Why ranked and not graded ballots? This method would be consistent with non-normalized ballots (with no top-ratings or no bottom-ratings) being strategically optimal in some cases, arguably in most real-world cases. As Balinski and Laraki argue, using commonly-understood ratings/grades is the only way to avoid having strategy be, not just a consideration in rating, but the only logically coherent one. And it's easier, cognitively, to separately rate each candidate on a meaningful scale than to sort them into a rank order.<div>
<br></div><div>Jameson<br><br><div class="gmail_quote">2011/11/20 C.Benham <span dir="ltr"><<a href="mailto:cbenhamau@yahoo.com.au">cbenhamau@yahoo.com.au</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<br>
Forest Simmons wrote (17 Nov 2011):<br>
<br>
MTA vs. MCA<br>
<br>
I like MTA better than MCA because in the case where they differ (two or more<br>
candidates with majorities of top preferences) the MCA decision is made only by<br>
the voters whose ballots already had the effect of getting the ”finalists” into<br>
the final round, while the MTA decision reaches for broader support.<br>
Because of this, in MTA there is less incentive to top rate a lesser evil. If<br>
you don’t believe the fake polls about how hot the lesser evil is, you can take<br>
a wait and see attitude by voting her in the middle slot. If it turns out that<br>
she did end up as a finalist (against the greater evil) then your ballot will<br>
give her full support in the final round.<br>
<br>
<end Forest quote><br>
<br>
I buy this. I agree that MTA is a bit better than MCA. Well done Mike.<br>
<br>
* Voters submit 3-slot ratings ballots, default rating is Bottom signifying least<br>
preferred and not approved. Top-rating signifies most preferred and approved.<br>
Middle-rating also signifies approval.<br>
<br>
If any candidates are Top-rated on more than half the ballots, elect the one of<br>
these with the most approval.<br>
<br>
Otherwise elect the most approved candidate.*<br>
<br>
A slight marketing problem could be that the difference between this and MCA<br>
(and also between those and a third possible similar method: the TR winner wins if<br>
s/he has majority approval, otherwise the most approved candidate wins) could<br>
to some members of the public appear to be quite arbitrary and unimportant.<br>
<br>
Also of course MTA is little bit more complex to count than MCA. But on the positive<br>
side, it has just occurred to me that it would work better than MCA extended to using<br>
4-slot ballots (with as with 3 slots, any rating above the bottom-most slot is interpreted<br>
as approval).<br>
<br>
I suppose by the same reasoning we could improve ER-Bucklin(whole), which has<br>
been given the briefer and quite apt new name by Mike O. of "ABucklin".<br>
<br>
My stab at defining the so improved version:<br>
<br>
*Voters submit ranking ballots, equal-ranking and truncation allowed. Ranked (i.e.not<br>
truncated) candidates are considered to be approved.<br>
<br>
Rankings are interpreted as ratings thus: candidates ranked below no others are in the top<br>
ratings slot. Those with x candidates ranked above them are in (x-1)th. ratings slot from<br>
the top. (So A=B>D is interpreted as A and B in top slot, second-highest slot empty,<br>
D in third-highest slot).<br>
<br>
Say the ratings slots are labelled from highest (signifying most preferred) down as alphabetical<br>
grades A, B, C, D etc.<br>
<br>
If any candidates are graded A on more than half the ballots then elect the most approved one<br>
of these.<br>
<br>
Otherwise if any candidates are graded A or B on more than half the ballots then elect the most<br>
approved one of these.<br>
<br>
Otherwise if any candidates are graded A or B or C on more than half the ballots then elect the<br>
most approved one of these.<br>
<br>
Continue in this vein considering the next lowest grade each round until there is a winner, or if<br>
that fails then elect the most approved candidate.*<br>
<br>
I think IBIFA is still quite a lot better than any of these methods, but it is more complicated.<br>
IBIFA has a less strong truncation incentive and the IBIFA winner will never be pairwise-beaten<br>
by the winner of any of these methods.<br>
<br>
Chris Benham<br>
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</blockquote></div><br></div>