[Election-Methods] [EM] Juho--Schudy's statement is correct.
Abd ul-Rahman Lomax
abd at lomaxdesign.com
Thu Jul 26 12:25:59 PDT 2007
At 10:32 AM 7/26/2007, Steve Eppley wrote:
>I have time only for a few quick comments about Mr. Lomax' message (below).
>
>First, he appears to have misunderstood what I meant about altruistic
>voters. I asked what would happen if they voted sincerely (and selfish
>voters extremize). Somehow he misinterpreted that as if I'd asked what
>would happen if they misrepresented their preferences.
Sorry. The problem is in assuming a definite correlation between
selfish and extremizing. Extremizing is misrepresenting to the system
one's true preferences. It seems intuitively likely to me that the
*ideal* system would respond to such a voter by giving them what they
want, which has been distorted by their vote, so it can easily be
less than their true preferences would indicate.
However, we are dealing with Range Voting, and a particular kind of
Range Voting which we already know is less than ideal. Better than
most of what is on the table, but less than ideal.
Many consider that Range may, in many scenarios, reward extreme votes
to be a serious argument against it. I'd say that the arguments which
have been so made are incomplete, but that is really a side issue here.
The issue here is what the optimal strategies are in Range Voting.
There may be no general answer. I believe that I have found a case
where the voter optimizes personal utility by voting sincerely. I am
not *yet* claiming general application for this, but, contrary to
some assertions, this is not a small election. It can be as large as desired.
My conclusion comes from a more accurate determination of utilities
than has been happening with the simulations, it asks a different
question (there is a *specific* utility pattern involved, rather than
random distributions of patterns), and the simulations have been, it
turns out, Range 999999. It has been assumed by many that Range with
greater N is better. The proofs aren't in, as far as I know, very
little work has been done with *low* resolution Range. And my case is
maximally low resolution, almost Approval.
>Second, about optimal Range Voting strategy. It looks to me from my
>own analysis and that of others that, from the individual voter's point
>of view, the vote most effective at maximizing that voter's expected
>utility is one that extremizes (except in some unimportant rare cases
>where another vote can be as good.)
The case I propose is actually a quite general one, not truly rare,
the only thing rare about it is zero knowledge. We understand that if
the voter knows the election environment, and in particular, if the
voter faces, in spite of the number of candidates, a pairwise
election with high certainty, the optimal strategy extremizes *those*
votes. But what about the others? A sincere vote for a candidate who can't win
*cannot possibly lower utility,*
and there are other considerations besides winning. Votes have
effects. If a candidate is lousy, but has some support, Approval may
give that candidate very low votes. If the candidate gets twice as
good, there really may be no more votes. The real status of the
candidate is not revealed, as long as the candidate is not rising to
first place for a significant number of voters. As to second place,
we really need to know who is in true *third* place!
So the claim that intermediate votes are without value is clearly
false. The assumption is that all value is in determining the winner,
and that is false. People also value being honest and sincere, by the way.
What I am finding is that optimal strategy depends on the preference
pattern for the voter. We already knew that, didn't we? The claim is
being made that approval strategy is best (for the voter) *regardless
of preference pattern*. Is it? I have a counterexample. And it is a bit
> I haven't had time to hunt for Mr.
>Lomax' definition of optimality to check whether he defines it from the
>perspective of the (social utilitarian) voting system designer, rather
>than from the perspective of the voter who seeks to maximize his/her own
>utility.
The latter! We already knew that the optimal voting pattern from the
point of view of maximizing overall social utility is the sincere
vote. (Indeed, the optimal pattern is non-normalized sincere voting,
there is a way to define that).
However, the claim is that the voter has different utilities.
I must also point out that classic game theory falls flat, often, at
predicting human behavior, and often analysts assume that this means
that people aren't rational. However, many of the failures disappear
if we consider that people might be, within certain limits,
optimizing social utility. And we are not suckers, or altruistic, for
doing so, except with a very narrow definition of altruism. We are
acting to preserve our genes! And we are defining "our" as social
animals, who act for the welfare of the social group.
So even if it is true that optimal individual behavior is to vote the
extremes, many may choose not to do so. They will do so, I suggest,
when the loss in individual expected utility is small. We will rarely
lie when the reward for lying is small, for there is a cost to lying
entirely aside from game theory considerations.
In my view, extreme votes are not lying; they are, rather, truer
expressions of preference. If I want so much for a candidate to win,
A over B, that I will downrate B, *I may have a higher preference
than I was thinking.*
To my mind, a full vote preference does not have to be any particular
preference strength, in absolute terms. It's up to the voter to
decide! So I don't like to call extreme votes "insincere." For
convenience, I call simple expression of utility, generally
normalized, which is a distortion in itself, "sincere," with everyone
else. But it really means something more precise, such as normalized
accurate perception of utilities, or absolute perception of
utilities. In short, what I've called "fully sincere." For short.
By using the word "sincere," unfortunately, we call up all kinds of
moral judgements. We believe it is better for people to be sincere
than to lie or not disclose. But what is ironic to me is that, to
prevent some sort of reward for distortion, some of us want to
prohibit telling the full truth! Since some won't.
>Are we all agreed that extremizing is the (game-theoretically) optimal
>Range Vote in the case where there are only two candidates?
Yes. Not necessarily the "best" vote, but best for maximizing the
voter's personal utilities. Whether or not the voter wants to vote
that way is another story.
Consider the pizza election. With two flavors only, pepperoni and
mushroom. There are three voters (there can be *many* voters, but
let's say its proportional, my two voters are standins for twice as
many as the opposing faction.) Two prefer pepperoni, but only
slightly. The other, quite simply, cannot eat pepperoni, so we can
say that the preference strength is maximal. The lone voter obviously
should vote Approval style.
But what about the voters whose utilities are, say, 100 and 99? They
really do love mushroom, but pepperoni has only a slight edge?
What's the best pizza to choose? And does our voting method and
recommended strategy choose it? If not, we really should be
considering why not and what we might do about it.
That doesn't mean we can solve the problem. The problem is
artificially constricted if we limit ourselves to "election methods."
That's not how real groups would resolve this question.
Note that Range, with enough voters, won't always pick what I
consider the ideal pizza, it depends on how many voters and the
preference spreads. But Range+2 will.
Range+2 is top-two range, and it is known to outperform standard
Range in utility. And I think the simulations actually understate its
performance. Hold a Range+2 election with the two candidates (and
perhaps some others, doesn't matter; I originally stated the pizza
election as three to avoid the normalization problem, to allow
normalization without harm. In the two candidate case, normalization
can *drastically* distort the utilities.)
What will happen? Pepperoni and Mushroom will have a runoff. But the
pepperoni voters now know that there are many voters who have a
strong preference. They may elect to change their vote, to give up a
tiny bit of utility in order to make a huge difference for a few. We
do this all the time! We do it when we pay taxes that are used to
support people in dire need.
But if they judge that the strong preference is fake or not serious
or whimsical, on the part of the minority, they may stick to their
guns. And they will, quite properly, prevail, as they should have the
right to do. They are the majority.
All this, though, is dicta. The best personal utility optimizing
strategy for the 2-candidate case is extreme voting. However, when
the benefit is small, voters may well elect to simply vote sincerely,
understanding that this means that they may be giving up a small
benefit in favor of a larger benefit to a minority.
You could call that altruistic, but it is really social behavior.
These trades ultimately benefit everyone, for many interactions take
place, many choices, and if every one of them maximizes overall
benefit, and positions shift, as they do (it is not always the same
set of voters who are losing and who are benefiting), over time, if
net social utility is being maximized, so is personal.
So the optimal strategy *in one election* may be extreme voting -- it
certainly is for some cases, maybe even most -- but that is not
necessarily the best strategy for Life. Including elections.
And, properly, the decision is the voter's. Nobody should be telling
the voter what to do, the advice, unless it is purely informative, is
insulting.
Telling someone what their optimal strategy is insulting, unless
carefully specified. *If you want to accomplish A, then your optimal
strategy is ..." but, in that case, to avoid introducing bias, one
should also state the reasonable alternative goal, and maximizing
overall SU is the clear other option, leading to a different and,
indeed, possibly more pleasing strategy: vote sincerely and accurately.
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