[EM] SARC definition improvement

[Markus Schulze]

Dear Mike,

you wrote (24 Aug 2000):
> Example:
>
> Your sincere ranking is ABC
>
> 100 voters: ABC
> 99 voters: BAC
>
> Without you, A wins.
>
> Then you show lup, and, believing that B needs your vote against C,
> you vote BAC. Now B wins. You've defeated your favorite by voting
> an undefeated strategy.

How do you interpret this example showing Borda violates SARC?
Do you say "It is a problem that this additional voter is punished
for showing up and using an offensive strategy. An election method
should guarantee that a given voter never worsens the result of
the elections (due to his sincere preferences) by showing up
independently on whether this voter votes sincerely or uses a
defensive strategy or uses an offensive strategy."? Or do you
say "It is not a problem that this additional voter is punished
for showing up and using an offensive strategy. The fact that a
given voter can worsen the result of the elections (due to his
sincere preferences) by showing up and using an offensive strategy
deters this voter from using an offensive strategy."?

Markus Schulze
schulze at sol.physik.tu-berlin.de
schulze at math.tu-berlin.de
markusschulze at planet-interkom.de