise matrix be based
> > upon a ballot that gave "A or B, neither?" for every combination of
> > choices.
>
> while IRV ballots seem to prohibit marking two candidates equally
> (except for those unmarked, who are all tied for last place preference
> on that particular ballot), there's nothing in a Condorcet ranked-ballot
> to stop you from marking A and B equally, whether they be first or last.
>
> how is
>
>  A = B = last place
>
>    any different an expression from "neither"?
>
> ranked ballot, in which tied ranking is allowed, is the most sensible
> form of expressive preference voting.  score voting requires too much
> "expression" from the voters and approval voting too little.




-- 

r b-j                  rbj at audioimagination.com

"Imagination is more important than knowledge."



----
Election-Methods mailing list - see http://electorama.com/em for list info


  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.electorama.com/pipermail/election-methods-electorama.com/attachments/20150831/3ee35517/attachment.htm>