[EM] ER-Bucklin fails monotonicity

[Chris Benham]

Kevin,
That is interesting, but you should have specified ER-Bucklin(Whole).  
ER-Bucklin(Fractional) works fine in your example.
You wrote:

>Consider these ballots:
>
>40 A>B>D
>35 D>B
>25 C>D
>
>B wins, with 75 votes in the second round.
>
>Now let's raise B on some ballots:
>
>40 A=B>D
>35 D>B
>25 C>D
>
>Now candidate D wins, with 100 votes in the second round.
>
The "fractional" version would give the same result as if  half  the  
A=B>D voters had voted A>B>D and the other half  B>A>D. In the first 
round, the A=B>D ballots each give half 
a vote to A and B and in the second round they each give another half a 
vote to A and B (and nothing to D) so B wins as before with 75 votes in 
the second round.


Chris Benham