[EM] Self/peer election methods

[Kristofer Munsterhjelm]

Let's say a group of people are voting on each other's suitability or on 
their works. Then unless the method is modified to take this into 
account, each candidate-voter has an incentive to rank himself highly 
and everybody else low.

In Plurality voting, the common way to fix this is to bar a voter from 
voting for himself. But that's not sufficient in other methods. Consider 
Range, for instance. If A is barred from rating himself, but knows that 
his most serious competitor is B, then he's incentivized to rate B zero.

But I think I've found a more general rule, which is simply this: when 
the method determines whether A is higher ranked than B, it should 
automatically disregard the ballots of both A and B.

For instance, in the Range example above, let A~>B if A's score (without 
either A or B's ballots being counted) is greater than B's. Then elect 
the candidate who beats everybody else by the ~> relation.

For Condorcet, this simply means that the magnitude A>B should not 
include either A or B's preference; in practice that means that both A>B 
and B>A will be down one (since given the opportunity, A would be likely 
to vote himself top, as would B vote himself top).

More sophisticated strategy could still work, and ~> could even turn out 
to be intransitive. In the Range example, perhaps one would need a 
tiebreaker beyond what ordinary Range would need. But it should limit 
the most obvious strategy.

-km