[Election-Methods] RELEASE: Instant Runoff Voting (Chris Benham)

[Juho]

On Jun 24, 2008, at 3:10 , Abd ul-Rahman Lomax wrote:

>>  Or if A and B are the strongest candidates then maybe
>> strategically A=10, B=0, C=0.
>
>>  In Approval the voter might vote A=1,
>> B=0, C=0. Or if B and C are the strongest candidates then maybe A=1,
>> B=1, C=0.
>
> If it were me, I might be buying tickets out of the country. That  
> is *really* bad. *Sincere normalized rating, unmodified by election  
> probabilities, is almost zero.*
>
> Voters with utilities like this, if they believe A doesn't have a  
> prayer, tend to not vote.

Note that the utilities of B and C were 123 and 99. I didn't anchor  
the scale in any way but numbers around 100 could still be "above  
average politician".

>> The sincere opinions/utilities A=543, B=123, C=99 were valid in all
>> the cases but typical voter behaviour in Range and Approval was to
>> normalize the vote and maybe to vote strategically depending on who
>> the strongest candidates are. The ratings given to the candidates
>> varied although the opinions/utilities stayed the same all the time.
>>
>> This changing behaviour may sometimes lead to one of the candidates
>> being a spoiler.
>
> Plurality, if voters vote sincerely, guarantees the spoiler effect.  
> It's part of the method. Range allows something different, but  
> nobody coerces voters. *Voters* can decide to act in ways that  
> mimic the spoiler effect, but it's not intrinsic to the method, and  
> if voters vote with any reasonable understanding at all, there is  
> no spoiler effect with any significant frequency with Range or  
> Approval.
>
> How many voters in 2000 would not have known that Bush and Gore  
> were the frontrunners? The decision in Approval is quite simple: if  
> you want to influence the election, vote for one of the  
> frontrunners, period. Indeed, it gets tricky when there are three  
> frontrunners, but that is vanishingly rare in the U.S.

I think three frontrunners is not a very distant scenario. I also  
think spoilers are quite possible in Range and Approval. Some spoiler  
scenarios were already mentioned in this thread. You also already  
replied to Chris Benham on the McCain-Obama-Clinton example in  
another mail (and therefore I'll try to be brief here).

The Democrats would do wisely if they would not nominate the second  
candidate as a "spoiler" even if the campaign would not be a mud  
slinging campaign. And Clinton would do wisely (from the D party  
point of view) if she would not accept a nomination by some other  
party close to Democrats. And in a close election any candidate close  
to Democrats would probably do wisely (from D point of view) if he/ 
she didn't join the race (since Republicans are more likely to rate  
all Democrat resembling candidates at 0 than Democrat like voters  
would rate all Democrat like candidates at max points).

Juho





		
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