[EM] Approval & disapproval voting

[Kristofer Munsterhjelm]

On 2023-08-27 15:55, Colin Champion wrote:
> On second thoughts, would this not lead to tactical voting? I imagine 
> that a voter who both approved and disapproved would have more influence 
> than one who only approved or only disapproved.

Yes; for every Range-style single-winner voting method, the optimal 
strategy is to give everybody above some threshold rank the highest 
possible score, and everybody below it the lowest possible score.

(This doesn't necessarily hold for a proportional multiwinner method, 
though, even if it reduces to Range in the single-winner case.)

-km