[EM] [CES #4445] Re: Looking at Condorcet
rbj at audioimagination.com
Sat Feb 4 19:34:42 PST 2012
On 2/4/12 4:01 PM, Juho Laatu wrote:
> On 4.2.2012, at 19.14, robert bristow-johnson wrote:
>> so, i have a few questions for everyone here:
>> 1. do we all agree that every voter's franchise is precisely equal?
>> 2. if each voter's franchise is equal, should we expect any voter
>> that has an opinion regarding the candidates/choices to
>> voluntarily dilute the weight or effectiveness of their vote,
>> even if their preference is weak?
>> 3. so, based on the answers to 1 and 2, if there is an election or
>> choice between only two alternatives (yes/no) or two candidates,
>> that this election be decided any differently than, as we
>> were told in elementary school, the "simple majority" with
>> "one person, one vote"?
> My generic answer is that there is no single answer to how single-winner decisions should be made. Different elections may have different targets.
> In some elections / decision making processes people may voluntary dilute their vote. This approach typically means that the election is non-competitive.
> The properties of the environment, like competitiveness set some limits to what election methods can be used.
i've been assuming it's a governmental election and that it's
competitive. if it's not competitive, then it's either not important
enough for voters to have a stake in the outcome, or there is little
choice and everybody is pretty much in agreement. even in the latter
case, given the original restriction in (3.) that it's two candidates or
two choices and that one of those two choices must be made by some
deadline (normally Election Day), what situation can you think of, Juho,
where the decision-making rule would be anything other than the simple
majority of equally-weighted votes?
> Another criterion to what election method to use is how well each election method implements the targets of the election. The choice of the election method and collected information in the ballots thus depend on the targets and the environment. (Strategies could be seen to depend on the properties of the envionment and on how well a method can implement the targets in this environment.)
> I'll expand the pizza example a bit to demonstrate that there is a rich set of possible targets and ballot information. When a group of friends decides on which pizza to take or where to eat they quite often (unconciously) use a model where the range of opinions is not from 0 to max, but from minus infinity to plus infinity.
i'm sure that works really well when the mean-metric is used. problem
is, my opinion of George W Bush (-infinity) outweighs the opinions of
all those who voted for him. or maybe not.
> The scale has some fixed points that are linked to natual language. Such points can be "excellent", "not my favourite" and "pretty much unacceptable". Vote -inf means "impossible". Vote +inf means "the only possible alternative". With these values the outcome of the election / decision making process may be undecided (if two alternatives get +inf, or if some alternative gets both -inf and +inf, or if all alternatives get -inf).
so is undecisiveness a useful property for governmental elections?
> My answer thus is that in all three questions there can be different options. If someone asks me what single-winner method should be used, I'll probably ask what the targets and the environment are.
the environmental is: governmental election, two competitive choices
(yes or no on a ballot question, Romney vs. Obama, whatever). it's not
just pizza and the other voters are myriad and not necessarily friends.
but, even so, you and the other voters that aren't your friends have to
all live with the result. so: Two-choices, Competitive, Governmental
(stakes are high), Decisive (decision must be made by Election Day).
how're you going to do it? now those conditions are externally forced
but we'll add one more that we wouldn't have to, but we do because it's
fair: Equally weighted franchise. (if it's not equal, how do you decide
whose votes "are more equal than others"?) so your environment and
targets are constrained by all those conditions. what decision rule,
other than the simple majority of equally weighted votes can you (or
> A good definition of the targets should be detailed enough to allow also e.g. understanding what relevant information one expects the voters to have and express.
we'll get to that later (with the multi-candidate race), but what i am
first trying to settle is something more fundamental.
> The targets should also tell what alternative would be a good choice.
sorry, i don't understand tangibly what you mean here.
> With information like this it should be (in principle) a quite mechanical process to check all relevant available methods against the targets and environment description, and then pick the best method (and ballot format) (and guidance to the voters on how to vote).
really? okay so, with a simple well-defined environment: Two-choice
question, Competitive interests, High stakes, Decisive deadline, and
Equal franchise for every voter; then what further questions need be
settled to adopt a ballot format, tabulation method, and voter instructions?
r b-j rbj at audioimagination.com
"Imagination is more important than knowledge."
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