<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">Warren has written a bit about it here: <a class="moz-txt-link-freetext" href="https://rangevoting.org/BtrIrv.html">https://rangevoting.org/BtrIrv.html</a>
(He states that every Condorcet method fails mono-add-top, which I don't
think is true, but his example does show that BTR-IRV fails mono-add-top.)
</pre>
</blockquote>
<br>
All Smith methods fail mono-add-top, but MinMax Margins meets
both Condorcet and mono-add-top.<br>
<br>
(One of it's alternative algorithms is just elect the candidate
who needs the fewest extra bullet votes to<br>
be the CW.)<br>
<br>
But looking at that link I saw something different:<br>
<blockquote type="cite">Like IRV, it suffers from "<a
href="https://rangevoting.org/AddTopFail.html">add-top failure</a>."</blockquote>
<br>
Of course IRV meets mono-add-top. A candidate can only be
eliminated by having a shortage of top-rankings.<br>
No ballot's lower rankings can have any bearing on the result
until the higher-ranked candidates have been <br>
eliminated. <br>
<br>
So if X is winning and then we add some ballots with X voted top,
X cannot possibly be harmed if the method<br>
is IRV.<br>
<br>
Chris Benham<br>
<br>
<br>
</p>
<div class="moz-cite-prefix">On 7/12/2019 9:52 am, Kristofer
Munsterhjelm wrote:<br>
</div>
<blockquote type="cite"
cite="mid:8dd6b5fe-4eee-cb80-56c1-8442e27e0302@t-online.de">
<pre class="moz-quote-pre" wrap="">On 06/12/2019 13.48, <a class="moz-txt-link-abbreviated" href="mailto:fdpk69p6uq@snkmail.com">fdpk69p6uq@snkmail.com</a> wrote:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">Has BTR-STV been used in the real world or analyzed academically? There
are only two sentences about it on Electowiki.
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
Warren has written a bit about it here: <a class="moz-txt-link-freetext" href="https://rangevoting.org/BtrIrv.html">https://rangevoting.org/BtrIrv.html</a>
(He states that every Condorcet method fails mono-add-top, which I don't
think is true, but his example does show that BTR-IRV fails mono-add-top.)
On a funny note, a dance contest program on TV here uses a judging
method that could be seen as a variant of BTR-IRV (if you're willing to
be very generous). It works like this:
At the end of each program, the judges provide their rating of the
contestants, and then the callers provide their rating by number of
calls and web votes. Those are combined to produce an overall rating,
and then the two bottom contestants do a repetition of their dances,
during which the callers vote on who gets to continue on to the next
program and who is eliminated.
It's "like" BTR-IRV since there's a ranking, and the bottom two are
subject to a runoff, and the loser of the runoff is eliminated. But it's
a real runoff (not instant), and the initial "round" (program)'s ranking
is based on ratings, not on first preferences.
I don't think BTR-IRV has been used in public elections anywhere, unlike
Borda-elimination (as you point out below).
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">I know Nanson/Baldwin methods have both going for them, and they're
Condorcet and relatively simple to explain to someone familiar with IRV:
"Instead of eliminating the candidate with the least number of
first-preference votes (which results in vote-splitting and discards
some voters' preferences), you eliminate the candidate with the worst
average ranking."
"In contrast to the Borda rule, our experiments with Baldwin’s and
Nanson’s rules demonstrate that both of them are often more difficult to
manipulate in practice. These results suggest that elimination style
voting rules deserve further
study." <a class="moz-txt-link-freetext" href="http://dx.doi.org/10.1016/j.artint.2014.07.005">http://dx.doi.org/10.1016/j.artint.2014.07.005</a>
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
James Green-Armytage's paper on strategic resistance seems to put
Nanson/Baldwin around the same manipulability level as Minmax.
<a class="moz-txt-link-freetext" href="http://jamesgreenarmytage.com/strategy-utility.pdf">http://jamesgreenarmytage.com/strategy-utility.pdf</a> page 18.
----
Election-Methods mailing list - see <a class="moz-txt-link-freetext" href="https://electorama.com/em">https://electorama.com/em</a> for list info
</pre>
</blockquote>
</body>
</html>