[EM] Re: The Allure of IRV

[Dave Ketchum]

I got into this thread because of comments as to what voters might understand.

So, I put my voter hat on again to respond to the following.

On Sun, 28 Apr 2002 11:32:16 -0700 Richard Moore wrote:

> Dave Ketchum wrote:
> 
>> I claim that approval is both weak enough for many of these to notice, 
>> and more difficult than its backers are willing to admit:
>>      Weak because, if I approve of two candidates, I CANNOT indicate 
>> my preference between them.
> 
> 
> I cannot buy the notion that this is a real disadvantage. Is being
> required to choose between approving one candidate, vs. expressing a
> preference for another candidate over that candidate, really an
> unacceptable burden to impose on voters? If you believe it is, can you
> tell me why?


I do not see this topic as burdens.  All the methods under discussion 
require me, as a Nader backer, to indicate my preference between Bush and 
Gore if I want to be part of that expected decision.  Approval denies me 
the power to BOTH indicate my Bush/Gore choice AND indicate that, should 
Nader become one of the finalists, I prefer him over the competition.

> 
> Preferences that are expressed in Approval tend to be strongly held
> preferences, while preferences that are expressed in ranked ballots
> are of unknown strength (and sometime negative strength, particularly
> in non-Condorcet methods such as IRV and Borda). Thus, the voters may
> end up with a CW who is favored by a majority of voters to all other
> candidates, but who doesn't have any voters that have a strong
> preference for that candidate over their next choice. When the CW and
> the AW (Approval Winner) are different, the better choice is probably
> the AW, since it is likely that, for the majority that prefer the CW
> to the AW (as indicated on rank ballots), that preference is a weak
> one -- otherwise that preference would be expressed in the Approval
> vote as well. For the minority who approved the AW without approving
> the CW, this was more likely to be a strong preference.


I get dizzy, and suspicious, trying to sort that out.

> 
> Approval does sacrifice individual expressivity in order to gain group
> expressivity, but after all when we hold a public election we are
> trying to make a social choice, not a private choice.


Truly the decision as to winner is a public choice, but it needs to be, as 
close as possible, the sum of the private choices of the voters.  For that 
to work, knowing more of what each voter's private choice is needs doing 
so far as practical.

> 
> If it's individual expressivity you want, then Cardinal Ratings are
> for you. You'd be perfectly free to sacrifice instrumental voting power
> to make a more exact statement about your evaluation of the candidates'
> merits.


This one scares me.  I would worry about losing to those who could figure 

out a strategy to give themselves extra power over those of us who are 

not up to strategy.
> 
>>      More difficult because where, in the scale between like and 
>> dislike, is the point where I should stop approving candidates?
> 
> 
> If you are unable to decide whether to approve or disapprove some
> candidate, because that candidate is somewhere close to the strategic
> borderline between approval and disapproval, then the strategic value
> of your vote for that candidate is close to zero (relative to your
> strategic values for the high- and low-utility candidates). Therefore
> the strategic cost of making the wrong choice on this particular
> candidate is very low.


I think you are saying it is not important whether I get it exactly right 
- could be, but I am not sure where the ballpark is, to be close to being 
right.

Adam was more helpful, with a rule I could follow:  Approve whichever 
candidate I prefer among the expected front runners, and approve all the 
candidates I like better than that one.

> 
>  -- Richard

-- 
  davek at clarityconnect.com    http://www.clarityconnect.com/webpages3/davek
   Dave Ketchum    108 Halstead Ave, Owego, NY  13827-1708    607-687-5026
              Do to no one what you would not want done to you.
                    If you want peace, work for justice.

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