the No Spoiling criterion

[Steve Eppley]

Bruce A wrote:
>Steve E wrote:
>>    If candidate X would be elected when Y is not a candidate, 
>>    then X or Y will be elected if Y is a candidate (assuming 
>>    the voters don't alter their relative orderings of the 
>>    non-Y candidates).
>
>Basically, this is what Arrow's theorem says is impossible for a 
>rank-order voting method to satisfy (without a "dictator" or other 
>such contrivance).

Like the LOE criteria we've developed, a rigorous No Spoiler
criterion which can be met by at least one voting method would 
have to have some qualifications.  As with the LOE criteria, 
the qualifications wouldn't necessarily detract much from its
importance as a criterion. 

---Steve     (Steve Eppley    seppley at alumni.caltech.edu)