[EM] Need IRV examples; voting show

[Bart Ingles]

James Gilmour wrote:
> 
> [...]  Publishing "results"
> precinct by precinct is just totally irrelevant when all that matters is the
> city-wide totals.  It is not a question of keeping them secret.  Rather the
> question is why on earth would you want to publish such irrelevant information?

Freedom of information, public accountability, etc.  One example of
where it was used was Florida in 2000-2001, where several news
organizations were able to examine the presidential ballots and
eventually discount claims that a selective recount would have changed
the outcome.

Also, I don't consider information pointing to the defectiveness of an
election or electoral system to be irrelevant.


> > In return,
> > approval ballots contain information not present in ranked ballots,
> > namely an indication of the voters' strength of preference.
>
> I don't buy that.  In Approval each voter just sorts the candidates into two
> sets - acceptable and not acceptable.  That seems to me to be LESS information
> than on a typical ranked ballot.

I didn't say that approval ballots necessarily contained more
information than ranked ballots, I said that approval ballots contained
information not present in ranked ballots, and that the information on
an approval ballot is less prone to being used in a haphazard way.

With ranked ballots, there is no way to determine who is acceptable or
not acceptable, except for the first and last preferences.


> If you really want information about "strength
> of preference" you will have to introduce some system that allows each voter to
> weight his or her preferences as they wish.  Then you must normalise those
> weightings if you want to ensure that each voter has one vote and only one vote.
> And of course, in normalising the weights, you will throw away a significant part
> of the information about the differences in the strengths of preference BETWEEN
> voters.

Only if you insist on finer granularity than acceptable/not acceptable. 
And I don't buy your interpretation of "one and only one vote"-- I don't
believe the phrase was ever intended to apply to voting methods other
than first-past-the-post, in the context of people actually voting
multiple times for the same candidate.


> > In computer models conducted by Merrill and others, approval voting
> > produced results more in line with Condorcet's method than did IRV,
> > especially when there are many candidates.
> 
> Maybe, but that does not remove the serious defect in Approval.  One person, one
> vote is violated.

If that's true, it's also violated in every other method except
Plurality.  It's especially bad in IRV, where one voter may have votes
counted for several candidates, while another has only one choice
counted.

With Approval everyone gets exactly one vote per candidate, and the vote
may be to "approve" or "not approve."  And as has been pointed out, with
approval any individual voter can vote in such a way as to cancel out
any other voter.


> > This is even more true when
> > the IRV variant is a restricted one, such as the "supplemental vote"
> > method used in London (where the voter is only allowed a first and
> > second choice).
> 
> The Supplemental Vote is highly defective and should NEVER be used.  It will
> usually disenfranchise a large proportion of those who vote.  In the London
> Mayoral election, 22% of the second preferences were discarded because they were
> not cast of either of the two front-runners.

At least we agree on something, although it didn't sound so bad back
when I was an IRV supporter.  At the very least, it could be improved by
letting second preferences be voted as in approval voting-- in other
words one first choice and any number of second choices.  Not an ideal
system, but probably an improvement over two-round runoff, and maybe IRV
depending on your criteria.  Certainly better than SV as it stands.

Bart

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