[EM] About non-monotonicity and non-responding to previous posts...

[robert bristow-johnson]

this is the 3rd or 4th time i forgot to hit "Reply All".  can the  
list admin *please* fix this so that the EM list is what is in the  
Reply-To: header?  i almost never remember to hit Reply All.

On Nov 5, 2009, at 9:30 AM, Kristofer Munsterhjelm wrote:

> robert bristow-johnson wrote:
>> being pretty much completely converted to the condorcet faith, i  
>> have no problem with non-monotonicity that happens to non- 
>> condorcet winners.  i still do not understand any realistic  
>> scenario where non-monotonicity affects the condorcet winner.
>
> What is your opinion regarding methods, such as Nanson, Baldwin,  
> and Raynaud, that are nonmonotonic when there is no Condorcet winner?

i dunno any of those methods (references would be nice, but i can  
google for them).  the only methods i know about are Ranked pairs,  
Schulze (but i haven't dug into the actual method to search out all  
beatpaths and rank them), Kemeny-Young.  i see that Nanson is on the  
list at Wikipedia, but not Baldwin nor Raynaud (at least by those  
names).

simplicity and sufficient transparency is important to have public  
confidence.  otherwise i would probably just jump on the Schulze  
bandwagon.

i don't think a sequence of elimination rounds would be okay, but the  
method of picking the biggest loser for each round needs to be  
debated.  i am not sure what would be best.

> Do Condorcet winners appear often enough in reality that it is not  
> a problem?

since no government yet uses Condorcet, i don't think any of us know  
the answer.

but for there to be a paradox, you would need a situation where there  
is no predictable voter alignment along a single dimensioned  
political spectrum.  you would need to have (in 2000) a lot of Nader  
voters who choose Bush over Gore as their second choice, and Bush  
voters that sincerely choose Nader over Gore, something i really do  
not expect.

while having *something* meaningful in law to deal with a Condorcet  
cycle, i really think that the lack of "the perfect solution" to the  
paradox problem (that likely will never happen in a real election  
with real candidates) should not be used as a block to adopting  
Condorcet in general.  what to do with a cycle can be adjusted at a  
later time.

and what we *do* know, is that it is not impossible, not even highly  
unlikely for IRV to elect a non-Condorcet winner, even when such  
exists.  there we have a method that chooses a winner when a  
*majority* of us voters have explicitly marked our ballots that we  
prefer some other *specific* candidate.  the reason i am such a  
Condorcet advocate is because the alternative, picking a winner who  
the electorate rejected in favor of someone else, simply is counter  
to any principle of democracy.

--

r b-j                  rbj at audioimagination.com

"Imagination is more important than knowledge."