[EM] Range Voting (CR), one of the best methods

[MIKE OSSIPOFF]

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Ralph Suter wrote:

Will someone on the list who has studied range voting and compared it to
Condorcet, approval, and other methods please comment on Doug Greene's 
paper? He
appears to be saying that range voting is superior to all other single 
winner
methods. Are there good arguments against this conclusion? Does range voting
have serious flaws? If so, could someone briefly summarize them?

Thanks,
Ralph Suter


It has no serious flaws.

Range Voting is also called Cardinal Ratings (CR). It's strategically 
equivalent to Approval, and that makes CR one of the best methods.

Personally I prefer Condorcet to Approval and CR, but, among practical 
proposals, Approval & CR are a close 2nd. I prefer Condorcet because I like 
the luxury of sincerely voting as many pairwise preferences as I want to, as 
many preference levels as I want to.

Approval & CR will quickly home in on the voter median, and then stay there. 
Maybe Approval or CR will arrive there after one or two elections. Condorcet 
will go there immediately.

Let me say what I mean by CR. It's probably the same thing that Range Voting 
means:

Cardinal Ratings (CR):

Each voter may give to any candidate any number of points, within some 
pre-specified range. The winner is the candidate who receives the most 
points.

[end of CR definition]

Approval, of course is a CR version, the simplest one. The 0,1 CR version.

Other CR versions include 0-10 CR, 0-100, -10 to 10, -100 to 100, and 
-1,0,1.

I say that they're all equivalent to Approval because one's best strategy to 
maximize expectation is to give maximum points to the candidates for whom 
one would vote if it were an Approval election, and give minimum points to 
the others.

Approval is my favorite, because of that equivalency, and because of 
Approval's elegant simplicity.

But Approval may be the most difficult CR version to propose, because most 
people haven't heard of it, and sometimes give a fallacious "1 person 1 
vote" objection to Approval. This isn't the place to answer that, so I'll 
just say that that objection is easily answered, in a number of ways. But it 
would be better to avoid the objection.

One way to avoid it would be to, from the start, offer Approval as a point 
system, one in which we can give to any candidate 0 points or 1 point. The 
simplest point system. Then people wouldn't misperceive Approval as illegal 
Plurality voting.

Another way to avoid that objecion, and Approval's unfamiliarity would be to 
propose one of the other CR versions. They're much more familiar. Everyone's 
been asked to rate things from 1 to 10, and so 0-10 isn't unfamiliar, for 
instance.

And the CR versions allowing negative ratings, though they're essentially 
the same as the other versions, have the great advantage that many people 
would very much like to give negative points.

For that reason, the negative points CR versions may be the most winnable of 
all. Of those, -1,0,1 is the simplest and most easily implemented. Because 
of initiatives that let us vote yes or no on a list of initiatives, we can 
implement -1,0,1 easily with existing equipment & software.

Of course the ballot needn't (but still could) offer all 3 point options 
(-1, 0 and 1). It could just offer -1 or 1; or Yes or No. Not voting either 
would assign 0 points.

CR, then, may be the most winnable of all the good voting systems, due to 
its familiarity and simplicilty. And the negative points versions might be 
the most winnable of those. And the easily-implemented -1,0,1 is probably my 
favorite public proposal among those.

With all the CR versions, as with Approval, no one ever has any incentive to 
vote someone over their favorite. That can't strictly be said for any other 
method. Of course IRV violates that criterion often. Condorcet much less so. 
Condorcete's violations of that criterion (Favorite-Betrayal Criterion, or 
FBC)
are rare, contrived, and unimportant.

Approval & the other CR versions meet WDSC:

Weak Defensive Strategy Criterion (WDSC):

If a majority of all the voters prefer X to Y, then they should have a way 
of voting that ensures that Y won't win, without any member of that majority 
voting a less-liked candidate over a more-liked one.

[end of WDSC definition]

That criterion is also met by the better Condorcet versions, the 
"winning-votes" Condorcet versions. They meet other, stronger, similar 
criteria too.
Those critreria can be found at:

http://www.electionmethods.org   at the technical evaluation page, and at:

http://www.barnsdle.demon.co.uk/vote/sing.html

Mike Ossipoff

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