[EM] Comments on some rank methods

[Kristofer Munsterhjelm]

On 04/10/2012 10:20 PM, MIKE OSSIPOFF wrote:
>
> Kristofer:
>
> You wrote:
>
>> On 04/09/2012 11:31 PM, MIKE OSSIPOFF wrote:
>>>  I've said seemingly contradictory things about IRV. It's particularly
>>>  flagrant FBC failure makes it entirely inadequate for
>>>  public political elections, more so than Condorcet, which, too, is
>>>  inadequate due to FBC failure.
>>
>> You keep saying anything without FBC is automatically a no-go. How do
>> you know that?
>
> [endquote]
>
> It is a country-specific observation, regarding the electorate of the U.S., where I
> reside. I don't know that about any other country, though there is evidence for it in various
> countries where people are used to Plurality voting.
>
> Yes this is "anecdotal", but I've personally observed favorite-burial in Condorcet voting.
>
> A safe and prudent rule is "Never underestimate the voter's inclination for resigned over-compromising
> give-away, if there's any chance that it could help a compromise against someone worse."

Yet that isn't absolute. Again, consider Burlington. The Burlington 
voters, thinking they could now vote as they wished, ranked the 
candidates in a manner suggesting a relatively close race between the 
three major candidates. They didn't discover this was a bad idea until 
after the election, but a Condorcet method would have given them the 
right winner.

Given that observation, would not Condorcet acting properly have 
encouraged the voters to vote in a non-compromising manner in later 
elections? Although there's no hard evidence, it seems reasonable.

Or do you prefer the voting method to give an ironclad assertion that 
there won't ever be a favorite betrayal problem, so you can be *sure*? I 
can see that. Since I'm in a country where favorite betrayal isn't a 
problem, I don't really feel the need to be absolutely sure. That, and I 
like Condorcet :-)

>>>  And I also said that IRV would be a fine method, were it not for the
>>>  public's inclination towards resigned, cowed overcompromise,
>>>  and their very sad and disastrous lowering of standards for
>>>  acceptability. "Vote for the least bad of the corrupt candidates,
>>>  because they're the
>>>  winnable ones".

>> I disagree. Look at Burlington with its center squeeze again. The
>> Burlington voters didn't strategize (much or effectively). Yet instead
>> of picking the candidate closest to the median voter, IRV threw that one
>> away because it didn't have enough first-place votes and picked the
>> largest wing instead.
>
> [endquote]
>
> Never choose IRV as a way to attain the voter median. For that, I recommend ICT
> for public political elections. Condorcet(wv), maybe Beatpath, would be ok for organizations.

If it fails to acquire the voter median even when voters aren't 
overcompromising, how can IRV be a fine method?

> You continued:
>
>> How about this zero-info: Rank all the acceptables in alphabetical
>> order. Rank the unacceptables in random order after the acceptables.
>
> [of course, in that situation, there'd be no need to rank the
> unacceptables, unless the rules require ranking everyone]

Some IRV implementations require that the voters rank everyone, so the 
strategy might have to take that into account. If the voters don't have 
to rank everyone, then I agree with you. Since IRV passes both LNHarm 
and LNHelp, the only reason you'd rank unacceptables would be if you had 
some preference between them.

> ...if the rules require ranking everyone.  You'd be preferentially helping the unacceptables
> least likely to benefit from that help.
>
> But, by the time your vote gets to the unacceptables, the acceptables must have all been
> eliminated. So, if you're going to rank the unacceptables, wouldn't it be best to rank
> them in order of preference (in reverse order of unacceptability)?
>
> There's a good case for not bothering to rank them, if the all-important thing is
> keeping an unacceptable from winning. But, by ranking them, you could at least try
> to help the least bad of them against the worst of them.

That's a good point.