[EM] several replies

Warren Smith wds at math.temple.edu
Sun Jul 9 04:11:42 PDT 2006


> raphfrk at netscape.net
>What about using the following for the electoral college.
>A State can split itself into sub-States as long as all sub-States have
>a population larger than the smallest State

- this is all a bad  idea since it makes the presidential election subject to
gerrymandering.  The present EC system is bad but at least it cannot be gerrymandered.

> IRV with candidate withdrawal (F Simmons)

- WDS: My preliminary computer simulation includes this.  The preliminary result
was that in 3-candidate IRV elections, allowing the runner-up to retroactively
withdraw from the race improves IRV's Bayesian regret, and in the 1-dimensional scenarios
in my sim, it turned out the Condorcet winner always resulted from this
procedure if the guy withdrew whenever (by so doing) he could make
the winner closer to him on the 1D line.   However, keep in mind this
claim is preliminary.  It perhaps can now be proven as a theorem (now that the
computer+me noticed it) in 1D "singlepeaked" scenarios with 3 candidates.

>Burr dilemma problem with approval voting pointed out by Nagel and used
>by Rob Richie to attack Approval voting:
>The key slide from Nagel's presentation:

>Statement of the Burr Dilemma

>When three or more candidates compete for an office that only one can
win, and voters (V) may support two (or more) of them by casting
equal (approval) votes, candidates (C1 and C2) seeking support from
the same group (G) of voters will maximize their respective votes if
all members of G vote for both C1 and C2.   Both candidates thus have
an incentive to appeal for shared support.  However, if such appeals
succeed completely and neither candidate receives votes from members
of V-G, the outcome will be at best a tie in which neither C1 nor C2
is assured of victory.  Each candidate therefore has an incentive to
encourage some members of G to vote only for himself or herself.  If
both C1 and C2 successfully follow such a strategy, either or both
may receive fewer votes than some other candidate C3 supported by
members of V-G.  The risk that both C1  and C2  will lose is
exacerbated if a retaliatory spiral increases the number of single
votes cast by members of G.  At the limit, such retribution reduces
approval voting to conventional single-vote balloting among the
members of G or, if the problem is endemic, among all voters.  The
nearer that limit is approached, the lower the probability that
advantages claimed for approval voting will be realized..

--WDS RESPONSE:
I think Nagel has a valid point.  You might have thought
Approval voting was immune to "candidate cloning."
However, due to these strategic-voting "retaliatory spiral" effects
that actually is not so in real life.
Therefore, "vote splitting" effects can still occur in approval
voting, contrary to advertising.

However in range voting, voters can still vote, say, C1=99, C2=97
thus expressing a slight preference without hurting the C1,C2 candidate
set too much.  So, in practice we can expect that
range voting would alleviate this Burr-dilemma problem
with approval voting pointed out by Nagel.

So that seems to be another advantage of range over approval.

Oho, I see Anthony O'Neal had a similar response.  Clearly the man is a genius,
he should join the Center for Range Voting,  http://www.rangevoting.org .
--Warren Smith




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