What Copeland Counts

[Mike Ossipoff]

Any Pairwise method, even Copeland or Regular Champion, starts
out by counting voters, to determine which alternative beats which.

But then, if there's a circular tie, that's where Regular Chammpion
parts ways with counting votes. Because now it's candidates that
it counts. The preference voters that the voters cast are no longer
used.

Here's an example that I posted once before:

Say you're part of a group that's voting on what movie to go to
on a particular evening. Say there are Westerns, crime movies,
& adventure movies, and Regular Champion, or some Copeland version,
is used.

Say more voters prefer Westerns to crime movies than vice-versa,
so all the Westerns beat all the crime movies. Similarly, the
crime movies beat the adventure movies, and the adventure
movies beat the Westerns. So it's a circular tie.

Now, say there are lots of crime movies, and very few adventure
movies on that particular evening. This means that a Western
will win, by Copeland's count rule. The number of movies of
the various genres playing that evening determines which 
Genre will win. Nonsense. Copeland is nonsense. The voters are
what should matter, not how many movies of each type are
playing, in determing which genre the winning movie comes from.

Of course it could just as easily have been political parties
& candidates instead of genres & movies. What kind of a way
is that to pick a winning party? 

And since Copeland is so indecisive--completely indecisive in
a 3-candidate circular tie--what if we were to ask what the
justification is for choosing the winner by plurality?

***

Mike






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