[EM] Is there a criterion for identical voters casting identical ballots?

[Juho]

On Dec 18, 2006, at 8:31 , Dave Ketchum wrote:

> How did we get here?
>
> You talk of a method in which ONE voter can say BOTH A>B AND B>A.
>
Yes, either in the sense that both lose to each others or in the  
sense that both win each others.

> Assuming such a method could claim useful value to justify the  
> headaches of implementing it and making it understood, I have seen  
> nothing to suggest Condorcet might have such an ability.

See e.g. http://wiki.electorama.com/wiki/Tied_at_the_top_rule.

The reason I discussed this possibility is the fact that it frees the  
voter from creating an artificial loop and deciding in which  
direction it should run.

>     In Condorcet the sum of all the ballots in an election can be a  
> combination of some voters voting each preference in a way to,  
> collectively, create a cycle - a problem to solve but not a feature  
> to brag about.
>
Agreed. The tied at top/bottom rules are tricks that may relieve this  
a bit. (Their other characteristics would need to be discussed more  
to tell if they are good or bad in general.)

> You also use the word "loops" in a manner I do not understand.
>
I don't know how but I think I referred to artificial intentionally  
generated circular preferences every time.

Juho Laatu


> DWK
>
> On Sun, 17 Dec 2006 21:40:02 +0200 Juho wrote:
>> I thought mostly use scenarios where the favourite candidate is  
>> not  involved in the cycles and the voters know very little about  
>> the  anticipated results. Another example in this direction would  
>> be  situation where there are n parties that each have 3  
>> candidates.  Voters would then vote so that they first put their  
>> own candidates in  the front (in some order (ffs)) and then the  
>> other parties in the  order of preference but arranging the  
>> individual candidates within  the parties so that they will form  
>> cycles (between each others within  the parties).
>> Note btw that this failure of FAVS (as Warren Smith named it) is  
>> not  really related to the calculation process of the Condorcet  
>> methods  but to the ballot style. In the typical ballots voters  
>> give the  candidates a linear order, which prevents them giving  
>> cyclic  preferences. If they were able to give cyclic preferences  
>> then all  voters could vote the same way.
>> In principle (to be general) one could allow voters to fill a  
>> matrix  instead of giving a linear order. This would make it  
>> possible to use  also cycles and all kind of partial orderings. A  
>> related topic is the  tied at the top and tied at the bottom rules  
>> where the top candidates  may all win each others (or at the  
>> bottom lose to each others).  Support of the tied at bottom  
>> feature would make it unnecessary to  vote loops since this way  
>> all unwanted candidates would lose to each  others. This feature  
>> could also be added in the "matrix preference  votes" to eliminate  
>> some strategic loop considerations.
>> Also the linear order based ballots could have explicit ways to  
>> mark  "both lose" and "both win" etc. (instead of the default  
>> rules "tied  at top",...), but of course this makes voting more  
>> complex to the  voters (just like allowing full matrix preference  
>> votes would do).  Using "+" and "-" a ballot might look e.g. a 
>> +b>c=d>e-f>g-h-i.
>> Just for your consideration. Different ballot styles may have an   
>> impact on strategies too.
>> Juho Laatu
>> On Dec 15, 2006, at 15:02 , Dave Ketchum wrote:
>>> How did we get here?
>>>
>>> I assume no ties to simplify the discussion - not to change the  
>>> rules.
>>>
>>> If there is a cycle, such as X>A>Y>X, A backers have no control  
>>> as  to X>A, but they can influence whether there is also a Y>X  
>>> to  create a cycle.
>>>
>>> Else, assuming more voters back X than A, A loses and it matters   
>>> not what ordering A backers choose for others.
>>>
>>> If there is no such X, A wins and it matters not how A backers  
>>> sort  those losing to A.
>>>
>>> LOOKING CLOSER - If A backers want to be neutral as to B/C/D,  
>>> they  can simply vote for A as they would in Plurality.
>>>
>>> On Fri, 15 Dec 2006 00:01:04 +0200 Juho wrote:
>>>
>>>> Here is one very basic case where a group of voters has  
>>>> identical   preferences but they benefit of casting three  
>>>> different kind of  ballots.
>>>> In a Condorcet method there is an interest to create a loop to   
>>>> your  opponents. In its simplest form there are four  
>>>> candidates.  One of the  candidates is our favourite and the  
>>>> others we want to  beat. The  others may or may not be from one  
>>>> party (this  influences the  probability of being able to  
>>>> generate a cycle at  least if there are  more than 4  
>>>> candidates). Let's anyway assume  that all the candidates  will  
>>>> get about the same number of votes.  Also in a zero info   
>>>> situation this may be a good voting strategy.  The A supporters  
>>>> vote  according to three patterns as follows.
>>>> A>B>C>D
>>>> A>C>D>B
>>>> A>D>B>C
>>>> If all candidates have same number of first place supporters  
>>>> (and   other preferences are mixed) and B, C and D supporters  
>>>> don't try  to  create loops, A wins.
>>>> Juho Laatu
> -- 
>  davek at clarityconnect.com    people.clarityconnect.com/webpages3/davek
>  Dave Ketchum   108 Halstead Ave, Owego, NY  13827-1708   607-687-5026
>            Do to no one what you would not want done to you.
>                  If you want peace, work for justice.
>
>

Send instant messages to your online friends http://uk.messenger.yahoo.com