Random Ballot Tiebreaker

[Blake Cretney]

--

On Wed, 26 Aug 1998 13:22:07   Markus Schulze wrote:
>Dear participants,
>
>Blake wrote (25 Aug 1998):
>> This method might work, maybe it's what Tideman intended:
>> 1.  Pick a random ballot and use its rankings, consider
>>     ties as unsorted with regard to each other.
>> 2.  Continue picking ballots.  When you find one that
>>     orders previously unsorted candidates, use the ballot
>>     to sort them.  Do not change the order of the already
>>     sorted.
>> 3.  If you go through all ballots, and some candidates
>>     are still not sorted, order them randomly.
>
>To my opinion, your method is _unnecessarily_ random.
>I would propose the following random tiebreaker:
>
>   If an algorithm doesn't lead to a unique winner
>   but to a set of potential winners, then pick a random
>   ballot. That potential winner, who got the best
>   preference of this random ballot, is elected. If more
>   than one potential winner got the best preference of this
>   random ballot, then the whole algorithm is restarted
>   with the top ranked potential winners of this random
>   ballot.
>
>To my opinion, randomness should be used _only_ in those
>cases in which no other justifiable reduction of the set
>of potential winners can be made. The reason: I doubt,
>whether a randomly chosen winner will have the authority
>that he needs to do his work.
>

I wonder if you're algorithm will really give results that are less random.  I'll give you an example of what I mean.

A > B 60
B > C 60
C > A 60

My random ballot method will directly select one of these candidates.  Your method will sometimes do this, but sometimes eliminate one of the candidates and rerun the algorithm instead.  In abstract, it seems less random to do it this way; in the above example it clearly isn't less random.  Can you give an example where it would be?


-----== Sent via Deja News, The Discussion Network ==-----
http://www.dejanews.com/  Easy access to 50,000+ discussion forums