[EM] 'Strategies'

[Alex Small]

> Is there a single ranked ballot system that is not subject to favorite
> burying?
>
> What systems, other than fptp, are immune, if any?

To the best of our knowledge, there is no pure ranked system that
doesn't encourage voters to sometimes insincerely rank somebody ahead of
our favorite.

Using more complicated ballots it's sort of possible, as Forest showed a
few months ago.  Two possible systems:

1)  Approval Runoff:  Approve any candidates that you wish to, and also
indicate a strict ranking of the candidates.  The approval votes need
not be consisten with your rankings (i.e. you could approve #2 on your
list without approving #1, your true favorite).  The method looks to see
which 2 candidates have the most approval votes, then it has a pairwise
contest between them.  The pairwise winner among those 2 is elected.

You might have an incentive to NOT approve your favorite.  Say your
least favorite is guaranteed to be one of the 2 most approved, and that
he can slaughter your favorite in a pairwise contest, but your #2 can
beat your least favorite pairwise.  You want a 2-3 contest, not a 1-3
contest.  However, you have no incentive for insincere RANKING, because
in the final pairwise contest you'll always want your favorite of the
finalists to win.


2)  Indicate a strict ranking of the candidates.  Also, approve or
disapprove PAIRS of candidates, from among the N(N-1)/2 possible
pairings of candidates.  The most approved pair go to the final round,
where the rankings are used to decide between them in a pairwise
contest.

You still have no disincentive for sincere rankings.  You also have no
disincentive for approving at least one pair that includes your
favorite.





Alex