[EM] Hybrid Beats-All/Approval v. Straight Approval

Bart Ingles bartman at netgate.net
Wed Oct 24 22:19:30 PDT 2001

Forest Simmons wrote:
> However (in defense of Rob's point of view) it seems to me that if a
> method yields results that make people regret sincere voting, then voters
> can be manipulated by mis-information into an unsatisfactory result.
> If voters are satisfied (after the fact) with their sincere vote (i.e.
> they wouldn't change it if the election were repeated) then their vote is
> less likely to be manipulated by mis-information.
> I believe that the candidate with the greatest sincere approval is the one
> most likely to serve the best interests of the electorate as a whole.
> Furthermore, under Approval, when votes are not sincere, they tend to be
> bent towards the beats-all winner, as long as horse race style polls are
> accurate. That's OK, it just saves us the trouble of inserting a beats all
> feature into our method.
> I'm still worried about the case when poll information is inaccurate for
> whatever reasons.
> Suppose, for example that sincere ballots would have been ...
> 55 B >> A > C
> 45 A > C >> B
> but the polls are falsified to say that neither B nor A has much of a
> chance ... that C is way out in front.
> Then it would be natural for the first faction to graduate A to approved
> status. Then A would be the Approval winner, even though B was both the
> sincere approval candidate and the CW.
> As I see it, checking for a beats all winner (and saving the approval
> winner for tie breaker) relieves some of the stress associated with
> strategic voting (i.e. the worry that you may be basing your strategy on
> inaccurate horse race information).

It seems to me that any time strategic (i.e. polling) information is
potentially useful, the election can be manipulated by supplying
inaccurate polling data.  Checking for a beatsall winner doesn't prevent

The difference is that with Approval, the manipulation would tend to be
most effective when the voter is ambivalent towards a candidate, so that
it doesn't take too much of a push either way to influence that voter.

Ranked systems are more susceptible when the voter is indifferent
between some pair of candidates (even though the voter may have a strong
opinion either for or against both candidates).

About the only system I've ever heard of which wouldn't be susceptible
to bogus polls would be a random drawing, such as where each voter
writes a name on a scrap of paper and tosses it into a hat.  The
probability of a candidate winning would be proportional to the number
of voters for whom that candidate is a first choice, and there is no
incentive for any voter to falsify his/her first choice.  So at least it
passes FBC, although it fails either non-imposition or non-dictatorship
(or both?).

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