[EM] Historical perspective about FairVote organization
ElectionMethods at VoteFair.org
Sun Mar 17 10:32:08 PDT 2013
On 3/15/2013 2:12 AM, Kristofer Munsterhjelm wrote:
> On 03/14/2013 06:45 PM, robert bristow-johnson wrote:
>> IRV will prevent a true spoiler (that is a candidate
>> with no viable chance of winning, but whose presence in the race changes
>> who the winner is) from spoiling the election, but if the "spoiler" and
>> the two leaders are all roughly equal going into the election, IRV can
>> fail and *has* failed (and Burlington 2009 is that example).
> If you think about it, even Plurality is immune to spoilers... if the
> spoilers are small enough. More specifically, if the "spoilers" have
> less support in total than the difference in support between party
> number one and two, Plurality is immune to them.
> So instead of saying method X resists spoilers and Y doesn't, it seems
> better to say that X resists larger spoilers than Y. And that raises the
> question of how much spoiler-resistance you need. Plurality's result is
> independent of very small spoilers. IRV's is of somewhat larger
> spoilers, and Condorcet larger still (through mutual majority or
> independence of Smith-dominated alternatives, depending on the method).
This is a good example of the need to _quantify_ the failure rate for
each election method for each "fairness" criteria.
Just a yes-or-no checkmark -- which is the approach in the comparison
table in the Wikipedia "Voting systems" article -- is not sufficient for
a full comparison.
> It's like reinforcing a bridge that would collapse when a cat walks
> across it, so that it no longer does so, but it still collapses when a
> person walks across it. Cat resistance is not enough :-)
Great analogy. We need to start assessing _how_ _resistant_ each method
is to each "fairness" criteria.
> It would be really useful to know what level of resistance is enough,
> but that data is going to be hard to gather.[...]
Indeed, that is difficult.
> And beyond that we have even harder questions of how much resistance
> is needed to get a democratic system that works well. It seems
> reasonable to me that advanced Condorcet will do, but praxeology
> can only go so far. If only we had actual experimental data!
My VoteFair site collects lots of data. I have used it to verify that
VoteFair ranking accomplishes what it was designed to do. Not only has
such testing been useful for refining the code for the single-winner
portion (VoteFair popularity ranking, which is equivalent to the
Condorcet-Kemeny method), but such testing has revealed that VoteFair
representation ranking (which can be thought of as a two-seats-at-a-time
PR method) also works as intended.
As for praxeology ("the study of human conduct"), I also watch to see
how people try to vote strategically. The attempts are interesting, but
I agree that using better ballots and better vote-counting methods in
real situation -- using real data -- is essential for making real progress.
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