<html><head></head><body><div style="color:#000; background-color:#fff; font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1493345766978_62342"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62580">Hi all,</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62343"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62344"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62345"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62916">Kristofer wrote:</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62346"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62915">>Do you consider Plurality a strategic criterion? It seems to me to be</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62347"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62914">>more of a "natural behavior" criterion</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62348"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62349"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62350"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62680">FWIW I don't consider Plurality a strategy criterion. We can bring up strategy criteria</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62351"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62681">if we wanted to, but they are more obscure than the Woodall criteria. The best known</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62352"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62682">one worth bringing up is favorite betrayal, but WV methods don't completely satisfy it,</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62352" dir="ltr"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62683">so I would be stuck talking about simulations instead of firm guarantees.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62353"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62354"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62355"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62684">(You may ask why does favorite betrayal come into it? Because the same incentives that</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62356"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62685">are supposed to discourage margins voters from truncating at the bottom, also discourage</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62357"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62686">them from equal-ranking a set of favorites at the top. And there isn't a mechanism ensuring</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62358"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62687">that ideal strategy is to simply rank them sincerely.)</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62359"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62360"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62361"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62842">I would say margins' largest issues are strategy-related, but its most obvious issues</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62362"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62841">aren't, so I prefer to talk about "natural behavior" when I have a choice.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62363"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62364"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62365"><font size="3">To Juho:</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62366"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62367"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62368"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62839">You feel criteria are "too far from practical election method considerations to be applied</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62369"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62840">directly on them as viability criteria"; that is actually very close to how I view your</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62370"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62838">criteria (even if you don't use the term "criteria"). You say the "strongest argument" for</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62371"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62837">margins is that it is a relatively natural and continuous preference function.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62372"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62373"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62753"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62754">I guess that you don't say that this involves "practical considerations," and it's just</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62755"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62756">an aesthetic preference. I give you credit for consistency in not even mentioning </font></div><div id="yui_3_16_0_ym19_1_1493345766978_62757"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62758">mono-add-top, which could easily be argued to be a practical consideration. On the other</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62759"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62760">hand you seem to believe WV has effective strategy incentives that result in things you </font></div><div dir="ltr" id="yui_3_16_0_ym19_1_1493345766978_62761"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62762">don't like, so you don't seem to completely dismiss practical considerations either.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62380"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62381"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62382"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62846">I find it more accurate when you complain that WV seems like an approval hybrid than</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62383"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62843">when you suggest that interest in WV stems from strategic defense concerns. When people</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62384"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62844">invent random new methods on EM they frequently behave like WV (or IRV); it's very hard to</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62385"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62845">emulate margins' results without actually being margins. Methods that show approval-like</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62386"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62773">behavior stem from a relatively common expectation that expressed votes are a good</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62387"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62772">indication of viability/merit. There may be good historical reasons to portray WV as a</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62388"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62771">horrified reaction to margins... And I can imagine the FPP supporter who says interest in</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62389"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62775">IRV "comes mainly from strategic defense reasons." But that seems like a limited way of</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62390"><font size="3">looking at it.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62391"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62392"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62393"><font size="3">You write:</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62394"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62898">>I think Plurality is a bit strange. Actually it is not even a criterion </font></div><div id="yui_3_16_0_ym19_1_1493345766978_62395"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62897">>of ranked methods. It is a criterion for ranked methods with implicit</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62396"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62896">>approval cutoff. It makes the assumption that a voter that casts a short</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62397"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62895">>vote has somehow approved those candidates that he marked, and not approved</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62398"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62894">>the others. In different elections the behaviour of voters with respect</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62399"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62893">>to which candidates will be marked on the ballot may vary a lot, and that</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62400"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62900">>may have nothing to do with how much the voters support or approve those </font></div><div id="yui_3_16_0_ym19_1_1493345766978_62401"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62899">>candidates. In order to make any sense of the Plurality criterion we are </font></div><div id="yui_3_16_0_ym19_1_1493345766978_62402"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62902">>thus tied to having an assumption of implicit approval in the ballots, </font></div><div id="yui_3_16_0_ym19_1_1493345766978_62403"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62901">>where marking a candidate means approving that candidate at some level.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62404"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62405"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62406"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62904">I think voters expect this behavior, and that's why it's important, for example, for</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62407"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62903">the long-term viability of the method's adoption. Now, you may say that we could </font></div><div id="yui_3_16_0_ym19_1_1493345766978_62408"><font size="3">convince voters not to expect this. You might even (though I'm still not 100% sure)</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62409"><font size="3">manage to do this by forbidding voters from truncating at all. In that case, I would</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62410"><font size="3">drop all my objections dealing with naturalness and what voters expect. My remaining</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62411"><font size="3">complaints at that point would be the strategy-related ones.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62412"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62413"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62414"><font size="3">>One reason why I don't like implicit approval in general (as a fact that</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62415"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62834">>is known by the voters) is that it encourages voters not to rank candidates</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62416"><font size="3">>that they don't like.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62417"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62418"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62419"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62951">Sure, I would rather criticize how margins addresses this than the fact that it tries</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62420"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62950">to address it. IRV does this, for instance: You can rank the worse frontrunner in a</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62421"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62948">sincere way and you know that it won't hurt you. In margins we "want" you to rank the</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62422"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62947">worse frontrunner, but it's not expected to be of any use to you, and it can </font><span style="font-size: medium;">hurt the</span></div><div id="yui_3_16_0_ym19_1_1493345766978_62422"><span style="font-size: medium;">better frontrunner by making "worse" look like your compromise choice.</span></div><div id="yui_3_16_0_ym19_1_1493345766978_62424"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62425"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62426"><font size="3">A few comments on your Plurality example:</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62427"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62428"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62429"><font size="3">>I'm not well prepared to comment how margins can handle Plurality</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62430"><font size="3">>criterion but I'll address one basic (but theoretical and extreme,</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62431"><font size="3">>i.e. unlikely to happen in typical elections) example. 35:A, 34:B>C,</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62432"><font size="3">>31:C. A has more first preferences than B has ballots where B is</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62433"><font size="3">>marked. B's worst defeat margin is however smallest (1), so it will</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62434"><font size="3">>win in typical margins based methods. Plurality criterion says that B</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62435"><font size="3">>should not win. B is however two votes short of being a Condorcet</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62436"><font size="3">>winner, so it can't be the worst of the worst. What if A would win?</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62437"><font size="3">>Plurality criterion pays special attention to A's high number of first</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62438"><font size="3">>preferences. But on the other hand voters would like to elect C</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62439"><font size="3">>instead of A with large majority (C>A voters would not be happy with</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62440"><font size="3">>the result). How about C then? Plurality criterion accepts C too, but</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62441"><font size="3">>using the high number of first preference votes of A as an argument </font></div><div id="yui_3_16_0_ym19_1_1493345766978_62442"><font size="3">>that supports C does not make much sense. My conclusion is that this</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62443"><font size="3">>is a typical mess that we can get with circular preferences. Our</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62444"><font size="3">>voters were quite stupid when they didn't sufficiently rank the </font></div><div id="yui_3_16_0_ym19_1_1493345766978_62445"><font size="3">>potential winners. There are many different possible scenarios on what</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62446"><font size="3">>the truncated opinions might have been, and different results emerging</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62447"><font size="3">>from that. In this example my recommendation would be to tell to the</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62448"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62577">>voters that they should rank all potential winners (except maybe the</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62449"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62576">>worst one). I don't see any need to start blaming (or praising) margins</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62450"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62575">>on what happened. Maybe you have some realistic examples in your mind,</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62451"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62574">>that would give better justification to the Plurality criterion.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62452"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62453"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62454"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62573">1. I just note that "fewest votes short of being a Condorcet winner" need not</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62455"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62572">strike one as a particularly less arbitrary standard than Plurality. I do not know</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62456"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62571">what stops one from dismissing yours as a criterion whose "message somehow sounds</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62457"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62570">good to people that do not regularly deal with election methods." It does "sound</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62458"><font size="3">good," I agree with that.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62459"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62460"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62461"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62569">2. I'm not sure what is your basis for calling these voters "stupid." Are you</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62462"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62568">(rhetorically) employing Plurality's assumption that voters didn't like the</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62463" dir="ltr"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62814">outcome? I get the sense that you don't like the outcome yourself.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62464"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62465"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62466"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62805">3. I do understand feeling that Plurality is strange. I don't love it. My view is</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62467"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62806">that Plurality is an easily articulated subset of a larger principle. Essentially,</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62468"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62807">if the voters were instead legislators selecting an outcome, could B ever prevail?</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62469"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62826">It seems quite unlikely, because at the moment that C is the status quo and the B</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62470"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62827">voters wish to assert their win over C, they can't because they are outnumbered by</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62471"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62828">the A voters. The pairwise contest doesn't occur in a vacuum. In this case Plurality</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62472"><font size="3">conveys what I would want.</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62473"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62474"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62475"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62849">A more thorough version of Plurality (in my opinion, to my taste) wouldn't talk</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62476"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62850">about first preferences or votes in total. I doubt this language is necessary to</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62477" dir="ltr"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62882">express the idea. (The criterion we do have is easy to apply, though.)</font></div><div id="yui_3_16_0_ym19_1_1493345766978_62478"><font size="3"><br id="yui_3_16_0_ym19_1_1493345766978_62479"></font></div><div id="yui_3_16_0_ym19_1_1493345766978_62480"><font size="3" id="yui_3_16_0_ym19_1_1493345766978_62919">Kevin</font></div><div dir="ltr" id="yui_3_16_0_ym19_1_1493345766978_62481"><br id="yui_3_16_0_ym19_1_1493345766978_62482"></div></div></body></html>