On 22 Apr 2005 at 18:42 UTC-0700, Russ Paielli wrote: Araucaria Araucana araucaria.araucana-at-gmail.com |EMlist| wrote: > >> Consider this case. Original true preferences: >> 27: A>B >> 24: B>A 49: C >> A is the Condorcet winner. Now consider what happens if B defects >> via >> truncation: >> 27: A>B >> 24: B >> 49: C >> Under RP(wv), Beatpath(wv) or DMC, B wins. B voters have gotten a >> better result by dropping a lower preference. This is an example of >> the "Later No Hurt" violation of Condorcet completion methods -- B >> voters hurt their favorite by adding a lower-ranked preference. >> But if A puts the approval cutoff above B, B can't win in DMC: >> 27: A>>B >> 24: B >> 49: C >> C wins, anyway you cut it, as you found. There's no LNHurt >> situation >> here because B can't win either way. So the best the B voters can do >> is to add a preference for A. That's what I mean by the poison pill >> (by the A voters). Is it clear now? > > Ahhh...yes, now I see what you meant. As you pointed out, however, > this particular situation is apparently no worse for DMC than it is > for popular (on EM) Condorcet methods (or Approval). Are you saying > that, with an approval cutoff (i.e., ranking allowed for unapproved > candidates) that DMC actually has an advantage over those Condorcet > methods? If so, then I am certainly willing to reconsider allowing > an approval cutoff.
Yes, I am saying that this is a major advantage for DMC. It has the same effect as ATLO, but does not require a recount. AWP has the same advantage. But AWP requires an extra pairwise array for the strong preference votes. You should actually try reading James' papers on CWP and AWP -- the extra AWP array is actually the same as DMC's with all above-cutoff votes and below-cutoff votes set to equal-rank. I actually think AWP would be an excellent proposal (say along the lines of Jobst's "grand compromise"). I just worry about the complexity of implementation. > > Note, however, that the added equipment requirement for an approval > cutoff could delay the adoption for decades, but I won't get into > that now. Or you could add an extra "candidate" to set the cutoff level. No new equipment. > > Let me just suggest another possible approach to the problem: > auto-truncation. This idea is probably unoriginal, and it is also > probably meritless, but let just throw it out there anyway as a long > shot. This idea could be applicable to other methods too, but lets > just consider DMC/RAV. > > Suppose we determine a tentative winner using the standard DMC > rules. Now we "suppress" (tentatively eliminate) all the > non-first-choice votes for that tentative winner, then determine a > new winner. For all the voters who had the new winner ranked above > the previous tentative winner, keep that previous winner > "suppressed", but for all who didn't, unsuppress (restore) the votes > for the previous winner. Repeat until the process converges to a > stable winner. > > Will this procedure always converge? If so, has it been proposed > before, and is it equivalent to some other, perhaps simpler, method? Is this procedure summable? It sounds like it requires recounts. > > >> So a good DMC strategy is >> Rank all candidates you are willing to see elected, from your >> favorite to your "hold-your-nose-and-swallow-just-barely-tolerated" >> candidate. > > Why not just go all the way down? Who says they wouldn't? Most voters would equal rank the remaining candidates anyway. But consider (a) the Later-no-harm violation, and (b) time required to rank 150 candidates [extreme CA governor recall case]. > >> Put your approval cutoff just below the candidate with the best >> shot at winning. (I think this is Forest's Approval voting >> criterion). >> Here, that means that the A voters cutoff below A. >> B voters, realizing this is the strategy, will add a lower >> preference >> for A. >> C voters, if they realize they're in the minority, might then decide >> to rank their preferred opposition alternative below the cutoff. If >> they despise A, they might actually vote for B in sufficient numbers >> to turn the election around. >> But you don't get this effect if you remove the approval cutoff. >> >>>Those schemes might or might not be acceptable. I realize they seem >>>very simple to you, but I think they may still be too complicated >>>for major public elections. Also, I don't like the idea of requiring >>>the voter to actually write a number. That's asking for trouble >>>because the written number will sometimes be ambiguous. >> I find writing a number to be much faster than filling in an optical >> cell! > > I don't think optical cells are the answer either. What you want is > a nice, simple touch-screen (or mouse based) system. And yes, of > course you need to generate paper ballots too. Absentee ballots? > >> >>>I envision something like the Graphical Voter Interface (GVI >>>http://ElectionMethods.org/GVI.htm) that I developed a while back >> Can't see the screenshots: >> Permission Denied >> The area you are trying to access has been closed off by the >> server >> administrator. > > OK, I fixed it. Take a look at it. > >> >>>just for kicks. It has a column of buttons, each about a half inch >>>high by 3 inches wide, with a candidate's name and party on each >>>one. You select them in order of preference by simply touching them >>>on a touchscreen (or clicking on them with a mouse on a conventional >>>monitor). You can always backtrack, of course. You can specify equal >>>rankings by touching a selected candidate a second time (GVI doesn't >>>currently allow that, but it could be added). >> Woowee. Screen takeover. Watch those colors and fonts! > > I don't understand what you mean by "Screen takeover." Well, on my computer it is a full screen application with loud colors ;-). > >> I'm not sure I find that more intuitive. >> Anyway, I favor paper ballot counting, period. Machines would be >> used >> only for assistance. What does your software do then? > > Yes, GVI can print paper ballots. However, this feature is just a > prototype. it just prints the ballot to a conventional printer. > -- araucaria dot araucana at gmail dot com ---- Election-methods mailing list - see http://electorama.com/em for list info
