[Foundation-l] Board vote, need a bit of help

[Gregory Maxwell]

On Sun, Jun 8, 2008 at 8:17 AM, Anthony <wikimail at inbox.org> wrote:
>> You could also leave Fidel Castro unranked but that would have exactly
>> the same effect on the election.
>
> Would it?  Due to the failure of later-no-harm, isn't it possible that
> ranking Satan over Castro might actually cause Batman to lose and
> Satan to win?

Leaving candidates *unranked* is the same as ranking them with the lowest rank.

However, ranking Satan over Castro might help Satan win vs Batman but
only if Satan and Batman are among the set of winners, see below.

>> Schulze method does not not have the "Later-no-harm criterion", so
>> your less preferred choices *can* influence results related to your
>> higher preferred choices.  But, unlike approval or borda Schulze's
>> failure to meet later-no-harm doesn't translate into an obvious usable
>> strategy in the general case.
>>
> http://en.wikipedia.org/wiki/Later-no-harm_criterion gives a much
> needed example of this.
>
> I think I can derive at least one general strategy for this situation,
> and it seems to resolve my problem with the condercet criterion
> promoting compromise candidates.  The strategy is, if there are
> multiple candidates that are *unacceptable*, you shouldn't rank any of
> them.

As above, Leaving them unranked is absolutely equal to giving them all
the next lowest rank.

My understanding is that Schulze fails later no harm only in a very
limited way: The winner is guaranteed to be a member of the Schwartz
set.  The Schwartz set is the smallest set who's members are all
unbeaten by non-members.  It wouldn't be unreasonable to call all
members of the Schwartz set ties.

Your ranking of Satan over Castro can't cause Satan to be unbeaten by
Batman.   But if all three of these were members of the Schwartz set
then your preference of Batman > Satan > Castro might end up helping
Satan win over Batman (and Castro) by influencing the tie-breaking.

But if your hated candidate is already in a form of a tie with your
favored candidate.. you're already in a pretty bad situation. :)

Incidentally I think the only way to remove this risk entirely is not
to vote at all. Which, I guess, is why Schulze fails the Participation
criterion (http://en.wikipedia.org/wiki/Participation_criterion).

> Another way of looking at this is that you really are indifferent
> between all unacceptable candidates.  You may hate Castro more than
> Satan, but either way if one of them wins and the board ratifies the
> decision you should leave the project and work actively against it.
> And from the other side of the coin, if a voter doesn't think either
> of two candidates are acceptable, their vote shouldn't count anyway.

Sounds like am argument for IRV. ;)

Or really, under your line of thinking, plurality with voters who are
always honest about their preferences would probably be ideal.  Dunno
where you find voters who are always honest. ;)