David L Wetzell wetzelld at gmail.com
Tue Jan 31 12:23:23 PST 2012

> Why STV? The original poster wanted elected representatives to have votes
> proportional to their electoral support yes? There's no need for fractional
> transfers from elected candidates then.
> >
> IRV is a form of STV, but it's not my favorite.  Some of the other STV
> methods (e.g. Schulze-STV and CPO-STV) tend to produce better eliminations.
> But the question of why not STV is a good one.  Several reasons.
> STV requires much more work on the part of the voter - ranking all the way
> down to a candidate likely to be elected, instead of just one.  That
> probably means a much larger ballot and/or an arbitrary cutoff between
> ballot-candidates and write-in candidates.

dlw: If the number of possible rankings is the number of seats + 2 then
it's not too bad.  And nobody would be forced to rank umpteen candidates,
so the low-info voters could just vote for their favorite candidate.

> The STV variants that are less strategy-prone are computationally
> inefficient, and even those are not strategy-free.
> And perhaps most importantly, the more resistant an STV method is to
> strategy, the more complicated it is to explain and understand.
> As deterministic methods go, I do like STV methods; but DS fixes a lot of
> the worries I have about them.

One could also apply the same sort of approach to simplifying STV with the
initial treatment of all of the rankings as approval votes to get the
number of candidates down to N+2, where N is the number of seats.

As with IRV, it's easier to explain STV when there's relatively few
candidates to eliminate.  And, it'll mitigate the strategy effects, which
have to be examined more closely.  As I argued before, there's a diff
between making 3rd party dissenters vote strategically and making the
supporters of a major party out of touch with most voters vote
strategically.  The possibility that their voters get pushed to vote
strategically is an incentive for changes in candidate/party positions.  In
the FPTP case, it trims the ability of dissenters to move the de facto
center towards the true center.  In the IRV case, it does the opposite, it
penalizes the major parties when they do not move enough towards the true

Most rational choice models implicit here take as fixed the position of
candidates/parties on the spectrum, when in real life, this can be changed
somewhat.  This reduces the "badness" of strategic voting.  It becomes less
important thereby to devise an election rule that doesn't give any
incentive to anyone to vote strategically.


> ---------- Forwarded message ----------
> From: Jameson Quinn <jameson.quinn at gmail.com>
> To: EM <election-methods at lists.electorama.com>
> Cc:
> Date: Tue, 31 Jan 2012 11:04:40 -0600
> Subject: [EM] SODA is monotonic. Earlier failure/fix was actually for
> participation, not monotononicity.
> A week or two ago, I sent a message to the list with a scenario which I
> claimed was an example of nonmonotonicity in SODA as defined; and mentioned
> a natural fix for this problem (allowing partial assignment of delegated
> votes).
> I was mistaken. It was not an example of nonmonotonicity, but rather an
> example of failure of the participation criterion. The rest of what I said,
> including the simple fix for the problem, still applies.
> Jameson
> _______________________________________________
> Election-Methods mailing list
> Election-Methods at lists.electorama.com
> http://lists.electorama.com/listinfo.cgi/election-methods-electorama.com
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