Thankyou Forest Simmons. It is appreciated.
The link is:
https://www.smashwords.com/books/view/997528
Richard Lung.
On 19/01/2020 22:30, Forest Simmons wrote:
Fascinating! We need people like you to knock us out of complacency
... out of the comfortable ruts that we inhabit.
I look forward to following the link you gave me!
On Thu, Jan 16, 2020 at 10:25 AM Richard Lung <voting@ukscientists.com
mailto:voting@ukscientists.com> wrote:
This is obviously a very learned summary that would require
considerable study to do justice to, much more than my old head is
capable of, quite apart from severe personal distresses, that have
been over-whelming our lives.
Yet, just the other day, after a half century of amateur study, to
my surprise, my naive physicists mathematical text crawled across
the finishing line of publication. Only the last chapter is of
direct interest to electoral mathematicians. It contains an
explanation of how to conduct a two-dimensional election: FAB STV 2D.
The two dimensions are Representation and Arbitration. The latter
graphs at 90 degrees (neutrally) to the former, and the count is
conducted without disturbing the normal one-dimensional count that
is FAB STV. But taken together as a complex variable the count is
according to the rules of complex variables.
from
Richard Lung.
On 15/01/2020 20:57, Forest Simmons wrote:
Just a couple of additional thoughts:
Besides Arrow and Gibbard-Sattherwaite we have lots of criterion
incompatibility results from Woodall, and defensive strategy
criteria from Mike Ossipoff, Steve Eppley, et. al.. In
particular we never worried about Later No Help and later No Harm
until Woodall came along. Venzke and Benham picked up the torch
and brought Woodall into the EM Listserv discussion.
Many EM contributors have clarified which combinations of various
criteria of more practical than academic stripe are compatible or
not: Participation, FBC, Precinct Summability, Chicken, etc.
In particular, we now know through the work of Ossipoff, Venzke,
Benham, and others that the Chicken Defense and Burial Defense
(against CW burial) are incompatible in the presence of Plurality
and the the FBC, unless we allow an explicit approval cutoff or
some other strategic switch on the ballots. Standard ordinal
ballots are not adequate for this even when truncation and equal
rankings (including equal top) are allowed. A non-standard
ballot that allows us to get compatibility to all of these except
the CC is MDDA(sc) which is Majority Defeat Disqualification
Approval with symmetric completion below the approval cutoff.
This method also satisfies other basic criteria such as
Participation, Clone Independence, Mono-Raise, Mono-Add, and
IDPA, for example.
In the context of the current discussion, the approval cutoff or
some equivalent strategic switch is essential for the
compatibility of chicken resistance and burial resistance.. No
strategy, no compatibility. So basically there is no decent
method that is resistant to both Burial of the CW and Chicken
offensives. (IRV is chicken resistant and has a form of burial
resistance, but routinely buries the CW unless voters
strategically betray their favorite to save the CW. Furthermore,
it fails mono-raise.)
Before collaborative efforts of EM List members there was no
known clone independent, monotonic method for electing from the
uncovered set. The closest thing was Copeland, which is clone
dependent.
Again the main point is that Arrow, and Gibbard-Satterthwaite are
not the "end of history" for election methods, just like the
collapse of the USSR was not the end of history as Fukuyama once
proclaimed or Thatcher's famous TINA "there is no alternative"
(to capitalism). Arrow and G-S give very valuable insights and
help us avoid cul-de-sacs, but they are not the last word in
election methods progress. The "end of history" and TINA slogans
are an excuse for giving up prematurely for lack of imagination.
We cannot allow Arrow and G-S to become excuses for lack of
imagination in Election Methods. What if Yee had given up before
inventing the beautiful Yee diagrams that constitute an
Electo-Kaleidoscope for the study of election methods analogous
to the telesope and the electron microscope in astronomy as
instruments in other branches of knowledge?
On Mon, Jan 13, 2020 at 3:32 PM Forest Simmons <fsimmons@pcc.edu
<mailto:fsimmons@pcc.edu>> wrote:
Rob,
Thanks for starting this great thread!
The "no perfect car" analogy is good. More definite is the
"no 100 percent efficient internal combustion engine" analogy
that follows from the second law of thermodynamics. It
applies to all kinds of engines, but that doesn't mean that
internal combustion is as good as it gets.
If Gibbard-Satterthwaite tells us that we cannot have all of
the nice properties we want in one election method, that
doesn't mean that one method is as good as the next.
It follows from Arrow that we cannot have the Majority
Criterion and the IIAC at the same time, but there are many
decent methods (like River) that do satisfy the MC, and a
bunch of other nice properties, like Monotonicity, Clone
Independence, the Condorcet Criterion, and Independence from
Pareto Dominated Alternatives, as well as the basic
Neutrality and Anonymity fairness criteria.
The way to think of Arrow's "Dictator" theorem is that it is
extremely hard to get a rankings based method with even
minimal decency conditions (like non-dictatorship) without
scuttling the IIAC.
In other words, no decent ordinal based method can satisfy
the IIAC, which is the same point of view that Toby and
Eppley expressed. It comes down to the mere existence of a
Condorcet Cycle. Here's the subtle part that most people
don't understand. Condorcet Cycles can exist in the
preference schedules of an election even if the election
method makes no mention of Condorcet, for example even in
IRV/Hare/STV/RCV elections:
45 A>B>C
20 B>C>A
35 C>A>B
There exists a majority preference cycle A>B>C>A even though
it causes no problem for IRV, since B is eliminated and then
C is the majority winner between the two remaining candidates.
Now let's check the IIAC. Suppose that A, one of the losers
withdraws from the race. Then the winner changes from C to
B, since B beats C by a majority. This shows that IRV does
not satisfy the IIAC, because removing a loser from the
ballot changes the winner.
But this is not just a problem for IRV, it's a problem for
any method that respects the Majority Criterion; if the
method makes A the winner, then removing B changes the
winner. If it makes B the winner, then removing C changes
the winner. If it makes C the winner, then (as we saw in the
case of IRV above) removing A changes the winner. to B.
So Arrow's "paradox" can be considered as forcing us to
realize that the IIAC is not a realistic possibility in the
presence of ordinal ballots because such ballots allow us to
detect oairwise (head-to-head) preferences, and when it comes
down to a single pair of candidates the Majority Criterion
says the pairwise winner must be chosen,
However, as someone mentioned, Approval Voting avoids this
"paradox" once the ballots have been submitted, since the
Approval winner A is always the "ballot CW," and in two
different ways:(1) For any other candidate X, candidate A
will be rated above X on more ballots than not, and (2) A's
approval score will be higher than the sore of any other
candidate. From either point of view, if we remove a loser Y
from the ballots, then A will still be the winner according
to the same ballots with Y crossed out.
That's at the ballot level. But if Y withdrew before the
ballots were filled out, it could change the winner, because
if Y were the only approved candidate for a certain voter
before the withdrawal, that voter might decide to lower her
personal approval cutoff before submitting her ballot. Or
she could raise the cutoff if Y had been the only disapproved
candidate.
As others have mentioned in this discussion, Approval Voting
externalizes the problem of the IIAC from being a decision
problem for the method itself to a strategical decision
problem for the voter. A voter might think of that as an
unfair burden.
One answer to this problem could be DSV (Designated Strategy
Voting): You submit your sincere ratings, and the DSV machine
applies a strategy of your choice or a default strategy to
transform the ballots into approval style ballots. Rob
LeGrand explored some of the possibilities and limitations of
this approach in his master's thesis. He doesn't claim to
have exhausted the possibilities. (I also have some ideas in
this vein that still need exploring.)
What constitutes a "sincere rating." One approach to that
has already been mentioned in the ice-cream flavor context in
this thread. Another is to use as a rating for candidate X
your subjective probability that on a typical issue of any
significance candidate X would support the same side you support.
It's not just Approval that requires some hard thinking in
conjunction with filling out the ballots. Ranking many
candidates (think about the number of candidates in the
election that propelled Schwarznegger into office) may be
just as burdensome as trying to decide exactly which
candidates to mark as approved. In Australia you can get
around this difficulty by copying "candidate cards" or by
voting the party line. Presumably these experts are
reflecting state of the art strategy in their rankings ...
the strategy that is indispensable for optimum results
according to Gibbard-Satterthwaite. This is not just a
problem of Approval, though it may seem worse in Approval.
In actuality, aoproval and score/range are the only commonly
used methods where optimal strategy never requires you to
"betray " your favorite.
To cut the Gordian knot of this complexity Charles Dodgson
(aka Lewis Carroll) suggested what we now call Asset Voting.
Each Voter delegates her vote to the candidate she trusts the
most to rep[resent her in the decision process. Since
write-ins are allowed, she can write in herself if she
doesn't trust anybody else to be her proxy. These proxies
get together with their "assets" (delegated votes) and
choose a winner by use of some version of Robert's Rules of
Order.
Which criteria are satisfied by this method? Does Gibbard
Satthethwaite have anything to say about it? How about
Arrow? For that matter does first past the post plurality
satisfy the IIAC? (No more or less than Approval in reality.)
Let's talk about Gibbard-Satterthwaite. Is there any
incentive for a person to delegate as proxy someone other
than her favorite?
If we are talking representative democracy, then why would
you want to delegate your vote to candidate B when candidate
A was the one you trusted most to represent you in making
important decisions once in office?
All of the "problems" with the method are essentially
externalized to the deliberations governed by"Robert's Rules
of Order" in the smoke filled room.
Gibbard-Satterthwaite is taken to say that it is impossible
to obtain sincere preferences or sincere utilities from
voters in the context of full information (or disinformation)
elections. Yet it turns out to be relatively easy; you just
need to separate the ballot into two parts. The first part
requires strategic voting to pick the two alternatives as
finalists. The second part is used solely to choose between
these two options. (In the case of cardinal ballots the
finalists are lotteries.) A version of the uncertainty
principle obtains here: if you use the sincere ballots for
any other instrumental purpose than to choose between the two
finalists, then you almost certainly destroy their sincerity.
However there would be no problem comparing tthe sincere part
with the strategical part to get statistics about voters'
willingness to vote insincerely in choosing the finalists.
Another avenue that has been barely explored is the use of
chance to incentivize consensus when there is a potential for it.
For example, suppose that preferences are
60 A>C>>>>B
40 B>C>>>>A
Under approval voting the A faction has a strong incentive to
downgrade C and vote 60 A>>>>>C>B making A the (insincere)
approval winner as Gibbard-satterthwaite would predict.
However, if the rules said that in the absence of a full
consensus approval winner, the winner would be chosen by
random ballot, then (assuming rational voters voting in their
own interest) C would be the sure outcome; no rational voter
in either faction would prefer random ballot expectations
over a sure deal on C.
Jobst Heitzig is the pioneer in this area.
In sum, Arrow, et.al <http://et.al>. should not constitute a
nail in the coffin of creative progress in Election Methods.
IMHO that is an important message we need to send if we want
to attract new talent.
Forest
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