[EM] CR style ballots for Ranked Preferences

Bart Ingles bartman at netgate.net
Wed Oct 3 23:32:59 PDT 2001

Jobst Heitzig wrote:
> Now as for the "trivial" and "important" preferences. This is nothing
> innate to preference ballots. It will always occur that in an election
> some people care more about what they vote and others less, so it will
> always be the case that "trivial" votes "cancel out" the more "important"
> ones. I think this is just a property of democracy unless you want to
> weigh votes.

Isn't that a bit like saying that death is inevitable, therefore disease
is immaterial?

The situation you're describing, where some voters don't care about ANY
of the alternatives, is unavoidable in any socially acceptable voting
system.  We always assume that voters have an equal say (by some
defensible definition of "equal say").

What I'm talking about is avoidable noise -- such that a rational voter
would willingly give up having some of his less important preferences
counted, with the understanding that the same limitation would apply to
other voters, in hopes of increasing his expected utility of outcome.

Of course not every voter could have is utility expectation improved
this way -- if you were a member of an obvious political minority, you
might be better off obscuring the results with as much non-essential
information as possible.

> However, one might argue that in pluratlity elections those voters
> whose preferences are not enough important (that is, those voters who do
> not care enough) will simply not cast a vote at all, while with preference
> ballots they have to rank all or none of the alternatives, even
> those they feel they don't know enough about to make a reasonable choice
> between them.
> I consider this a very profound disadvantage of "classical" preference
> ballots. There is however a *very simple* (at least theoretically) way to
> solve this problem:
> || just allow voters to express that they are "UNDECIDED" about certain
> || pairs of alternatives. In other words: do not assume that individual
> || preference relations are complete, but allow them to be any quasi-order
> || (that is, any reflexive and transitive relation). One can even allow
> || cycles in individual preferences!

That's a given -- I expect that very few participants on this list favor
requiring ballots to show strict preferences.

But it may not be enough to simply allow voters to express undecidedness
or indifference, if there is no incentive to do so.  Otherwise, if the
actual preferences are weak, then tactical considerations will drive the
voter's expressed ranking.  In other words, if I prefer A, and am nearly
indifferent between B and C, then you can expect me to rank B and C in
whatever way best helps A.


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