From: "James Green-Armytage" <[EMAIL PROTECTED]> Subject: [EM] orphaned voting method (snip) It works like this:
1. Ranked Ballots. 2. Count top choice vote totals. 3. Hold a pairwise comparison between the two candidates with the lowest top choice vote total. 4. Eliminate the loser of this pairwise competition. 5. Continue until no more candidates can be eliminated. (One candidate remaining, or a set of tied candidates.)
This method is Condorcet efficient, in that it will always select a
Condorcet winner, and never select a Condorcet loser.
I am not suggesting that it is superior to beatpath or ranked pairs (I of
course have examples where it doesn't do what I want it to do), but it is
a good method to keep in mind when discussing variations on IRV. I haven't
evaluated its strategy properties; that might be interesting.
Does anyone know the name of this method or who invented it? I think that
I read about it somewhere, but I can't remember where.
James
(JBH) I presume that, like IRV, this method eliminates losers only until one of the remaining candidates gets a majority? In other words, it (5) continues until no more candidates need to be eliminated.
I get the news from www.fairvote.org, about efforts to enact IRV in U.S. localities. Sometimes they forward newspaper articles by journalists, who frequently describe IRV as "complicated". Sometimes "very complicated". Although the argument is absurd, ALWAYS somebody makes the argument that ranked ballots are "too complicated".
Assuming that this discussion list is not purely for entertainment, i.e. we hope to actually persuade the U.S. electorate to ADOPT some of these methods, IMHO simplicity is a MAJOR virtue. Methods that could practically be done with paper ballots counted by hand, with all calculations done by hand with pencil and paper by High-School graduates, are in a WHOLE DIFFERENT CLASS than methods requiring computers. Methods that can be described in a few short sentences are in a WHOLE DIFFERENT CLASS than methods that need several paragraphs to explain.
Some time back I asked why the folks here worked so hard to find other methods of Proportional Representation when we had Party List and STV, which seemed to cover all the necessary bases. People responded with their complaints about both methods.
IMHO the major virtue of Party List is its simplicity. The major advantage of IRV is that it is the one-seat case of STV, which is the best PR method that has been widely tried. American voters who manage to get over the hurdle of understanding IRV are that much closer to understanding (and hopefully accepting) STV.
A good part of my interest in Generalized Bucklin is that it could be a "unified method" for both PR and single-seat elections. That is itself a plus on "simplicity".
The complaints against STV, as I recall, boiled down to "just like IRV, STV will sometimes eliminate the wrong candidate". It is not monotonic, so sometimes you get spoiler effects and perverse incentives.
The orphan method is one step more complicated than IRV/STV, but it is still a "simple" method.
SO: I am wondering what effects you would get if you applied the orphan method's elimination rule to multiseat STV? How would the results compare with "Sequential STV" or "CPO-STV", both of which are complex and computer-dependent? If the orphan method significantly improves the performance of IRV, would it similarly reduce the complaints here against STV?
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John B. Hodges, jbhodges@ @usit.net
Do Justice, Love Mercy, and Be Irreverent.
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