[EM] Majority Criterion poor standard for elections
Abd ul-Rahman Lomax
abd at lomaxdesign.com
Mon Oct 23 19:33:32 PDT 2006
On the Range Voting list, there has been an interesting discussion of
the philosophy behind Range Voting vs preference-based methods (such
as those satisfying the Condorcet Criterion and the Majority Criterion).
From Wikipedia:
>The majority criterion is a
><http://en.wikipedia.org/wiki/Voting_system_criterion>voting system
>criterion, used to objectively compare
><http://en.wikipedia.org/wiki/Voting_system>voting systems. The
>criterion states that if a majority of voters strictly prefers a
>given candidate to every other candidate (i.e. the given candidate
>is the first preference of more than half the voters) and they vote
>sincerely, then that candidate should win.
I should really touch that article, for the term "objectively," while
technically correct, implies something that is not true: that systems
which satisfy the majority criterion are superior to those which do not.
The problem with the majority criterion is that it entirely neglects
strength of preference. Warren Smith, in his writing about Range
Voting, has pointed this out: for some voters, the choice may be a
matter of life and death, and for others, it may be a mere
preference, or even no preference at all, the voter tossed a coin....
If a group of people for some reason can only order one kind of
pizza, how can they choose which kind? Range Voting, where each
person votes a numerical value for each choice, Warren prefers
systems that are 0-99, but technically Range includes systems all the
way from Approval Voting (value integers from zero to one) to even
more refined systems, such as one where, in comparing items, the
voter may assign any number and then the scores are normalized so
that the highest vote given reduces to the maximum in whatever system
is used to compile the votes.
For some people, whether or not they choose pepperoni may be only a
matter of whim, they like some of the other choices just as well,
though maybe that particular day they have a preference. For others
it may be very, very important: pepperoni may make them ill or may be
religiously prohibited. If you care about the group welfare, Range
Voting essentially maximizes group satisfaction.
The Majority Criterion, I could show, also causes the voting system
to devalue, effectively, the votes of knowledgeable voters, making
them equal to those of those who are not knowledgeable. While we
often think of strong opinions as representing fanaticism, the fact
is that those who are knowledgeable about a subject are likely to
have much stronger opinions about it -- so strong that their opinions
may even be admitted as evidence, "expert opinion," -- than those who
are not informed. When the uninformed have strong opinions, we would
hope that these opinions could be given less weight, but I see no way
to do this without violating the basic criteria of democracy;
however, a rational system would at least allow voters to indicate
how strong their preferences are.
And if the voting system takes into account strength of preference,
it does not satisfy the majority criterion.
A proposal has been made that if a Range poll shows a different
winner, by summation of votes, than would be indicated through
preference analysis -- which is easy to do with Range votes -- then
there would be a ratification poll. Thus the Range winner would never
be imposed on a majority, and the overall system would, indeed,
satisfy the intention behind the Majority Criterion.
The Condorcet winner could, quite easily, not be the winner who would
maximize social satisfaction with the result....
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