Approval vs Plurality?

[MIKE OSSIPOFF]

Steph--


I'd said:

>But I wrote those postings because you'd said that Approval violates
>1-person-1-vote, giving voters unequal amounts of power. You probably
>don't believe that Plurality violates 1-person-1-vote, and so I showed
>that actually Plurality gives more disparate voting power than
>Approval does.

You replied:

[...]

Approval violates "1-person-1-vote" according to my standards.

I reply:

I take it that what you say below is the standard that you're
referring to:

You continued:

It gives a slight advantage to voters who would put their approval cut-off
splitting candidates in two equal groups.

I reply:

>From what I posted on that, Approval can favor one voter over another
by a factor of 9/5, while Plurality can favor one voter over another
by a factor of 5. Thus, Plurality can favor one voter over another
by a factor nearly 3 times greater than Approval can.

Have you shown that there's a method that doesn't let voting power vary by 
as much of a factor as that by which it can vary in Approval?

No you haven't.

When you've found such a method, that would be a great
time to fault Approval because it lets voting power vary.

Anyway, if that's your standard for 1-person-1-vote, then that means
that Plurality violates 1-person-1-vote more than Approval does. And
if there's anything that violates it less than Approval does, you
haven't shown that.

You continued:

It artificially disfavours extreme
candidates.

I reply:

That's what you said before: You don't like electing voter median
candidates. And so when Approval, or Condorcet(wv), or Condorcet(rm)
elects a CW, it's artificially disfavoring the extreme candidates who
should have won instead of the CW. I guess I'm not quite sure what
you mean by "artificially". If you mean "as a result of the voting
system's properties, then I admit that Approval, Condorcet(wv), and
Condorcet(rm) artificially disfavor extreme candidates when they
elect voter median candidates.

But what you probably mean is that when Condorcet(rm) elects an
extreme candidate, in violation of majority rule, it's doing the right
thing, because it isn't artificially disfavoring extreme candidates.
But you can't count on rm always doing that. Often even it will elect the 
CW, and therefore fail your standard.

I emphasize that it isn't for me to disagree with your standard, though you 
should realize that you might have a difficult time convincing people choose 
your standard when it conflicts with much more widely-held standards.

On the other hand, you won't have any trouble selling your standard to
the IRV advocates, because they share your desire to not artifically
disfavor the extremes by electing the CW when majorities prefer the CW
to the extremes.

You continue:

But vote-splitting is by far a greater problem. So Approval is a lot better
than FPTP even if the latter does not violate "1-person-1-vote".
End of my logic.

I reply:

But if "1-person-1-vote" means what you said above, then FPTP violates
1-person-1-vote about 3 times worse than Approval does.

And if that isn't what you mean by 1-person-1-vote, then exactly what
do you mean by 1-person-1-vote?

Mike Ossipoff



Steph.




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