[EM] Sequential elimination method that turns out to be a generalization of fpA-fpC

[Kristofer Munsterhjelm]

On 4/23/23 21:45, Filip Ejlak wrote:
> I take that back - even if it always chooses an uncovered candidate, the 
> method is not totally independent of covered alternatives.
> In this 4-candidate cycle example:
> 
> 8: A>B>C>D
> 9: B>D>A>C
> 12: C>D>A>B
> 
> Landau set is {A,B,D} as B covers C (and gets their 1st preferences 
> added to the score), but C owns all their 1st preferences at the expense 
> of D. Eliminating C in the first round doesn't happen because D would 
> gain too much at the expense of B. A gets eliminated instead, and 
> eventually B wins.
> 
> If Landau//[This Method] was used instead, D would be the winner.

That's not surprising -- under mild assumptions, you can't have 
monotonicity and independence of covered candidates.

I haven't quite gathered how the elimination process works. Could you 
give an example election, e.g. the 4-candidate cycle example above?

-km