1/2 votes: the false issue of "falsification"
Hugh R. Tobin
htobin at ccom.net
Fri Jul 12 23:43:01 PDT 1996
Mike Ossipoff wrote:
> In my previous letter I said that deterrence against falsification
> is taken away by compulsory contrary half-votes. But if we're
> talking about letting the voter have a choice about whether
> his ballot will be falsified, then the deterrence is still there.
> In that case, it's true what I said: Contrary to your claim,
> the Dole voter could get a worse result, in terms of his
> preferences, by having his ballot falsified as you proposed
> than he would otherwise get. That's because, as I said,
> the falsification can have the effect of order-reversal--
> it does include half of a reversed vote--and order-reversal
> tends to backfire badly in Condorcet--if voters are permitted
> to not have their ballots falsified.
Before I respond let me restate my proposal, cleaning up the misconverted
characters, but otherwise verbatim from the first posting:
" In Smith//Condorcet, I suggest the tiebreak based on who is
"least beaten" should count equal rankings or non-rankings under
the following principle:
In each pairwise contest between X and Y, count as 1/2 vote for X and
1/2 vote for Y an equal ranking of X with Y by a voter, if that voter
ranked all other members of the Smith set ahead of X and Y. Otherwise
count the ranking as 0 votes for each. (All non-rankings count as equal
1. The "false preference" is a false issue. A half-vote either way is
not an expression of preference at all between the two equally ranked
candidates. Still less can it be called a false preference, because it
is consistent with, and supports, the true preference of the voter to
have higher-ranked candidates beat either of the equally ranked ones. If
the Dole voters vote their half-votes between Clinton and Nader, that may
well put Dole over the top in the tiebreak, as I think it did in your
2. Unless I badly misunderstand the system, counting half-votes for equal
rankings cannot, like order-reversal, cause a circular tie. It is the
equal rankings, or truncations, themselves that may contribute to that.
Counting the half-votes matters only for the purpose of the tiebreak,
once there is a circular tie. My proposal, perhaps unnecessarily, said
that they would be counted only for that purpose.
3. Under my proposal counting the half-votes can never "backfire"
against a voter who sincerely ranks his preferences, including equal
rankings (that is the point of the way it is structured, and why it is
not equivalent to "margin of defeat"). The Dole voter (or any voter) can
get a worse result from having his equal rankings counted as half-votes
only if he actually does care which of his equally ranked candidates wins
in case his favorite does not -- that is, if he has "falsified" his vote
by ranking them equally, if one must use such loaded terms. (Even in
that case the half votes also might cause one of his higher-ranked
candidates, or his preferred equally ranked candidate, to win -- it
depends how everyone else votes.) Before we get too concerned about
the possible negative effect of the half-votes on this insincere voter,
it is well to recall that a voter who truncates when he really has a
second choice can hurt himself more directly, for example by electing his
last choice as a "false" Condorcet winner, without the half-votes making
any difference. The way for him to protect himself against the victory of
his least preferred choice is to vote his true preference -- indeed a
primary purpose of electoral reform is to give him the chance to do that,
without giving up his first place vote!
4. To sum up, it is choice of the zero option that would represent a
"falsified" non-preference, because it is a choice that (if rational)
reveals a voter's willingness to enhance the chances of defeat of at
least one higher-ranked candidate, A, in order to try to help a
lower-ranked candidate, B, prevail against one or more other candidates,
C, whom the voter has ranked equal to B.
This does not prove the zero option should be excluded. Perhaps it is
important in order to enhance the effectiveness of certain insincere
equal-ranking voting strategies that can be shown to have a positive
effect under some criterion, and for which there are no good
alternatives. I think that is the issue that deserves consideration.
-- Hugh Tobin
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