[EM] [CES #4445] Re: Looking at Condorcet

[robert bristow-johnson]

On 2/9/12 5:19 PM, Juho Laatu wrote:
> Condorcet is a natural extension to the multi-candidate case (still 
> assuming competitive elections). Maybe not the only one though. In 
> another mail I just addressed the possbility of having single-winner 
> elections that aim at electing the winner from one of the major 
> parties (or more accurately, from one of the top two most 
> representative camps).

now why is that a good thing?  i thought that giving third and fourth 
parties (and independents) a level playing field is an intended 
consequence of the main virtue of ranked-ballot methods which is to not 
penalize the voter for voting his/her conscience and does not offer a 
reward (even if the reward is a consolation prize) for voting tactically.

> Condocet could however maybe be seen as the most natural extension and 
> a natural fisrt proposal for typical / basic single-winner elections.

that's what i thought from the beginning.  i remember when we voted for 
IRV in 2005 thinking that the language of the rules were not this 
natural extension and thinking "why did they adopt this method for 
dealing with the ranked ballots?".  but it occurred to me right away 
that all the pairwise champion needs to do is get into the final round, 
and he/she will win it.  so i thought it was probably unlikely that IRV 
would elect someone else.

>>   if Candidate A is the best candidate to be awarded office, that means that Candidate A is better than Candidate B.  it also means that Candidate A is better than Candidate C.  if Candidate A is the best candidate, it means that no other candidate is better than Candidate A.
>>
>> so, how do we determine who is better?  we could make them take an exam to show how much they know about job that the elected office entails.  or we could make the candidates arm wrestle.  but, in a democracy, the way we determine that one candidate is better than some other is that we ask the electorate.  sorta like Pilate asking the crowd to choose between Jesus and Barabbas.  the ranked ballot tells us who the voter chooses given any pair of choices.
>>
>> it's simple.  when a Condorcet winner exists, to elect *anyone* other than the Condorcet winner is the same as awarding office to the loser in a simple Two-candidate, Simple majority, One-person-one-vote election and i cannot see a *single* justification for doing that.  the "weak CW" argument does not cut it at all.
> For typical single-winner elections, yes. In special cases, like the one that I discussed above,

yeah, but i don't get why that special case is desirable.  why should 
rules be adopted that favors the top two parties as an end itself?

>   also other approaches may be possible.
>
> So I agree that Condorcet methods are a good first assumption (for competitive elections).

i just don't see the alternative (which is that you elect the loser of 
some pair of candidates).

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