[EM] [CES #4445] Re: Looking at Condorcet

[robert bristow-johnson]

responding to both Andy and Kristofer...

On 2/6/12 2:31 PM, Andy Jennings wrote:
> On Sat, Feb 4, 2012 at 10:01 PM, robert bristow-johnson 
> <rbj at audioimagination.com <mailto:rbj at audioimagination.com>> wrote:
>
>     i really don't want this question distracted too much with "the
>     guys and i are going out for pizza."  a little bit of distraction
>     was okay, but the give-and-take relationship with my
>     pizza-and-beer buds is just not the same as in a partisan contest
>     that i bring my mace and shield.
>
>
> It was, admittedly, an extreme example.  But a hyper-bitter cutthroat 
> political contest is the other extreme.

but, even if they are not hyper-bitter, people do not like finding out 
after the election that the election method had an "anomalous result" 
(meaning that it elected the "wrong" candidate, in some sense of the 
word) and, from a more objective POV, the election punished their honest 
vote or would have rewarded a tactical vote by sufficient numbers.  it's 
just any old political contest that is really *contested*, not some 
cooperative organization where everyone is thoughtfully thinking about 
"what would be the best for everyone?"  if the community gets big enough 
and the stakes get high enough (but not yet cutthroat), no one wants to 
experience that.

this is the whole point of why i hang around this mailing list.  this is 
what i think election reform is good for and this is why i am nowhere 
close to convinced that either a traditional FPTP, nor Approval, nor 
Score voting cuts the mustard.  all's the voter wants to do is vote for 
his/her favorite candidate without finding out later that this vote 
harmed his/her political interests.  in order to do that, you *have* to 
collect contingency vote information (the ranked ballot), but you need 
not add the additional burden to the voter as to how high they should 
rate their 2nd choice so as not to harm their 1st choice and not to help 
their last choice.  and, for Approval, it's the same problem because the 
voter has to decide whether or not to approve of their 2nd choice.  and 
we all know the problem with the traditional ballot with 3 or more 
candidates.

>   There are shades of gray in between and there are many elections 
> that fall nearer the pizza example than the mace and shield one.

it has to be a small and fairly homogeneous community.  and i think 
eventually someone is going to feel their political interests are 
getting short shriff and the time of "playing nice" has past.  then the 
elections become contentious and competitive and then i just don't see 
any good to asking voters to voluntarily dilute their "one person, one 
vote" from what they are allocated as one person.  and with the 
additional burden of tactical voting (what to do about your 2nd choice) 
that makes either the Approval or Score ballot undesirable in a 
governmental election.


On 2/5/12 5:07 PM, Kristofer Munsterhjelm wrote:
> ...
>> that is not well defined. given Abd's example:
>>
>>> 2: Pepperoni (0.61), Cheese (0.5), Mushroom (0.4)
>>> 1: Cheese (0.8), Mushroom (0.7), Pepperoni (0)
>>
>> who says that for that 1 voter that the utility of Cheese is 0.8?
>
> The voter does. In this thought experiment, one simply assumes the 
> 1-voter's utility of Cheese is 0.8 so as to show the point. The point 
> is that there may be situations where utilitarian optimization and 
> majority rule differs.
>
>> how is that function defined in the "proof" that Clay repeatedly 
>> refers to
>> where "it's a mathematically proven fact that Score does a better job
>> picking the Condorcet winner than does Condorcet"?
>
> It isn't. Warren's argument that "Range is more Condorcet than 
> Condorcet" is quite different. I assume Clay is using that argument 
> when he claims "Range does a better job", but I don't know as I 
> haven't seen Clay's arguments.
>
> The first part of the argument is that, in the real world, people will 
> have access to polling data. Then, Warren argues, this means they will 
> act strategically.

They *may* anyway.  What evidence does Warren or anyone have that, given 
advanced polling data and knowledge that the election will be decided by 
Condorcet, that they will vote strategically in greater numbers, or that 
voters can expect to game the system anymore with Condorcet than they 
would with Score or Approval or FPTP or IRV?

but we *know* what can happen with FPTP and IRV.  we've seen it.  we 
*know* that Approval and Score burdens voters with the question of what 
to do with their 2nd choice where the ranked ballot does not, in and of 
itself.  some methods of tabulating the ranked ballot *do* demonstrate 
and have demonstrated anomalies that can reward tactical voting.  but, 
whenever Condorcet is critiqued, it is with some pretty weird and 
contrived examples where voters do something *very* chancy, like burying 
their **2nd choice**!!  WHY would you *ever* want to take the chance and 
bury your 2nd choice if you are not assured your 1st choice will win???  
even if you are confident your 1st choice will win, why bother to bury 
your 2nd choice?  so you guys have dreamed up weird and unlikely 
situations where some candidate in the "Radical Center" encourages his 
voters to bury the other centrist candidate who might also be the 
Condorcet winner.  but that's taking an awful big chance.  how are 
scenarios like this likely enough to trump the obvious reason for 
Condorcet which is to avoid a simple negative result: electing a 
candidate when more of us wanted another candidate to be elected.

i don't get it.

> Say that X is the honest Condorcet winner (and polls show that he is). 
> Then, according strategy, "anybody-but-X" people would rank X last. 
> Depending on the method and X's margin of victory, that could make 
> some other candidate win,

not with any confidence!  you might just blow it and hand the election 
to someone that everybody hates.  i just don't see that sorta nefarious 
voting strategy as having *any* appeal at all.  because of it's 
unlikelihood, because of the unlikelihood of a cycle, i just don't see 
what all this fuss is about.  i really don't see it likely at all that 
people will either try to game Condorcet nor will people need to revert 
to the tactic of "compromising" in Condorcet that we *know* they do in 
FPTP and that IRV encourages.

...

> If you want to specify the proof further, you could say it really says 
> this: "if more than a certain fraction strategize in both the 
> Condorcet method and Range, if Condorcet strategy involves burying the 
> sincere CW if you prefer someone else, and Approval strategists know 
> who the top-two are, then Range elects the sincere CW more often than 
> does the Condorcet method".

it's not proof!  it's based on the assumption that people *will* try to 
game Condorcet that way, even if it's Russian Roulette.  i don't get 
this argument at all.  again, we know how people are burdened by the 
compromising tactic with other systems, but this notion of nefarious 
tactics by people who twist their mustaches to get their favorite (whose 
otherwise a loser) to beat an honest CW is far fetched.

> What if fewer people than that fraction strategize? Then Range will 
> elect the CW less often than the Condorcet method, but then Warren 
> refers to utilitarian reasoning and says: if people are mostly honest, 
> then the normalized Range values are based on their true utilities, 
> and thus the Range winner will have greater utility than the Condorcet 
> winner, since the Condorcet method knows nothing about utility.

Warren can say that, but saying it isn't proof.  who knows what people 
will do in the privacy of the voting booth?  is it *dishonest* (or 
compromising) to vote for one's 2nd choice over their 1st choice?  who 
really does employ burying and realistically expect to gain advantage by 
such?

>> so, i have a few questions for everyone here:
>>
>> 1. do we all agree that every voter's franchise is precisely equal?
>
> Yes.
>
>> 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?
>
> In a pizza scenario, voters might voluntarily dilute their weight to 
> be nice to the others. In a hotly contested governmental election, not 
> as likely.
>

as i confirmed to Andy, it's governmental, it's competitive, and the 
stakes are high enough that no one wants to dilute their vote.

>> 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"?
>
> Those using utilitarian reasoning would say that if the prerequisites 
> hold (people know their utilities and they're commensurable), then a 
> utility-optimizing outcome is better than a majoritarian one.

remember, it's two-candidate or two-choice race.  so there is some 
utilitarian reasoning that accepts that all voters' franchises are equal 
and that no one wants to dilute their vote (because the outcome is 
important to the voter) and that this utilitarian reasoning conclude 
that awarding the election to the loser, the candidate or choice with 
the fewest votes, is optimum?

> I think Warren uses a "tyranny of the majority" example in this case...

i remember last spring arguing with an anti-IRV Democrat that also 
apposes raising the 40% threshold to 50% (to preclude a runoff) that, 
with a straight face, tried to sell me this "tyranny of the majority" 
baloney for why we should elect a minority candidate and why there are 
instances where it's preferable to let the minority rule.  i think it 
was really bullshit.  this "tyranny of the majority" problem is either 
one about basic human rights that get codified in a "Charter of Rights 
and Freedoms" or something like that.  or it can be about putting a 
little bit of hysteresis in government decision making and requiring 
some super-majority to change certain policies.

but the notion of "tyranny of the majority" is no reason that you award 
office to the loser in a two-candidate race.

> One could of course argue that in cases like tyranny-of-the-majority, 
> the majority would just vote strategically to override the minority.

of course.  it's a trivial example of how anomalous or perverse election 
results will create an incentive to vote strategically.  if the loser 
wins, then vote for the candidate you don't like and your favorite will 
be the loser and gain office.  duh.

then how does *anyone* claim that, given those conditions above 
(Two-choices, Governmental with reasonably high stakes, Competitive, 
Equality of franchise), that you decide the election any differently 
than the simple majority of equally-weighted votes?  i *still* don't get it.

-- 

r b-j                  rbj at audioimagination.com

"Imagination is more important than knowledge."