# [EM] "Ranked Ossipoff Choice" is not a voting method

Chris Benham chrisbenham at bigpond.com
Sun Feb 8 10:04:12 PST 2004

Mike,
You wrote: (Sat.Feb.7):

"Plurality is a rank method? Ok, now I'm going to define a new method, which
I call Ranked Ossipoff Choice (ROC).  Here are its rules:

Voters vote rankings. The rankings are collected from the voters. Then I
make the choice, disregarding the rankings.

By your reasoning, that's a rank method too."

This (Tue.Jul.15,03) quote from Alex Small in the "Arrow's Theorem" thread has become more relevant:

"In the formal derivations of Arrow's Theorem that I've seen, an election
method is defined as a mapping from the set of voter preferences to the
set of candidates.  Show me the preference order of each individual voter,
and (barring the case of ties) I'll show you who the winner is.  No
ambiguity."

That definition is good enough for me. "Ranked Ossioff Choice" is not a ranked method, because it is
not a method.

You didn't like that Alex quote?

"That isn't correct. Voting systems have, as  their input, votes, not
preferences. ...
It's a mapping from the set of all of the  configurations of voted pairwise
comparisons that would be admissible for a given set of voters, to the set
of candidates."
Too much clarity and profundity for me to handle.

You continued:
"You'll protest that at least Ranked Plurality gets some information from the
rankings."

Yes, "Ranked" Plurality gets "some" information from the rankings, but the point is that it gets
information from NOWHERE else.

"FPP(First-Preference Plurality) is the same as FPTP(First Past The Post): it elects the candidate
with the largest number of first-preference votes." Woodall
("First past the post" is what the Plurality method is called in the UK.)

In response to me saying:

For the purpose of rationally analysing voting methods, the fact that "different voting is admissible"
is only relevant if that can possibly give a different result. (And then it is only interesting if it
makes a different viable strategy available,like equal ranking in RP versus equal ranking not allowed
in RP.)
In FPP, the only restriction on vote admissibilty that is relevant is that the voter can mark as
favourite one candidate only. Obviously it makes no difference whether voters are not allowed to enter
lower rankings or are compelled to enter lower rankings or anything in between.

You wrote:
"It makes a difference when the ballot is thrown out because it ranks
candidates. That can change the outcome of the election."

On that logic, a version of Plurality that requires the voter to check a single candidate with a tick
is a different method from a version that requires the voter to check a single candidate with a cross,
and a version that requires the voter to use a ballpoint pen is a different method from a version that
allows the voter to use a pencil, and so on.

Chris Benham