[Election-Methods] Improved Approval Runoff
Abd ul-Rahman Lomax
abd at lomaxdesign.com
Wed Aug 15 21:50:19 PDT 2007
At 04:00 PM 8/15/2007, Diego Renato wrote:
>All one-round voting systems that allows ballot truncation are
>vulnerable to bullet voting, resulting the same results of plurality voting.
"Vulnerable" implies that there is something wrong with this. It is
not correct to claim that this gives "the same results" as plurality
voting. That's only true if *all* voters bullet vote. And if that is
what they want to do, who are we to say that they should not?
> For instance, suppose that some voter has A as his/her first
> preference. S/he can vote like this:
>
>Approval: A: approved; B: rejected; C: rejected; D: rejected ...
>Range (0 - 100 scale): A: 100; B: 0; C: 0; D: 0 ...
>Preferential (IRV, Condorcet, etc): A>B=C=D=...
Yes. What's the problem? In a good method, if truncation results in
no majority winner, that is, majority consent to the win is not
apparent from the ballots, there should be a runoff.
>Additionally, there are several instances which only binary input
>voting systems are reasonable. Complex systems are hard to adopt in
>low-educated underdeveloped countries.
>
>This system, called Improved Approval Runoff (IAR), has the goal to
>resist bullet voting through simple ballots.
I'm mystified as to why we should "resist" bullet-voting.
>Description:
>
>1) On the first round, the voter can vote for as many or as few
>candidates as desired.
>2) If some candidate has more than 50% of approvals, the most
>approved is elected.
>3) If not, that candidate runs a second round against other
>candidate - the most approved after a new count which the votes for
>the first one are reweighted to 1/2.
>4) The winner is the candidate who receives a majority of votes on
>the second round.
It seems with the reweighting that it is assumed that the voter only
votes for two, otherwise why that particular reweighting?
I'm not sure I understand the "second round." The expression was a
bit garbled, I suspect. I assume that the "second round" is not an
actual runoff, but a recounting. As written, it would seem manifestly
unfair to the first candidate, the plurality winner of the approval election.
There is no way to guarantee that a candidate gets "the majority of
votes" except by redefining votes to mean something other than "the
majority of voters approve this outcome of the election." (Top two
runoff does it by a trick: the voters only have two choices, and any
ballot which does not select one of them is discarded. This is
actually a failure of democracy, election results, when possible,
should always be ratified by a majority. That's what happens in small
societies using full democratic process, this step is only skipped in
large elections, supposedly for efficiency.
However, Asset Voting methods could make real runoffs and
ratifications quite efficient.
>On computer simulations, the top-two approval runoff method selected
>more times the Condorcet winner than any Condorcet method. I think
>that IAR is slightly fairer than top-two approval runoff under real voters.
Again, I don't think that's true. Approval is *not* guaranteed to
pick the Condorcet winner, no matter how you slice it, and any
Condorcet method, by definition, will. That is, a Condorcet method
*always* finds the Condorcet winner if voters vote sincerely, and
there are few reasons to treat the matter as if they will not.
however, the Condorcet winner is not necessarily the best winner;
Approval may, indeed, select a better winner, as shown by social
utility simulations. Approval begins the progression of Range
methods, which match the very method of measuring what it means to
have a good result. ("Condorcet Criterion" can be shown to manifestly
make a poor choice under certain conditions, it really is not
controversial. That is, a small society would *never* choose what the
Condorcet Criterion would indicate should win, given sufficient
knowledge, under certain conditions, basically those of a majority
with a sufficiently weak preference and a minority with a
sufficiently strong one. Who decides, properly, when such a condition
should result in the violation fo the Majority Criterion?
The majority, but it is crucial that the decision be explicit.
What I have suggested is that Approval have a preference marker
added. I called this A+; that is, Approval with a "Plus" indicator
that shows preference. This marker could be used for more than one,
but the general intention is that it would be used to show the
Favorite. The ballot then indicates the set of approved candidates --
these are considered acceptable under the present conditions by the
voter -- and the favorite -- or favorites -- as well.
However, initially the ballots are counted without regard to the Plus
marker. It's an Approval election, initially. Now, with basic A+,
that's it. The Plus marker is used for analysis of election results,
allocation of campaign funding, and other informational purposes.
But having this preference information allows a new possibility, I
called it A+/PW, for Approval Plus, Pairwise. If the ballots show
that there is a *different* winner through pairwise analysis, using
the Plus markers as well as the other Approval Votes, then there
would be a runoff election between the Approval winner and the
most-approved candidate who beats the Approval winner.
This version of Approval is Majority Criterion compliant, but through
a trick: it's the majority in the runoff that counts. Nevertheless,
this is far more democratic. It is much closer to an explicit
ratification of the election.
I would also trigger a runoff if there were no candidate with
majority Approval. If there was no candidate who beat the Approval
winner pairwise, the runoff could be between the top two Approval candidates.
But Asset Voting is better.... And the Asset Ballot is extremely
simple; it is a basic Approval ballot.
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