Kevin Venzke <stepjak <at> yahoo.fr> writes: > Beatpath(wv) satisfies clone independence, monotonicity, > plurality, minimal defense, Condorcet Loser, Local IIA, > always elects from Schwartz, always elects from the CDTT.. > It'll be very hard to meet the same properties if you > design method from scratch.
Fair enough. The biggest problem I have with beatpath is that I CAN'T ACTUALLY ELECT ANYONE WITH IT. (sorry if that looks like shouting, but I can't emphasize that point enough) No one is using beatpath in the real world. I actually *can* elect people with IRV (since I am lucky enough to live in San Francisco), even though most election methods geeks know it's inferior to condorcet methods. Why is that? (and more importantly, why is plurality still so much more common than any ranked system?) I don't question that meeting lots of criteria is good, but sometimes I question whether some of the people on this list tend to see things in such black and white terms that they are really missing some important points. For instance, with regard to, say, the "clone independence" criterion: is it possible that two methods both technically fail this criterion, but that one does a whole lot better than the other on it? For instance, plurality utterly fails this. Minmax....seems to me that it would only affected by clone candidates in the most contrived situations. I think that saying that something "fails", without saying "how badly it fails", is misleading. So if MinMax (or the "MinSum" method I proposed) fails some criteria, but "only by a little bit", while having other desirable properties that can make it more "marketable" (i.e. you can actually explain how it is tabulated to regular people in a way they will understand, and show the results in a way they will understand), I think that could far outweigh its technical imperfections. > I'm not so convinced that it's valuable > for a method to be tunable. I can't imagine how you could really use > this to fix a perceived problem. Well, let me give an example of tunability that currently exists in the real world: the "two-thirds majority" required to, for instance, ammend the US constition. Why two-thirds? It's not a magic number. It could have been three-fourths (as it is for final adoption of any constitutional amendment in state legistatures), or three-fifths, or 70 percent, or whatever. Such a thing is inherently tunable, by simply adjusting a variable, rather than by selecting a completely different system. Typically the value is not going to be adjusted for each election but it will be selected when framing a new constution or by-laws, allowing the framers to select whatever value they want to strike the right balance (in this case between flexibility and stability). Now, with electing a single candidate, things are different, but tunabilily could still be valuable. Here is an example: Say one election method tends to pick a non-controversial, middle ground candidate. Someone that doesn't offend anyone but isn't necessarily loved by many people either. Say another method tends to favor a candidate that is strongly favored by many, disregarding whether that candidate is despised by a few. Now, wouldn't it be nice if you could, when writing a new constitution or by-laws, decide the exact balance that is desired, to encourage harmony while also allowing for healthy debate? Rather than having to say "should we use beatpath or minmax or approval or IRV or plurality?", they could say "we'll use the Tun-o-matic system with the harmony factor set to .7". -rob ---- election-methods mailing list - see http://electorama.com/em for list info
