[EM] Score Voting and Approval Voting not practically substantially different from Plurality?

Kathy Dopp kathy.dopp at gmail.com
Mon Jun 24 10:28:48 PDT 2013

Please forward to the appropriate list for me.  Thank you.

From: electionscience at googlegroups.com

> [mailto:electionscience at googlegroups.com] On Behalf Of Benjamin Grant
> Sent: Monday, June 24, 2013 11:40 AM
> On Mon, Jun 24, 2013 at 11:08 AM, Stephen Unger <unger at cs.columbia.edu
> <mailto:unger at cs.columbia.edu> > wrote:
>   If you cast votes (approve or give high scores to)
> only for parties that might win the current election, then we will be
> stuck forever with the existing 2-party scam.

Yes. But the point of approval or score voting is voters do not have to do
that in order to keep their least favorite from winning.

> And under Score/Approval/Plurality voting systems, there would be three
> phases a party might go through:
> A) unpopular enough not to be a spoiler
> B) popular enough to be a spoiler, but not popular enough to win
> C) popular enough to win often (>25% of the time, for example.)

Those options apply to plurality and IRV, not to approval or score voting
where a voter's 2nd choice vote cannot cause his least favorite to win.

> On your way to C, you are going to have a LOT of B, and you may never make
> it to C, especially if people get burned voting for the emerging party by
> getting their least preferred candidate.
> Speaking re. plurality or IRV still.

> The only way to build a strong new party in reality, as far as I can see,
> is
> to have a voting system that does not penalize you into getting your least
> favored choice by voting for your most favored one.
Yes.  Agreed.

> Second of all, it seems to me that the less divergence there is between
> strategic and sincere voting, the more beneficial qualities the voting
> system has, such as:
> -we can worry less about the spoiler effect, which promotes more than just
> 2
> parties
> -we can worry less that people are accidentally voting against their
> interests
> -we can have fewer debates about whether people have an obligation to vote
> strategically or sincerely
> This would seem to be a good thing.
Ideally, but practically we may have to continue to vote for all candidates
other than our least favorates.

> *         Intelligent use of Score Voting becomes Approval Voting, and the
> harm in unwise use of Score voting means that Approval Voting is superior
> to
> (and simpler than) Score voting pragmatically.

I agree.

> *         Approval Voting tends to result in irrelevant approval votes
> being
> given to weak candidates - which is pointless, or slightly stronger (but
> still losing) candidates can once again present a spoiler effect where a
> person's least preferred choice is elected because they cast their approval
> only toward their most preferred choice, who was nowhere near supported
> enough to stop their least preferred choice.

First, why should anyone care if some votes turn out to be "irrelevant"
according to your definition?  Second, if someone uses approval voting like
plurality  byvoting for their true favorite without  also voting for their
most likely favorite candidate to win, then they are accepting that they
might spoil the chances of their other favorite(s).  Neither of these
arguments is a logically coherent reason for favoring plurality over
approval voting.

>       Am I substantially wrong about any of this? Ultimately, in real and
> practical terms, it seems that done intelligently, Score Voting devolves
> into Approval Voting, and Approval Voting devolves into Plurality Voting.
There is no logically coherent reason for approval voting to devolve into
plurality IMO.


Fundamentals of Verifiable Elections

View some of my research on my SSRN Author page:
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