[EM] To Bill Lewis Clark re: stepping-stone

[Dave Ketchum]

On Sat, 24 Jan 2004 17:28:28 -0800 Bart Ingles wrote:

 > Adam H Tarr wrote:
 >
 >>AS LONG AS you have two major factions that have comfortably more than two
 >>thirds of the first-place preference between them, IRV does a good job of
 >>preventing minor party candidates from "interfering" in the two party 
system.
 >>In this respect, it manages to solve the "spoiler" problem in its most 
commonly
 >>described form (i.e. the extremist party leeching votes from one of the 
major
 >>parties).
 >>
This can be said a bit tighter, AND more correctly:  Sorting votes by
first-place preference into C1 (most), C2 (next) and Rest; if C1 has a 
majority, C1 wins; else if C2 receives more votes than Rest, C1 or C2 will
win, depending on lower preferences in Rest votes.  While this is true for
both IRV and Condorcet, they differ as to how lower preferences are analyzed.

As a troublemaker, I look around until some district manages:
49 A
25 B,C
20 C
  6 D,C
By my count:
      A and B have 74% - well over 2/3.
      IRV and Condorcet will AGREE to award the win to C.
      Of course, likely that A and C were the major factions, with some 
dissension within C.
 >
 > You could also argue that so long as the above condition holds, the
 > "lesser evil" strategy is obvious, and so no mechanism is really needed
 > to solve the "spoiler" problem.  We may call Nader the "spoiler" because
 > we have no better term, but the truth is that Nader didn't force anyone
 > to vote a certain way.  Anyone who voted for Nader thinking he had a
 > realistic chance of winning was either too crazy or too uninformed to
 > have any business voting.  It's probably a safe bet that almost everyone
 > who voted for Nader (at least in a competitive state such as Florida)
 > didn't much care what happened between Bush and Gore, and placed a
 > higher value on placing a protest vote.

Interesting, but not especially valuable:
      In this Plurality election, you could not vote for Nader without 
losing the ability to vote a preference for Gore over Bush,
      With ranked ballots everyone who preferred Nader could have voted 
for him AND also have voted in Gore vs Bush - meaning that you approach 
voter desires in their first-preferences.
 >
 > As an aside, it's not clear to me that Gore would have netted anything
 > in Florida if IRV had been used.  Of the 1% or so Nader received, some
 > voters would have named either Bush or NOTA as the second choice.  So
 > Nader might have gained 1/8 or 1/4% against Bush from this group.  But
 > then Bush would have picked up additional votes from the Buchanan and
 > Libertarian voters.  So I wouldn't want to bet on whether IRV would have
 > changed the final outcome.

Could be - but we go for ranked ballots to let voters express their 
desires more completely - which OFTEN makes a difference.
 >
 > Bart
-- 
   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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