[EM] Real IRV Election, Disputable Result

Dave Ketchum davek at clarityconnect.com
Mon Mar 13 22:39:57 PST 2006

BTW - it took more than a day for EM to pass this on to where I could see it.

Delighted to have a Rep. take an interest - too much of the time all that 
happens here is debate as to theory.

On Sun, 12 Mar 2006 11:28:48 -0500 radio deli wrote:

> Dear Jan,
> I saw your post on the Elections Methods List.  As a Vermont legislator, 
> we may have to decide the issue of IRV on a statewide basis.  To be 
> honest, I'm not very enthusiastic about IRV.  I would prefer to support 
> the candidate (not plural) of my choice, and if a runoff must occur 
> between candidates I didn't support, then make a new decision based on 
> the contest at hand. 

For the moment I will talk only of "ranked choice", which includes both 
IRV and Condorcet.  As you enter the debate, please stick with ranked 
choice, for which the ballots are identical for the two methods.  While 
they take a different approach to counting, they usually agree as to 
winner.  Let us debate whether ranked choice is worth doing before you 
choose between the methods.


Also please ignore the debate on EM about the mayor election - there has 
been too much misunderstanding in that debate.

You seem to be, like most of us, used to Plurality voting.  It is good 
enough when there are only two popular candidates.

If ranked choice was made available you should still be able to vote as if 
via Plurality, and runoffs, with their expense, could still be available.

Among runoff's many problems, can happen that the candidates you consider 
acceptable all got eliminated from the runoff.

Back to Plurality.  Can happen there are two acceptable candidates, and 
one lemon.  Ranked choice lets you rank the good ones ahead of the lemon, 
expressing your actual thoughts more completely.

> What are the problems you see with IRV?  Could you explain them in a way 
> that people without a statistics degree (like me) could comprehend?  I 
> hope you have a chance to respond---you seem quite knowledgeable on the 
> topic!

Mostly ranked choice should work well.  Voters rank as many of the best 
candidates as they consider worth bothering with.  The counting routines 
ignore the least liked candidates and choose winner among the most liked.

There are possible problems - which need attending to, but do not happen 
as often as the debates would suggest.

Conspiring to gimmick the results:  Assuming one knows what the voters 
would normally vote, plotters can gimmick their votes to affect the 
result.  BUT:
      Plotters must know what would happen normally.
      Plotters depend on others NOT finding out and plotting to destroy 
their efforts.

IRV can fail to properly pick winner.  Given B is more than twice as well 
liked as A, normal voting for A, B, X, and Y can confuse the counting such 
that A wins AND THOSE VOTERS can realize that B had the popularity to 
deserve winning.

Condorcet can be uncertain as to winner - what is called a cycle, such as 
A>B, B>C, and C>A.  Means multiple groups of voters had conflicting 
desires.  I claim result is acceptable providing care is used in he 
counting, for all the candidates involved had to be near to equally liked 
to create the cycle.

Many districts are multiple precincts for which results must be summed 
and, anyway, district results need publishing:
      Plurality - a 1-dimensional array.
      Condorcet - a 2-dimensional array.
      IRV - something more complex.

> Best Regards,
> Rep. Jim Condon
> Colchester, VT          

  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.

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