[EM] Correction of false statements by Ossipoff & Schudy about range voting.

[Steve Eppley]

I partially agree with Chris Benham (see below).  Warren Smith's 
example, in which a voter has total knowledge of all other votes before 
casting her own vote, is implausible in the elections we're interested 
in reforming.

I don't know which methods Chris had in mind when he wrote "as fair and 
strategy-resistant as possible" but I'll take a moment here to defend 
the social utility of the best majoritarian preference order methods 
(such as MAM). 

Recall the example someone posted here several weeks ago intending to 
undermine the value of the majority rule criterion. Three friends, say 
X, Y and Z, are ordering a pizza. (It doesn't matter if they're friends; 
in the worst case they're not and they expect to never hear from each 
other again.)  Z is terribly allergic to mushrooms so he strongly 
prefers pepperoni, but a mushroom pizza is slightly preferred by X and 
Y.  There was no time to deliberate--which of course is implausible in 
the elections we're interested in reforming--so majority rule picks the 
mushroom pizza.

Or does it?  When X or Y proposes mushroom pizza, what if Z responds by 
proposing "pepperoni pizza plus the transfer of $1 from Z to X."  When Y 
hears this proposal, he thinks to himself that he'd prefer "pepperoni 
plus 50 cents" over mushroom, so Y proposes "pepperoni pizza plus a 
transfer of 50 cents from Z to Y."  Suppose X is even more indifferent 
between pepperoni and mushroom than Y is, and would prefer mushroom over 
pepperoni for just a dime.  X is clever, though, and bids 49 cents 
instead of a dime.  There was no deliberation; Z never admitted the 
allergy.  X and Z, a majority, both prefer X's final proposal over 
mushroom pizza. 

More precisely,
X's order of preference is:
    "pepperoni plus $1 to X"
    "pepperoni plus 49c to X"
    mushroom
    "pepperoni plus 50c to Y"  =  pepperoni

Y's order of preference is:
     "pepperoni plus 50c to Y"
     mushroom
     "pepperoni plus $1 to X"  =  "pepperoni plus 49c to X"  =  pepperoni

Z's order of preference is: 
      pepperoni
      "pepperoni plus 49c to X"
      "pepperoni plus 50c to Y"
      "pepperoni plus $1 to X"
      mushroom pizza

The only alternative for which no majority prefers some other 
alternative is "pepperoni plus 49c to X."  In the language some people 
use, it's the only alternative that's "unbeaten" pairwise.

Economists and political scientists call the transfer of 49 cents from Z 
to X a "side payment."  Side payments are a specific case of the more 
general solution: proposals that bundle alternatives.  That can also be 
called vote trading. in the case where the bundling is accomplished by 
trading votes on otherwise unlinked issues. 

A preference order on bundles is one way an individual can express her 
utilities, and is much more meaningful about her utilities--potentially 
allowing interpersonal comparisons of utilities--than the unitless votes 
expressed in Range Voting.  For example, the three friends learned that 
the utility difference for Y between mushroom pizza and pepperoni pizza 
is approximately 50 cents, since Y chose not to bid below the 49 cents 
that X bid.

Candidates wanting to win try to figure out a winning platform.  Given a 
good preference order method, the winning platform will be some 
"centrist" compromises, and competition will not be deterred.  
Candidates are creative; they can bundle together a platform of policies 
on unrelated issues, including side payments from some voters to others, 
and they'd have an incentive to try to figure out a platform (like X's 
proposal of Z's pizza plus 49 cents from Z to X) that minimizes the 
possibility that another candidate will find some platform preferred by 
a majority.  That competition should tend to drive them toward platforms 
that score well for social utility.

If the good preference order method of the previous paragraph also 
permits candidates to withdraw after the votes are cast, there will be 
little incentive for voters to strategically misrepresent their sincere 
orders of preference.  Warren Schudy neglected to consider such 
Condorcetian methods in his paper about Approval. (He also neglected to 
consider that the voting method--and candidates' beliefs about voter 
behavior, given the voting method--affects candidates' decisions on 
whether to run, and on what platforms, and hence will affect the voters' 
preferences.  Many people in this maillist make the same 
mistake--treating the set of alternatives and the voters' preferences as 
constant when comparing wildly different voting methods--and it's a huge 
mistake.)

If the good preference order method also permits each voter on election 
day to begin by selecting a ranking published before election day and 
modifying it if desired--perhaps by drag & drop; see the feature in the 
new NetFlix user interface for an example--before submitting it as her 
vote, then we won't have to worry, when there are many candidates, about 
the possibility that voters will fail to rank a compromise candidate 
needed to defeat a "greater evil."  This could also sharply reduce the 
amount of campaign money needed for good candidates to win, since it 
doesn't cost much for a candidate to contact the people publishing 
rankings (presumably other candidates, and some NGOs).  For more 
information on Voting by Selecting a Published Ranking see my message 
posted in April 2006.

Some people here believe Approval is best, or like Mike Ossipoff seem 
willing to settle for Approval.  One of Mike's arguments is that it 
would be good for society to minimize the number of voters who 
(strongly) disapprove of the winner.  He seems to define disapproval as 
some strong negative emotional response rather than as a preference for 
leaving the office vacant (which I believe--based on a conversation with 
Matt Jackson, professor of economics and political science at 
Caltech--is the standard definition in the rational choice model).  
Those negative emotions may or may not be something society should 
minimize.  Even if they are, it does not follow that voting methods that 
ask voters to express approval or disapproval will do this as well as 
voting methods that ask voters only to rank the candidates in order of 
preference.  I believe the best way to minimize those negative emotions 
is with a voting method that encourages candidates to compete to be the 
best compromise and doesn't deter candidates who don't care about 
winning from taking "uncompromising" positions.  It would enable voters 
to rank the less corrupt compromise candidates over the more corrupt 
compromise candidates, since their platforms will be similar.  Election 
day is for making a collective decision, involving compromising as far 
as is necessary to defeat what's worse; the rest of the time is 
available for deliberating over what's really best.

Regards,
Steve Eppley
---------------------------------
Chris Benham wrote:
>
>
> Warren Smith wrote:
>>> Warren Schudy in a July 2007 draft paper:
>>> "Range voting is a generalisation of approval voting where you can give
>>> each candidate any score
>>> between 0 and 1. Optimal strategies never vote anything other than 0 or
>>> 1, so range voting
>>> complicates ballots and confuses voters for little or no gain."
>>>
>>> Ossipoff: Warren Schude's statement was correct
>>>     
>> --CORRECTION: optimal strategies can vote other than 0 and 1, and
>> voting 0 or 1 can be suboptimal.
>>
>> Examples include
>> http://rangevoting.org/RVstrat1.html
>> http://rangevoting.org/PuzzlePage.html#prob19
>>
>> Also, just in the following incredibly trivial total knowledge example
>> TOTAL FROM OTHER VOTERS:  A=85.4  B=85.5
>> YOUR VOTE:    A=?  B=?
>> the vote A=1 B=0 is equally as optimal as A=0.9 B=0.1.
>> This also falsifies the statement "Optimal strategies never vote anything other than 0 or 1".
>>   
>
> I don't have a "password", so I can't access the given puzzle 
> solution.  Warren Schudy's "never" I suppose meant "never in a remotely
> plausible public political election scenario".  I knew there was the 
> odd exception in elections with very few voters and/or the voter has
> much more precise information than s/he could ever plausibly have in a 
> public election.
>
> Regarding "social utility", I'm of the school that says that to the 
> extent that it is a real and wonderful thing it will look after itself 
> if we do
> our best to ensure that the election method is as fair and 
> strategy-resistant as possible.
>
> Chris Benham
>
>
>
>
>
>
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