James replying to Mike. >MMPO meets FBC, WDSC, and SFC.
(All criteria that Mike made up, I think.) If we're comparing MMPO to beatpath(wv), then the only new compliance listed above is FBC. More on the significance of that in a bit. >FBC is the most basic guarantee to reassure the timid, and SFC is the >most >ambitious guarantee for strategy-free voting, under the conditions for >which >that can be guaranteed. Those make a good combination. Even unenhanced, >MMPO >looks good in coimparison to Cardinal Pairwise. I wasn't really focusing on the cardinal pairwise-MMPO comparison. Instead, I was primarily comparing MMPO to things like ER-IRV, SD(wv), and beatpath(wv). However, since he brings it up, here's a quick summary: * pro MMPO: 1. LNHarm, 2. zero compromising-reversal incentive (as opposed to an extremely small compromising-reversal incentive), 3. maybe very slightly less vulnerable to burying-compression strategies (?) * pro CWP: 1. Smith, 2. Condorcet, 3. MMC, 4. CL, 5. less compromising-compression incentive, 6. much less vulnerability to burying-reversal strategies, 7. much less incentive for deterrent counterstrategies that distort voter rankings James: >If we're able to get beyond IRV, then why >not use SD, Smith//minmax, beatpath, ranked pairs, river, etc.? Mike: >1. They aren't nearly as easily and simply introduced and defined to the >public as MMPO. They don't even come close in that regard. I don't think that Mike has been involved enough in advocacy to make such a firm conclusion on this point. Few of us have, including myself of course, but I'm not making the same kind of sweeping statements. > >2. They don't meet FBC. MMPO's FBC (and, when enhanced, Strong FBC) gives >to >the more timid voters a guarantee that they have shown that they need. >As I said, Australian voters often bury their favorite, because they're >using Plurality strategy. And no one can assure them that IRV won't make >them regret that they didn't do that--because IRV can make them regret >that >they didn't do that. ... >Lesser-of-2-evils. With Cardinal Pairwise I couldn't absolutely guarantee >to >that person that that person could never regret not burying Nader lke >that. >With MMPO I could absolutely guarantee that. >That's a guarantee that voters need, as has been shown by experience. FBC. Favorite betrayal criterion. A very dramatic name. I prefer to talk about "compromising-reversal incentive", because that tells us what's actually at issue. (The name "favorite betrayal" in itself doesn't tell us whether ranking a less-preferred candidate equal to one's favorite constitutes "betrayal".) MMPO has zero compromising-reversal incentive, which is good. However, beatpath(wv) and SD(wv) already have a very minor compromising-reversal incentive, so this doesn't seem to be a strong argument for MMPO over SD(wv) and beatpath(wv). Mike's argument above is strange. He cites compromising-reversal behavior in methods with high compromising-reversal incentive (i.e. plurality and nER-IRV (that's IRV with no equal rankings allowed)) in an attempt to show that compromising-reversal will continue to be a problem even in methods with much less compromising-reversal incentive. (Aside: I personally haven't seen evidence that Australia voters frequently engage in compromising-reversal strategies, but I accept that they should do so in theory, so I won't argue the point. Still, if anyone is aware of such data, please let me know.) Why do plurality and nER-IRV have a higher compromising-reversal incentive than SD(wv) and beatpath(wv)? For one, they *don't allow compromising-compression*, which means that compromising-reversal is the only available form of the compromising strategy. Also, in SD and beatpath, there is no need to compromise at all unless there is a cycle. So, Mike argues that because voters frequently engage in compromising-reversal in methods that have high compromising-reversal incentive, we should expect voters to frequently engage in compromising-reversal even in methods that have low compromising-reversal incentive. This is not logical. Thus, his conclusion that FBC compliance is a strong MMPO>beatpath(wv) argument is not well-supported. > >As I said, I recently observed someone voting in an Internet presidential >poll, and that person agreed that Nader was more honest than the >Democrats >and had better polices. But that person ranked all the Democrats over >Nader. Is one person in an internet poll a sufficient sample size to make sweeping conclusions about voter strategy in Condorcet elections? Mike doesn't even say what the tally method was. Anyway, I wouldn't expect voter strategy in internet polls to be a good indicator of voter strategy in public elections, because (1) the outcome is totally unimportant, and (2) the electorate is more technically inclined. > >Aside from all that, though LNC isn't important to me, the fact that MMPO >meets it will help in discussions with IRVists. It meets LNHarm, but it still doesn't meet LNHelp. IRV supporters won't be impressed. LNHarm compliance by itself does little or nothing to decrease the method's vulnerability to burying strategies. > James: >There is no need to implement MMPO instead of SD. SD is just as easy to >explain Mike: >I consider SD a good proposal. But not as good as MMPO. Okay, maybe MMPO is easier to explain than SD(wv). But I expect that the aesthetic impact of its MMC failure would be a substantial impediment to public selling. When it comes to merit, I believe that SD(wv) is clearly ahead, and that SD(wv) is much less likely than minmax to seriously embarrass pairwise count methods in general. Sincerely, James Green-Armytage http://fc.antioch.edu/~james_green-armytage/voting.htm > > ---- Election-methods mailing list - see http://electorama.com/em for list info