[Election-Methods] IRV ballot is at least as fair as FPTP ballot

[Kevin Venzke]

Hi Kathy,

--- Kathy Dopp <kathy.dopp at gmail.com> a écrit :
> > Date: Wed, 26 Dec 2007 19:33:27 +0100 (CET)
> > From: Kevin Venzke <stepjak at yahoo.fr>
> > Subject: [Election-Methods] RE : Re: IRV ballot is at least as fair as
> >         FPTP    ballot
> > > >  Yes some voters have second-choice considered but they are all
> still
> > > > treated equally.
> 
> So, you "define" equal as your ballot's first and second choices
> count, but someone else's first and second choices do not.

It is very difficult to define what it means for a preference to "count."
You can certainly define what "count" means for IRV, but it's not clear
that you will be able to use the same definition with other election
methods.

In the case of IRV, if my second choice is "counted," then this likely
means my vote was being wasted while it was on my first choice. Does my
vote "count" if the vote is hurting me?

> > But it does this according to what it believes each voter wants. If
> your
> 
> Well I don't want some voters' second choices given consideration but
> not all voters' second choices given consideration.  Will it take what
> I believe into consideration?  No.

I don't know any methods that can take into consideration what voters
believe the method should be.

> > first preference wins the election, then you don't want your second
> > preference to be counted. If your first preference is a very weak
> > candidate, then you want him to be eliminated so that your second
> > preference can be counted.
> 
> One problem is that my second choice candidate may be eliminated in
> the first round and my first choice candidate not have success either
> - despite the fact that my second choice candidate is the most popular
> among all voters.

Absolutely. This is why I do not think IRV is a good method. But in this
respect it is not any worse than first preference plurality. Isn't that the
method used where you live?

> I created a list of the 12 voters and their choices in a spreadsheet.
> I suggest you do a little experimenting on your own because I do not
> have time to do the analysis for you  because I am too busy to spend
> my time disabusing you of a fiction you hold. I am working on other
> more critical matters.  Please do the analyses yourself with a
> spreadsheet so you can see how trivially easy it is to make IRV put
> the wrong candidate, not supported by most voters into office.

This behavior of IRV is not news, not even really disputed that it's
unfortunate. This mailing list goes back over 10 years. Here is a link to
the archives. Try to see how easy it is to find criticism of IRV:
http://lists.electorama.com/pipermail/election-methods-electorama.com/

>From your response to Dave Ketchum:

> I have to say that I like the Condorcet method better than IRV because
> it does seem to treat the ballots equally - as long as voters vote for
> the same number of candidates - but I still don't like it as much as a
> system that weights a voter's first choice more than a voter's second
> choice, and so forth.
.... 
> I prefer a weighted method where I can give my first choice a certain
> weight more than my second choice, but all the candidates I vote for
> are tabulated - so there are no "elimination rounds".

The problem with weighting the rankings and just adding them up, is that it
creates the same kind of undesirable strategic incentives that IRV can
have. For example, if your preference order is Nader>Gore, but you know
that Nader can't win the election, then under a weighted rankings method
you should actually vote Gore>Nader so that Gore can receive the most
support from you possible.

It's often called "favorite betrayal incentive" or "compromise incentive"
when a method gives you good reason to use this kind of strategy.

Kevin Venzke


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