[EM] IRV in San Francisco

[Dave Ketchum]

Still not into alphabet soup, seems to me what I wrote here deserves more 
response as to Nader.  The 35 Nader backers:
      Are strong enough to dream of winning - therefore voting Nader 
first, just in case.
      Hate Bush - therefore voting him last.
      Like what Condorcet does - agreeing with them that Kerry should win 
for being liked better than Bush.
      See IRV, treating Nader as a spoiler, failing to declare Kerry the 
winner.

The words below bother me:
      Seems like what afflicts IRV here is properly called a spoiler.
      Condorcet spoiler problems, if any, therefore differ from IRV's.

On Fri, 12 Nov 2004 13:47:26 -0500 I wrote:

> On Fri, 12 Nov 2004 13:06:23 -0500 Eric Gorr wrote:
> 
>> At 7:44 AM -0800 11/12/04, Justin Sampson wrote:
>>
>>> On Fri, 12 Nov 2004, Eric Gorr wrote:
>>>
>>>  > Well, it will cause IRV to fail the Independence of Clones 
>>> Criterion and
>>>
>>>>  thereby be subject to a spoiler effect again.
>>>
>>>
>>>
>>> Doesn't IRV suffer from spoiler effects anyway?
>>
>>
>>
>> Depends.
>>
>> The method itself passes the ICC, so spoilers cannot come from there.
>>
>> It, of course, fails IIA (as all ranked ballot methods do), so 
>> spoilers in this context still exist. Of course, since no ranked 
>> ballot methods pass IIA, talking about spoilers in this context is not 
>> very interesting.

>> Are there more directions from which spoilers can appear?
>> I am currently not aware of any.
>>
> I do not keep up with the alphabet soup, but IRV and Condorcet disagree as
> to winner in the following, and I see Nader as a spoiler for IRV:
> 
> 
> 40 Bush
> 35 Nader, Kerry
> 25 Kerry
> 
> Condorcet sees 35 Nader as ignorable and then 60 Kerry vs 40 Bush
> 
> IRV discards 25 Kerry; then sees 40 Bush vs 35 Nader.

-- 
  davek at clarityconnect.com    people.clarityconnect.com/webpages3/davek
  Dave Ketchum   108 Halstead Ave, Owego, NY  13827-1708   607-687-5026
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