[EM] NPV vs Condorcet

[Bob Richard]

Please provide a simple example of a Condorcet matrix synthesized out of 
an FPTP ranking. Apparently I'm not understanding this at all -- maybe 
there *is* a way to look at this that doesn't involve truncation.  But 
I'm very sceptical of any proposal that involves aggregating different 
voting methods in various subjurisdictions into a single result.

Thanks in advance.

--Bob

Kristofer Munsterhjelm wrote:
> Dave Ketchum wrote:
>> On Mon, 20 Oct 2008 19:51:55 -0700 Bob Richard wrote:
>>>  >     Some states may not be up to Condorcet instantly.  Let them 
>>> stay with FPTP
>>>  >      until they are ready to move up.  Just as a Condorcet voter 
>>> can choose to rank
>>>  >     only a single candidate, for a state full of such the 
>>> counters can translate FPTP
>>>  >     results into an N*N array.
>>>
>>> What would enforcing the truncation of rankings (to a single 
>>> ranking) for part of the electorate -- but not the rest -- do to the 
>>> formal (social choice theoretic) properties of any given Condorcet 
>>> method? Would the effect be the same for all Condorcet-compliant 
>>> voting methods?
>>
>> It is not a truncation.  It is interpreting FPTP ballots as if used 
>> by Condorcet voters.  Should result in pressure on all states to 
>> conform ASAP.
>>
>> I am ONLY considering FPTP and Condorcet  The exact Condorcet method 
>> cold be stated in the amendment.  Note that this is only a single 
>> national election, though there would be extreme pressure on other 
>> government uses of Condorcet to conform.
>
> If you're considering only FPTP and Condorcet, synthesize a Condorcet 
> matrix out of the FPTP ranking. That'll fix the consistency problems 
> with Condorcet, since if the other state's already Condorcet, you'll 
> be adding a real Condorcet matrix and not just a ranking.
>
> On the other hand, perhaps the state will use arguments similar to 
> those in favor of winner-takes-all and say "if our method says A > B > 
> C, then we have to maximize the chances of A winning, and failing 
> that, that B wins". I'm not sure whether the (hypothetical so far) 
> agreement should then demand Condorcet matrices, or if it should let 
> the states choose whether to use rankings instead.
>
> Range might be more difficult, since one can transform a rating into a 
> ranking (and a ranking into a Condorcet matrix), but not easily a 
> Condorcet result to a rating, or a ranking to a rating. Some Condorcet 
> methods exist that return aggregate rated ballot outputs (a rated 
> "scoring" instead of a social rank ordering), but they're very 
> complex; in an earlier post, I mentioned a continuous variant of 
> Schulze that uses quadratic programming.
>
> One solution to this might be to have states submit either a Condorcet 
> matrix or a range vector (n entries if it's plain Range, 2n if it's 
> with  Warren's no-opinion option). Then, at the end, all the Range 
> vectors are added and the Range result is computed for this. That 
> becomes one ordering, and a Condorcet matrix can be synthesized from 
> it. That artificial Condorcet matrix is scaled by the voting power of 
> the Range states and then added to the real Condorcet matrix, and the 
> result is given based on that.
>

-- 
Bob Richard
Marin Ranked Voting
P.O. Box 235
Kentfield, CA 94914-0235
415-256-9393
http://www.marinrankedvoting.org