[Election-Methods] Simple two candidate election
Abd ul-Rahman Lomax
abd at lomaxdesign.com
Sat Dec 22 21:21:05 PST 2007
At 01:32 AM 12/22/2007, rob brown wrote:
>Your example is for more than two candidates.
Well, it might seem that way. But there are really only two choices
that make any sense. The third pizza type was in there simply to make
the normalization scores make sense. If it's not there, there is a
problem, and we will get to that.
> I am not questioning that when there are more than two
> candidates, it is a different situation. But there are plenty of
> possibilities for there to be an election where there really are
> only two candidates, and that is what my question was about.
Actually, that situation is rare in true democratic process. When it
happens, it is artificial, and typically represents a loss of
democracy, a compromise, which has been made in the name of efficiency.
> While I appreciate that most elections....at least political
> elections....may have more than two potential candidates, I was
> trying to restrict it to a simpler case.
But there is always a third potential option, which is None of the
above. In true democratic process, at face-to-face meetings, unless
special rules have been implemented (which Robert's Rules advises
rather strongly against), there is *never* a two-candidate election
where there is no third option, which is *no* result. The exception:
the two "candidates" are Yes or No. And even there a majority can
create any number of other options.
>Say your pizza voters are going to watch a DVD, and the only choices
>are the two movies from Netflix that are in the mailbox. It's
>really just two candidates sometimes.
But couldn't they decide not to watch a DVD at all? Maybe talk. But,
sure, if there are only two possibilities.... you then have a *real*
problem with what is called "normalization error" in the theory of
Range Voting.
>Of course in a small group there are much different
>dynamics. Reciprocity comes into play. People tend to be a lot more
>altrusitic towards their friends or people they are close to. I
>think these issues are quite a bit different in larger elections.
Rob is coming to a major point: the difference between elections in a
small group and in a large group. However, remember, above, he wants
to simplify the question. Now, it seems, there may be some desire to
complicate it. Yes, it gets more complicated in large groups. My own
work, in fact, is to treat this disease, the isolation and separation
of people that is the cause of this lack of "altruism." I don't,
myself, call it altruism: we all benefit from living in a society
where people care about each other.
However, if we are studying election methods, I would think that the
study would start with methods that work when people vote sincerely,
with concern for the public welfare. If a method does not work well
with people being honest and open and caring, how would we expect it
to work when under *difficult* conditions?
Obviously, the conditions are not the same, and thus, when applied in
difficult environments, special considerations may be needed. But,
remember the basic question here: simple two-candidate election. What
is the "best" outcome? Can the best outcome be found with a simple
majority vote on two candidates only?
It's quite clear that the *general* answer is no. Many examples can
be shown where the majority first preference, if we assume this is
how the majority votes in this case, is not the best outcome. But
this, then can raise the question Rob raised, of "fairness." I gave
the pizza example because fairness, in fact, *requires* that we set
aside the majority preference. It is not claimed that this would
*always* be true, but merely that the situations exist and are even
reasonably common where this is the case. Generally, most people will
agree to give up a small benefit in favor of a large benefit to
others. And life can get pretty ugly, pretty fast, when people don't.
I have the right of way, driving down a street, with some level of
traffic. I see a car coming out of a driveway, seeking to enter the
street. I could drive on, assuming that *someone* later would let
this car in, or maybe I don't care at all. Or I could stop and let
the car in. Small loss to me (and small loss to those behind me,
maybe -- maybe not, depends -- larger gain to the car needing to enter.
Now, democratic process is necessarily deliberative. Otherwise we
get, in fact, the "tyranny of the majority," without the majority
ever realizing what it is doing. If it's three people and that pizza,
they will surely talk about it, and they won't even vote, they will
find consensus informally. But what if it is three thousand people,
with one thousand people feeling just like each of the original
three? Does the best outcome change?
Whether or not there is a practical way to find that outcome is
another story. Range Voting is not an ultimate solution, full-on
consensus process is it. That, allegedly, suffers from serious
efficiency problems, but ... I look at that as an engineering
problem, and not a problem that is insoluble.
(I should say that "consensus process," to me, is not "everyone must
agree." Rather, it's a process which *values* the agreement of
everyone, and which seeks it. If the group size is large enough, or
if a small group is unlucky, there may be people who aren't going to
agree to something satisfactory to the others, no matter how much
time is spent on it. So how far does the group go?
My own answer is majority rule. The majority decides how much is enough.
But the majority will be likely to make wiser decisions if it is
informed about the true state of consensus in the group before it
votes on a binding decision. If I had my druthers, Range polls would
be very common, but not for making decisions; rather as part of the
deliberative process, and elections would be by majority vote on the
question "Shall so-and-so be elected to the office?"
That's a two-choice election, not "Shall we elect A or B," *unless*
the majority has previously decided that (1) the only legal
candidates are A and B, and (2) the election must be completed with a
single ballot. In my view, this decision is not true majority rule
unless the majority has made those decisions specifically about A and
B and this particular election. (Can a past majority bind a present one?)
> > For instance, could a two candidate election
> >be improved by, say, collecting information about how *much* each
> >voter likes or dislikes the candidates in question?
>Yes, absolutely, and it happens routinely in deliberative bodies.
>This is why the procedure is not Motion, Second, Vote! Part of the
>discussion reveals preference strengths, and members change their
>votes in accordance with that.
>
>
>Hmm, ok, well, is that really an election or more of a "lets all
>talk about this and agree to something"? It seems like all these
>situations are much more social, non-contentious places which are
>borderline for even having a vote.
The election is the last step, when a majority agree to the outcome.
Now, I ask this: why is it that Mr. Brown thinks of public elections
as something different from "let's all talk about this and agree to something?"
I can suspect this: it is because we have completely lost the sense
of public decision-making as a cooperative process, as a way that the
community finds unity and common purpose. Instead, it's a contest, a
battle, there are winners and losers.
Our political system is both the result of this and the cause of
this. Simply allowing voters to cast a vote for more than one
candidate, making Plurality into Approval, is a small step toward
healing this. I emphasize "small." I don't expect it to cause a huge
change, just a small one, there are other ways that we can reform the
system that will be more significant, and, in my view, these require
no changes in law at all.
>I see what you're getting at, but I just don't think the situations
>scale to larger numbers of people.
Based on what evidence? Again, my suspicion: Based on massive
cynicism about public process.
The simulations show Range Voting functions to improve overall
satisfaction with outcome, even with voters voting strategically.
(The whole concept of strategic voting in Range and Approval is a bit
of a red herring, as I've noted many times. A "strategic" vote in
Range is merely a strong opinion; there is no particular reward for
the strong expression of a weak opinion (that is, the reward, if the
expressed opinion is stronger than the supposed "real" one, is, by
definition, small, and there are risks of exaggerating; the system
might give you want you allegedly want -- or, more to the point,
might disregard your vote because, as to the two *real* options left,
you abstained by, say, rating them both zero.)
Approval was designed to be "strategy-proof," so critics ran a
linguistic trick on it. There really is no reward, ever, to insincere
voting in Approval, that is, to preference reversal. Rather, an
Approval voter will *always* vote selfishly and sincerely, they are
the same thing in Approval, for an Approval vote has one real
meaning: I will support *these* candidates, and I will not support
the rest. What is the strategy that Approval is alleged to be
vulnerable to? It is to vote for your favorite. And not for some
other candidate whom you allegedly "approve" of. Look at Tideman! He
analyzes ranked ballot data and assumes that if a voter has ranked a
candidate, the voter approves of the candidate, and that's the
"sincere" vote, then the tactical vote is if the voter can get a
better result by "burying" the lower-preferred candidates. Thus he
entirely invents a strategic vulnerability through voters, in fact,
voting sincerely....
Approval Voting rewards voters who understand the context in which
they are voting. But it does not harm the voter who simply votes for
his or her favorite.
An *election method* does not care about scale. That, in fact, is the
whole point about election methods. All the games that people may
play, in truth or in imagination, one a large scale can happen on a
small scale. Two people trying to decide what movie to see? One of
them could allegedly misrepresent his or her preference strength
against the favorite of the other. But what this boils down to as a
problem is that an unjust society is not going to generate just
decisions through election processes. Those two people have a problem
that is bigger than the movie decision; if they are husband and wife,
they are in trouble.
And if they are two hundred million people, half Democrats and half
Republicans (mostly), they are also in trouble if they will lie in
the thought that they will improve the outcome. Society breaks down
when we lie to each other, and, again, no election method is going to fix this.
But what I'm suggesting is that election methods that work when
people are honest are better election methods, and they won't make
things *worse*. Approval isn't going to change the outcome in the
vast majority of elections, not under current conditions.
But it opens the door to better process. Range is even better, for
obvious reasons; basically, it gathers more information from the
voter so that overall satisfaction with the result can be optimized.
Again, what is the problem with scale? Range critics allege that
Range breaks down due to strategic voting, but, not only do
simulations not show that, but there is no sound theoretical basis
for the allegation either. What I've seen essentially depends on
self-contradictory assumptions; the alleged failure mode is
bullet-voting *which is the status quo, enforced by regulation*. What
Approval and Range do is to create an *opportunity* for better
decisions to be made. And the "sincere" voter is not penalized, for
only weak preferences will be discounted. If I have a weak
preference, and I express that, and, as a result, my favorite loses,
one of two things is true: I won't care, because my expressed
preference was indeed weak, or I will be upset, in which case *I did
not express my true preference*.
>It is arguable, though, that there is nothing unfair about simply
>awarding the choice to the Range or Approval winner. In the case of
>Approval, the majority has given an explicit consent to this! But I
>prefer that the consent be to the actual result.
>
>
>I don't know, I think its a stretch to say that Approval gives
>majority consensus. To me giving "approval" is simply "picking
>candidates that are better than the other options". I guess some
>people interpret "approval" more literally than me.
The word "approval" is a red herring. The election system I was
talking about was Approval with explicit Favorite indication. That
is, the ballot is really three-rank: Favorite, Accepted, Disapproved.
Favorite and Accepted are each one vote. (If the voter votes both
Favorite and Accepted, it's still one vote, "Approval"). Favorite and
Accepted votes are then considered as ranked votes and a pairwise
victory of over the Approval winner is detected, which, if it exists,
triggers a runoff. (the situation that there are two or more pairwise
winner would need to be addressed, but I'd expect this to be
extraordinarily rare. Approval usually chooses the Condorcet winner,
it's expected.)
Then I was noting that, with Approval, if the winner has a majority
-- which is a little more likely than with Plurality -- the majority
has explicitly consented to the election of that candidate. If they
were not giving that consent, then, I'd ask, why did they vote for
the candidate? (This is much more obvious if there is a majority
election requirement, which is why that requirement is actually
really important, and why IRV when it is sold as a replacement for
runoff elections, but can then elect with the winner getting votes
from less than a majority of the ballots, as in recent San Francisco
elections, is really a problem, a loss of an essential principle of
democratic process.)
But, yes, it's cleaner if the consent is explicit. Robert's Rules'
solution is repeated balloting until a candidate gains a majority.
I'll note that this is a case where Plurality works fine. Approval
and Range would merely be a little more efficient.
(With Range it is necessary to define an Approval cutoff to
understand if the winner has majority approval.)
>
>
>Sometimes an assumption is made that "extreme" votes must be
>insincere or fanatical. While that is possible, Range and Approval
>never reward *truly* insincere votes; my contention is that if
>someone votes the extremes, they have a reason for it. Critics of
>Range will posit a "sincere" rating of 100 and 90 for two candidates,
>but the voter "strategically" votes 100, 0.
>
>
>Are those the only two candidates? If not, ok. If so, I don't
>understand what the numbers are relative to. All the people that
>might have run but didn't?
Ask the critics this question.
I was pointing out that this is a preposterous assumption. Anyway,
here is the example I had in mind, quoted from
http://www.fairvote.org/?page=1920
>Consider a range voting election in which 100 voters have the power
>to assign a score between zero and 99. There are two mediocre
>candidates. Of the 100 voters, 98 greatly dislike Candidate B, but
>decide to express their distaste for both candidates by giving one
>point to Candidate A and none to Candidate B. The remaining two
>voters prefer Candidate B and are more tactical. They award 99
>points to Candidate B and 0 points to Candidate A. The election ends
>with B beating A by a landslide of 198 to 98 despite the fact that
>fully 98% of voters preferred Candidate A.
>
>Explanation: This example illustrates how a tactical fringe can
>overrule a vast majority of voters when the majority votes sincerely
>and the minority votes tactically. Tactical calculations rise
>exponentially with the entry of more candidates, at which point
>winners also do not need to have been any voter's first choice.
This example is a little different from what I wrote, but it shows
the same thinking. Basically, the A voters decided to cast votes of
1/100 vote strength. They essentially abstained from the election as
an expression of "distaste." "The remaining voters prefer Candidate B
and are more tactical."
It would have been more accurate to say that they were more sane and
practical. They voted for their favorite and not for the less
favored. In Range 99, every voter seems to have 99 votes to cast, it
is really one vote, which they can cast in increments of 1/99. There
is nothing wrong with the outcome of that election, any more than
there would be anything wrong with deciding the same election in a
ranked method because the 98 voters declined to rank A and B and only
two voters voted for B. That is approximately what the A voters did,
and they would have no grounds to complain about the outcome in either case.
>To me it only makes sense to scale the values so the least favorite
>choice is 0 and favorite is 100.
Normally, yes. Normalization, it's called, and it is standard Range
advice. Vote 100 for your favorite, 0 for the most disliked. But
then, there is "strategy," i.e., considering the true environment.
These are votes, not expressions of sentiment, though certainly
sentiment may be a factor in determining them. The basic strategy is
to vote 100 for the favorite frontrunner and zero for the
least-favored frontrunner, then 100 for any candidate preferred to
the frontrunners and 0 for any candidate more disliked than both the
frontrunners. And then other candidates can be placed wherever you
like, for whatever effect you think you might want your vote to have.
>It's preposterous,
>really. Why does the voter do this? Because the voter cares that
>their favorite win. How much do they care? Enough to abstain from all
>other pairwise elections (since it makes no sense to rate a candidate
>zero and then rate a less-preferred candidate above zero. This is an
>abstention from every pairwise contest that does not involve the
>favorite.) That's enough to make it a sincere vote!
>
>
>Hmmm. Not sure where yo are going with this. Maybe I'm confused
>because the title of the thread is "simple two candidate election",
>and it appears we aren't talking about such a thing.
It's a general discussion, specifically applied in some places to the
2-candidate case. In the two-candidate case, "strategy" would
obviously indicate voting 100 and 0. However, strategy is not
everything. It is not uncommon to see people abstain from voting in
two-candidate elections, and for one basic reason: they have little
preference between the two. Range in a two-candidate election
*allows* a voter to abstain, like any other method, but it also
allows something new: a partial abstention, the casting of fractional
votes. On a theoretical basis, this should improve election
satisfaction, but it's totally voluntary. Every voter decides for
himself or herself whether or not to cast a full-strength vote, and,
in particular, I'd want to see that every voter knows that not voting
the extreme ratings for at least one candidate each is casting a weak vote.
It really is as if the voter was handed N votes to cast for each
candidate in an Approval election. Not casting N votes for any
candidate, but only casting M votes at most, is an M/N absention.
>
>Now, if the majority has only a weak preference for its favorite, why
>should the majority feel that something is unfair about another
>candidate, more strongly preferred by others, winning? If it bothers
>them, why didn't they vote against that outcome? Again, there is a
>contradiction.
>This contradiction exists so easily because we have for centuries
>thought only about rank, we have neglected preference strength in
>voting methods.
>With ranked ballots, we are quite rightly offended if a candidate
>wins who was not the preference of a majority,
>
>
>Not me. I don't even know what "the preference" means when there is
>a ranked ballot. I think the only place "majority" is important is
>when there are two options.
Yes. Which is an essential problem with elections when the elections
are not ratified by a majority. That ratification would be a Yes/No
question. If the answer is No, by a majority, the election fails.
Which the majority has explicitly decided. Leaving it up to a
"method" is a problem, but with some methods, consent to the result
may be implicit, and Approval is one of these. Range requires
something that is not part of standard Range proposals: an explicit
Approval cutoff.
> That's one of the reasons I brought up the "voting for a number"
> scenario, because it hilights the absurdity of being concerned
> about majority. Negotiation and compromise is expected, in my opinion.
No decision which has not been approved by a majority is democratic.
It's, at best, a compromise, made in the name of efficiency. Electing
officials is really just like any other decision, in principle.
Now, yes, with two candidates *and a presumption that the election
must complete*, there is little need for Range Voting; however,
Approval is still useful. Approval is really Plurality without the
overvoting restrictions. What's the difference? How could Approval
make a difference with only two candidates?
Well, if you want to know if a majority of those voting have accepted
the outcome, Approval is better. With Plurality and two candidates,
there will be a certain percentage of blank ballots and ballots with
votes for both candidates. What do those mean?
With Plurality, they are simply disregarded. But with Approval, the
blank ballots could mean that the voter disapproves of both
candidates, and the double-vote ballots that the voter approves of
both. Thus it becomes more possible to determine if there was a true
majority. At no cost, no complexity, no fuss.
As I've mentioned, we already have standard process for the
two-candidate case, with a majority vote required for either to win:
Ballot Questions. When two conflicting ballot questions are presented
in a single election, and both gain a majority, the one with the most
Yes votes prevails. There really is no difference between a
two-question ballot and an election with two candidates, with a
majority vote required to elect. Two conflicting decisions.
The claim of FairVote that Approval has not been used in public
electiosn in the U.S. is thus a bit misleading. Technically, it's
correct, as we might not think of Ballot Questions as "elections,"
but, then again, there is Bucklin Voting, which is "instant runoff
Approval." Which was pretty widely used for a time, and which
actually functioned well, my own suspicion is that it was shot down
precisely because it was working, just as was IRV in Ann Arbor. And,
for another oddity, FairVote cites a claim that early presidential
elections were a form of Approval, which is not actually true ....
but is merely ironic in light of the claim of no prior use.
To the main point here: the Majority Criterion is clearly suboptimal;
situations exist where *every voter* would agree that a different
outcome is better than their first preference *once they are informed
as to the preferences of other voters.* People like to agree, and
most people, making cooperative decisions, would greatly prefer to
have a decision that everyone thinks is fair, even if it was not the
first choice of a majority *as long as that first choice was not a
strong preference over the consensus one.*
I've participated in one group where the first preference of a
majority would have had about 70% support over all other options.
Until it was discussed and an Approval poll was taken, which showed
maybe 80% acceptability of that first preference, but 99%
acceptability of a new alternative. The motion was then made to adopt
the new alternative, and it passed unanimously. That's right. The
holdout changed her vote. This was a situation where one member of
this group had said that the change would be made (it was a
forty-year tradition, at least) would be "over her dead body." But,
then again, that was an organization that valued unity.
Now, shouldn't we?
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