[EM] Trees and single-winner methods
Abd ul-Rahman Lomax
abd at lomaxdesign.com
Thu Mar 15 08:18:58 PDT 2007
At 01:45 AM 3/15/2007, Juho wrote:
>I see candidate withdrawal related problems to be quite different
>from what I see in the proposed three based method. The biggest
>problem I see in candidate withdrawal is that if the person/group
>that makes the decision on withdrawal already knows the given votes,
>then it is possible to decide the winner in a small group, partially
>bypassing the opinions that the voters expressed in the ballots. This
>also opens the door to horse trading or even blackmailing. The
>proposed method at least is based on giving full information to the
>voters already before the election and letting the voters decide.
One person's horse trade is another's sensible compromise.
Suppose that an election is held and there are three candidates.
Let's suppose that the rules are approval and/or rull ranked, perhaps
Condorcet, but, as alleged by some could happen, everyone bullet
votes. And the three candidates have equal support. What would you do
with this election? Elect the candidate with the most votes, even
though that would mean electing a candidate who was only approved by
one-third of the voters? Or if there was an exact tie, choose the
winner by lot, which still has the same result -- a minority-approved
winner. And it could be a lot worse if there were more than three
roughly equal candidates!
Now, suppose that a candidate can reassign his or her votes to
another. If any two of these candidates can agree on who should win,
we'd have a winner who, for two-thirds of the voters, it is true that
they either chose the winner or the winner was chosen by someone who
they preferred as the winner. That seems to me to be *far* better
than choosing without such a reassignment.
And it could get even better if the candidates holding
redistributable votes are not limited to candidates who were in the
original election. That is, two of the original candidates could
possibly agree on a *different* candidate who, had this candidate
been in the election, would actually have gained a majority. Or at
least the two think that this is a good compromise.
Now, with Asset Voting, all this could be possible. I expect that
there would be *many* candidates and others perhaps holding write-in
votes; Asset Voting essentially creates an ad hoc electoral college,
without the inequities and other problems of the existing electoral
college. With many holders of vote assets, we essentially have a new
election process, but it can be fully deliberative. (I generally
consider bargaining to be an aspect of deliberation, but some
political scientists classify it as a third process, along with
aggregation and deliberation.)
Of course, you could do as some jurisdictions do: prohibit truncating
ballots, using a ranked ballot, and likewise prohibit equating
candidates (for equating in last place is equivalent to truncating, I
think). In other words, force them to choose. I find this highly
undesirable, actually offensive. It creates the *illusion* of a
majority winner. If we are going to create a minority winner, at
least we should be honest about it!
Now, suppose you don't like the possibility of secret deals. Aside
from making private communication illegal -- a cut off their arms to
prevent them from being broken solution -- secret deals can't be
avoided entirely. After all, a candidate can withdraw *before* the
election, based on some "secret deal." But consider an election
process that is Asset, *but* whatever result comes must be ratified
by the voters, if no majority winner emerged from the intial vote.
This would be somewhat similar to top-two, but without the
inflexibility of top-two (which can pass over a centrist candidate).
We have proposed that Range elections might have a ratification
stage, or possibly a runoff between the Range winner and a Condorcet
winner, if they differ. In this proposal with Asset, a runoff could
be between a winner agreed upon by a majority of recast votes under
Asset, and, say, a Range or Condorcet winner from the original
election. (I have not thought about how Range could be integrated
with this, I just mention it because it might be interesting.)
I disagree with those who refuse to consider deliberative process as
election methods. To me, an "election method" is a like a black box.
If we neglect the nomination process -- really we shouldn't -- we
have as inputs to the black box markings on a ballot from voters, and
the output is a choice between options open to selection. What
happens in between defines the election method. And deliberation could be used.
I've noted before that standard deliberative process actually
combines, if the participants want it, Range and Condorcet. The basic
process of someone moves that so-and-so be elected, the motion is
seconded, and then it is open to debate and amendment -- including
amendment to name a different candidate -- should, followed by awake
participants who can talk with each other -- select a Condorcet
winner even if all the votes are Yes/No. This is because the
participants can literally run every necessary pairwise election.
(Most of those elections wouldn't be necessary, so it would be much
more efficient than actually running every potential pairwise election.)
And it would satisfy Range with the provision that a majority could,
as we have often suggested, reject the Range winner if they were not
satisfied that the compromise involved was beneficial to the society involved.
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