[EM] IRV3/AV3

[Andy Jennings]

>
> But there are ways in which I think IRV encourages spoiler scenarios.
>>  Consider a city that has a slight Democratic bias.  That is, Democrats win
>> by 8-10% most of the time.
>>
>> Step 1) A "Progressive" party starts up that thinks the Democrats have
>> gotten complacent and are not ambitious enough.  This resonates with people
>> but they're scared to vote for third parties.
>>
>> Step 2) IRV supporters tell everyone it's safe to rank your favorite
>> first.  Some people rank the Progressives first, and nothing bad happens!
>>  People gain confidence in IRV and ranking your favorite first.  More
>> people start ranking the Progressive first.
>>
>> Step 3) Eventually the Progressive party overtakes one of the top two
>> parties to make it into the final round.  The party overtaken is almost
>> certainly the Democrats (because the Progressive party wasn't taking any
>> votes from the Republicans).  So who did the Democrats put for their second
>> choice?  If even a small fraction of the Democrats put the Republican
>> second, then the Republican will win, and we have had a successful spoiler
>> scenario.  (Yes the Progressive was the spoiler even though they made it to
>> the final round.)  Voting for the Progressive caused the Republican to win.
>>  Progressives should've put the Democrat first.
>>
>> Step 4) Progressives and Democrats get very angry at each other and
>> everyone is angry at the Republicans.  A majority is angry at IRV.
>>
>
> Or what if the Dems get smart instead of angry and decide to work things
> thru with the Progs?  It's not IRV, it's the fact that the Dems weren't
> progressive enuf so as to make the Progs gain popularity and risk spoiling
> things for the Dems.  This is the same dynamic that exists today for FPTP.
>

Yes, ideally that would happen.

But as you say, the same dynamic exists today with FPTP.  And what has it
led to?  Total marginalization of third parties.  Everyone knows you only
should vote for the top two parties, otherwise you're wasting your vote.
 Two-party domination.  I'm not happy with that, and it seems to me that
IRV is prone to the same equilibrium.

On the other hand, the Tea Party movement has shown that the major parties
are movable, to some degree.  So I see what you're saying.  Maybe they
would be more movable with IRV.  But now you're talking about the whole
electoral/political landscape compensating for faults in IRV.  Wouldn't it
be better just to pick a better voting system to base the system on in the
first place?

Also, you made a remark at one point that the United States political
landscape is naturally highly-polarized into two parties so we should try
to work within that landscape.  But I believe Duverger's Law (
http://en.wikipedia.org/wiki/Duverger's_law).  That is, the US has
two-party domination _because_ we use plurality voting.  I believe the
political landscape would quickly re-configure itself if we had a better
voting system.

~ Andy
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