[EM] Majority Criterion, hidden contradictions

[Michael Poole]

Abd ul-Rahman Lomax writes:

> At 11:29 AM 11/6/2006, Michael Poole wrote:
>>   By the majority criterion, a candidate X should win if a majority of
>>   voters answers affirmatively to the question 'Do you prefer X to
>>   every other candidate?'.
>>
>>A voter who cannot honestly or easily answer "yes" to some candidate
>>is not a problem for this formulation of the majority criterion.
>
> Note that Approval Voting provides a means of the voter expressing
> this preference. The claims that Approval does not satisfy the
> Criterion are based on a simultaneous assumption that voters "answer
> affirmatively to the question," but do not vote to express that
> answer. This is a contradiction.
>
> No voting method can use preferences that are not expressed.
>
> Linguistically, the Criterion contains a lost performative -- or
> something like that. *How* do the voters answer affirmatively. It
> could only mean that they so answer on the ballot. Which in Approval
> *requires* that they vote for  X and not for any other candidate. And
> if a majority of voters do this, that candidate cannot lose. So why is
> it said that Approval fails the Majority Criterion?

Nothing in the MC talks about what the ballot contains, only about how
voters answer a specific yes/no question.  Approval does not ask
voters to answer according to that question.  It fails the Majority
Criterion because if you add the constraint that each voter only
approves of one candidate, the system stops being Approval voting.

[snip]
>>When there are only two viable parties, Range Voting's use of strength
>>of preference apparently encourages the factions to be strongly (even
>>bitterly) divided: that will maximize the difference in scores between
>>the two candidates among supporters of each party.
>
> That claim is made. It's only true if the factions are already
> bitterly divided, have a strong preference for winning over maximizing
> the value of the election to the society. In other words, if the use
> of maximum range ratings is *real*.
>
> The effect is here asserted as the cause.
>
> We don't really know how Range will behave in actual elections. The
> only evidence we have comes from Warren's poll, and I consider that
> relatively weak. So confident assertions about how Range will behave
> are, quite often, premature.
>
> I don't see how Range *creates* the use of maximum scores in any
> pathological way.

There is currently a desperate shortage of politicians who prefer
society's good over their own continued time and power in office.  My
observations of the US political system (and, to the limit of my
lesser exposure to them, non-US political systems) make me think it is
naive to expect otherwise.

I am not arguing that Range creates the use of extreme scores (zero
and maximum), only that it encourages it to an extent that the result
is likely to be technically hardly better than Approval and
practically more likely to polarize factions.

The US currently has extremely polarized factions, and most of my
criticisms apply to plurality voting as well as to Range, but I would
rather replace the current system with one that seems robust in
practice rather than one that merely allows higher resolution of
polarization.

Michael Poole