[EM] Simmons' "solution" of voting system design puzzle is inadequate

Chris Benham chrisjbenham at optusnet.com.au
Sat Jan 20 14:00:40 PST 2007

Warren Smith wrote:

>Here is the current CRV web page about this problems and its (lack of) solution
>We are speaking about puzzle #5 at
> Puzzle #5: Voting systems immune to clones and avoiding favorite-betrayal
>Two desirable properties of a voting system - both of which Range Voting has - are "immunity to candidate-cloning" (ICC) and "avoiding favorite betrayal" (AFB).
>AFB: voters should never have strategic incentive to "betray" their favorite candidate by voting him below some other.
>ICC: political parties should be unable to usefully manipulate an election by running clones of their own, or of an opposed, candidate; voters here are assumed to vote honestly and to have only tiny preferences (which they may express in their votes, if they exist) among the clones.
By this definition Range fails "ICC" because voters can only express 
preferences among clones by not giving maximum possible score to all of 
them, thus making it
possible that if a narrow winner is replaced by a set of clones all the 
clones lose.

>Note: Many voting systems are known (beyond just variants of range voting) which satisfy AFB
Many?  There is MCA,  ER-Bucklin(Whole),  one or two Kevin Venzke 
methods and what else?

Chris Benham

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