[Election-Methods] A better IRV (was Re: Range Voting won't eliminate spoilers)

[Steve Eppley]

Greg doesn't need to twist my arm to get me to agree about spoiling in 
Range Voting, depending on the validity of the assumptions one must make 
(due to lack of empirical data using RV in high stakes public elections) 
about voters' strategizing. 

Also, as Greg implicitly pointed out where he wrote about some voters 
reducing Gore's rating when Nader runs, and about the basic strategy of 
rating candidates the range's upper or lower bound, it is wrong to claim 
Range Voting maximizes social utility.

However, IRV is worse at eliminating spoilers than some other methods.  
It also undermines candidates who take centrist compromise positions, by 
defeating them and making them appear unpopular.  As a consequence, we 
can expect IRV would continue the "two big polarized parties, each 
nominating one candidate per office" system (including its haphazard 
primary elections).

IRV might cause polarization even worse than what we already have, since 
the effective plurality rule campaign strategy of shifting toward the 
centrist swing voters after being nominated--which reduces polarization 
somewhat--would risk, under IRV, the late entry of an independent 
candidate competing at a position slightly closer to the party base.

IRV can be significantly improved by letting candidates withdraw from 
contention after the votes are cast.  At the end of election day, the 
votes would be published in a format that candidates (and others) can 
download.  Then the candidates would be given a few days to decide 
whether to withdraw.  They could use those days to calculate what the 
result would be with or without themselves (and/or some other 
candidates) in the voters' rankings, and to negotiate with supporters 
and with other candidates about who, if anyone, should withdraw.  The 
official winner would not be tallied until after the withdrawal period.

--Steve
-----------------
Greg @ Somerville for IRV wrote:
> I don't believe that Range Voting will eliminate even the kind of
> spoilers that IRV does away with. Consider two-candidate race between
> Bush and Gore in which 51 voters prefer Gore to Bush and 49 prefer
> Bush to Gore. Following the directions given on the RangeVoting.org
> website, voters should give a '10' to their favorite candidate and a
> '0' to their least favorite:
>
>   51 people rate Gore=10, Bush=0
>   49 people rate Bush=10, Gore=0
>   the result: Gore=510 > Bush=490 (Gore wins)
>
> Now we re-run the election with Nader in the race. When Nader enters,
> 5 people for whom Gore was their first choice switch to preferring
> Nader. Those 5 voters rate Nader a '10' and push Gore down to '5':
>
>   46 people rate Gore=10, Bush=0, Nader=0
>   49 people rate Bush=10, Gore=0, Nader=0
>   5 people rate Nader=10, Gore=5, Bush=0
>   result: Bush=490 > Gore=485 > Nader=50 (Bush wins)
>
> How could the 5 Nader voters suddenly have a different utility for
> Gore? In reality, the rating a voter will give to a candidate isn't
> some fixed objective measurement of their happiness with a candidate,
> but a rating relative to the options available. In short, everyone
> will naturally grades on a curve. To say that RV satisfies IIA is to
> ignore the reality that ratings will inevitably be relative.
>
> Thus, Nader would still be labeled a spoiler, because his entrance
> into a race causes some to rate Gore lower.
>
> Agree?
>
> Greg
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