[EM] 3 or more choices - Condorcet

[Juho Laatu]

What is a "strong" Condorcet method?

Juho


On 29.9.2012, at 23.11, Kristofer Munsterhjelm wrote:

> On 09/28/2012 10:11 PM, DNOW1 at aol.com wrote:
>> A > B
>> 
>> Choice C comes along.
>> 
>> C may - head to head ---
>> 
>> 1. Beat both
>> C > A
>> C > B
>> 2. Lose to both
>> A > C
>> B > C
>> 3. Beat A ---- BUT lose to B
>> C > A > B > C
>> 
>> Thus, obviously, a tiebreaker is needed in case 3.
>> Obviously perhaps Approval.
>> 
>> i.e. BOTH number votes and YES/NO Approval votes.
>> 
>> Obviously much more complex with 4 or more choices.
>> ---
>> ANY election reform method in the U.S.A. has to get past the math
>> challeged appointed folks in SCOTUS.
>> 
>> i.e. ANY reform must be REALLY SIMPLE.
>> --------
>> Condorcet applies for legislative bodies and single or multiple
>> executive/judicial offices.
> 
> I think Ranked Pairs is the simplest "strong" Condorcet method. You sort the pairwise victories so that the strongest comes first, then you go down the list, adding that victory to the final order unless it would contradict something you added earlier.
> 
> So say you have
> 
> 100 voters prefer A to B
> 80 voters prefer B to C
> 85 voters prefer C to A
> 
> which would give you:
> 
> First the result must place A higher than B. (Okay.)
> Second, the result must place C higher than A. (Okay.)
> Third, the result must place B higher than C... but that's impossible because C is higher than A is higher than B. So skip it.
> 
> And the winner is thus C. A comes second, and B third.
> 
> -
> 
> On the other hand, Schulze is being used more widely, so it's a question of what will be more persuasive: saying "this thing is simple", or "this thing is used lots of places".
> 
> ----
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