Re: [EM] Some chance for consensus revisited: Most simple solution

2009-02-02 Thread Jobst Heitzig
Hi Raph,

 The odds of it actually working are pretty low.  For it to work, all
 voters must be aware that C is a valid compromise.

Sure, that's the flipside of it being so ultimately simple. The easiest way to 
safeguard against a small number of non-cooperative voters would be to require 
only, say, 90% of the consensus ballots to have the same option ticked in 
order for that option to be elected. I guess that's what you mean by threshold:

 In practice, there needs to be a reasonable threshold.  There is
 always going to be a need to balance tyranny of the (N%) majority
 against the hold-out problem.

Even with a 90% threshold, a tyranny of a 90% majority can be avoided, but this 
requires another slight modification: Instead of on two separate ballots, every 
voter marks her favourite and consensus options on one ballot using markers 1 
and 2. Then a ballot is drawn at random. If at least 90% of all ballots mark 
the same option 2 as this drawn ballot does, then that option wins. Otherwise 
the option marked 1 on the drawn ballot wins. In this way, a bullet-voting 
faction of, say, 5%, allocates at least 5% winning probability to their 
favourite (as required by my interpretation of democratic method).

Yours, Jobst

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[EM] Some chance for consensus revisited: Most simple solution

2009-02-01 Thread Jobst Heitzig
Dear folks,

I want to describe the most simple solution to the problem of how to
make sure option C is elected in the following situation:

   a%  having true utilities  A(100)  C(alpha)  B(0),
   b%  having true utilities  B(100)  C(beta)   A(0).

with  a+b=100  and  a*alpha + b*beta  max(a,b)*100.
(The latter condition means C has the largest total utility.)

The ultimately most simple solution to this problem seems to be this method:


Simple Efficient Consensus (SEC):
=

1. Each voter casts two plurality-style ballots:
   A consensus ballot which she puts into the consensus urn,
   and a favourite ballot put into the favourites urn.

2. If all ballots in the consensus urn have the same option ticked,
   that option wins.

3. Otherwise, a ballot drawn at random from the favourites urn
   decides.


Please share your thoughts on this!

Yours, Jobst



Jobst Heitzig schrieb:
 Hello folks,
 
 I know I have to write another concise exposition to the recent
 non-deterministic methods I promote, in particular FAWRB and D2MAC.
 
 Let me do this from another angle than before: from the angly of
 reaching consensus. We will see how chance processes can
 help overcome the flaws of consensus decision making.
 
 I will sketch a number of methods, give some pros and cons, starting
 with consensus decision making.
 
 Contents:
 1. Consensus decision making
 2. Consensus or Random Ballot
 3. Approved-by-all or Random Ballot
 4. Favourite or Approval Winner Random Ballot: 2-ballot-FAWRB
 5. Calibrated FAWRB
 6. 4-slot-FAWRB
 7. 5-slot-FAWRB
 
 
 
 1. Consensus decision making
 
 The group gathers together and tries to find an option which everyone
 can agree with. If they fail (within some given timeframe, say), the
 status quo option prevails.
 
 Pros: Ideally, this method takes everybody's preferences into account,
 whether the person is in a majority or a minority.
 
 Cons: (a) In practice, those who favour the status quo have 100% power
 since they can simply block any consensus. (b) Also, there are problems
 with different degrees of eloquence and with all kinds of group-think.
 (c) Finally, the method is time-consuming, and hardly applicable in
 large groups or when secrecy is desired.
 
 
 Let us address problem (a) first by replacing the status quo with a
 Random Ballot lottery:
 
 
 2. Consensus or Random Ballot
 -
 Everybody writes her favourite option on a ballot and gives it into an
 urn. The ballots are counted and put back into the urn. The number of
 ballots for each option is written onto a board. The group then tries to
 find an option which everyone can agree with. If they fail within some
 given timeframe, one ballot is drawn at random from the urn and the
 option on that ballot wins.
 
 Pros: Since the status quo has no longer a special meanining in the
 process, its supporters cannot get it by simply blocking any consensus -
 they would only get the Random Ballot result then. If there is exactly
 one compromise which everybody likes better than the Random Ballot
 lottery, they will all agree to that option and thus reach a good
 consensus.
 
 Cons: Problems (b) and (c) from above remain. (d) Moreover, it is not
 clear whether the group will reach a consensus when there are more than
 one compromise options which everybody likes better than the Random
 Ballot lottery. (e) A single voter can still block the consensus, so the
 method is not very stable yet.
 
 
 Next, we will address issues (b), (c) and (d) by introducing an approval
 component:
 
 
 3. Approved-by-all or Random Ballot
 ---
 Each voter marks one option as favourite and any number of options as
 also approved on her ballot. If some option is marked either favourite
 or also approved on all ballots, that option is considered the
 consensus and wins. Otherwise, one ballot is drawn at random and the
 option marked favourite on that ballot wins.
 
 Pros: This is quick, secret, scales well, and reduces problems related
 to group-think. A voter has still full control over an equal share of
 the winning probability by bullet-voting (=not mark any options as also
 approved).
 
 Cons: (b') Because of group-think, some voters might abstain from using
 their bullet-vote power and also approve of options they consider
 well-supported even when they personally don't like them better than the
 Random Ballot lottery. Also, (e) from above remains a problem, in
 particular it is not very likely in larger groups that some options is
 really approved by everyone.
 
 
 Now comes the hardest part: Solving problems (b') and (e) by no longer
 requiring full approval in order to make it possible to reach almost
 unanimous consensus when full consensus is not possible. In doing so,
 we must make sure not to give a subgroup of the electorate full power,
 so that they can simply overrule the rest. Instead, we must make the
 modification so 

Re: [EM] Some chance for consensus revisited: Most simple solution

2009-02-01 Thread Jobst Heitzig
You're absolutely right, Juho -- I modified the condition a number of
times and didn't realize the last version did not imply both factions
prefer C to Random Ballot.

The correct set of situations for which SEC is a solution is
characterized by both factions prefering C to Random Ballot. The latter
is in particular true when alpha=beta and C has the largest total utility.

Sorry for the mistake,
Jobst

Juho Laatu schrieb:
 Makes sense but doesn't this allow also
 
 50: A(100)  C(40)  B(0)
 50: B(100)  C(70)  A(0)
 
 where 50*40 + 50*70  max(50,50)*100
 
 but the A supporters may prefer random ballot from the favourites urn to the 
 possible consensus result (C) and therefore vote (e.g.) for A in their 
 consensus ballot.
 
 Juho
 
 
 
 --- On Sun, 1/2/09, Jobst Heitzig heitzi...@web.de wrote:
 
 From: Jobst Heitzig heitzi...@web.de
 Subject: [EM] Some chance for consensus revisited: Most simple solution
 To: election-methods@lists.electorama.com
 Date: Sunday, 1 February, 2009, 11:02 PM
 Dear folks,

 I want to describe the most simple solution to the problem
 of how to
 make sure option C is elected in the following situation:

a%  having true utilities  A(100)  C(alpha) 
 B(0),
b%  having true utilities  B(100)  C(beta)  
 A(0).

 with  a+b=100  and  a*alpha + b*beta  max(a,b)*100.
 (The latter condition means C has the largest total
 utility.)

 The ultimately most simple solution to this problem seems
 to be this method:


 Simple Efficient Consensus (SEC):
 =

 1. Each voter casts two plurality-style ballots:
A consensus ballot which she puts into the
 consensus urn,
and a favourite ballot put into the
 favourites urn.

 2. If all ballots in the consensus urn have the
 same option ticked,
that option wins.

 3. Otherwise, a ballot drawn at random from the
 favourites urn
decides.


 Please share your thoughts on this!

 Yours, Jobst



 Jobst Heitzig schrieb:
 Hello folks,

 I know I have to write another concise exposition to
 the recent
 non-deterministic methods I promote, in particular
 FAWRB and D2MAC.
 Let me do this from another angle than before: from
 the angly of
 reaching consensus. We will see how chance processes
 can
 help overcome the flaws of consensus decision making.

 I will sketch a number of methods, give some pros and
 cons, starting
 with consensus decision making.

 Contents:
 1. Consensus decision making
 2. Consensus or Random Ballot
 3. Approved-by-all or Random Ballot
 4. Favourite or Approval Winner Random Ballot:
 2-ballot-FAWRB
 5. Calibrated FAWRB
 6. 4-slot-FAWRB
 7. 5-slot-FAWRB



 1. Consensus decision making
 
 The group gathers together and tries to find an option
 which everyone
 can agree with. If they fail (within some given
 timeframe, say), the
 status quo option prevails.

 Pros: Ideally, this method takes everybody's
 preferences into account,
 whether the person is in a majority or a minority.

 Cons: (a) In practice, those who favour the status quo
 have 100% power
 since they can simply block any consensus. (b) Also,
 there are problems
 with different degrees of eloquence and with all kinds
 of group-think.
 (c) Finally, the method is time-consuming, and hardly
 applicable in
 large groups or when secrecy is desired.


 Let us address problem (a) first by replacing the
 status quo with a
 Random Ballot lottery:


 2. Consensus or Random Ballot
 -
 Everybody writes her favourite option on a ballot and
 gives it into an
 urn. The ballots are counted and put back into the
 urn. The number of
 ballots for each option is written onto a board. The
 group then tries to
 find an option which everyone can agree with. If they
 fail within some
 given timeframe, one ballot is drawn at random from
 the urn and the
 option on that ballot wins.

 Pros: Since the status quo has no longer a special
 meanining in the
 process, its supporters cannot get it by simply
 blocking any consensus -
 they would only get the Random Ballot result then. If
 there is exactly
 one compromise which everybody likes better than the
 Random Ballot
 lottery, they will all agree to that option and thus
 reach a good
 consensus.

 Cons: Problems (b) and (c) from above remain. (d)
 Moreover, it is not
 clear whether the group will reach a consensus when
 there are more than
 one compromise options which everybody likes better
 than the Random
 Ballot lottery. (e) A single voter can still block the
 consensus, so the
 method is not very stable yet.


 Next, we will address issues (b), (c) and (d) by
 introducing an approval
 component:


 3. Approved-by-all or Random Ballot
 ---
 Each voter marks one option as favourite
 and any number of options as
 also approved on her ballot. If some
 option is marked either favourite
 or also approved on all ballots, that option is
 considered the
 consensus and wins. Otherwise, one ballot
 is drawn at random