Approval

Craig Carey research at ijs.co.nz
Mon Feb 28 12:55:03 PST 2000




At 05:17 29.02.00 , MIKE OSSIPOFF wrote:
>
>
>
>>Are people writing to this list advocating some "Approval Vote" method?.
>
>Yes. But it it isn't a question of some Approval method; there's
>one method called Approval: Same as Plurality except that each
>voter may give one vote each to any candidate(s). As with
>Plurality, the candidate with the most votes wins.
>
>>Isn't it one of the very worst methods around?.
>
>No.

[from below]
>Who told you that Approval was one of the worst??

----------------
At 10:20 28.02.00 , Bart Ingles wrote:
>
>Craig Carey wrote:
>> Are people writing to this list advocating some "Approval Vote" method?.
>> Isn't it one of the very worst methods around?.
>
>In whose estimation?  Prof. Saari?
>
Was that part of a quite public dispute?. I suppose Borda is better
 since the Approval method is a Borda method but with the weights
 (1, 1, 1, ...) for each preference.

----------------

http://bcn.boulder.co.us/government/approvalvote/center.html


The power a voter has will be a hump shaped curve with the
 voters having no power if the number of votes they cast is zero
 or if the number votes they cast is equal to the number of
 candidates.

Power
 +
 +                             +     +     +
 +                       +                       +
 +                 +
 +           +
 +     +
 +-----+-----+-----+-----+-----+-----+-----+-----+-----+---->
 0     1     2     3     4     5     6     7  Number of Votes

Voters are expected to want to go into a voting booth and while
 in there they want to (a) retain or (b) change the government.
 They do not want to consider the latest, IF ANY, on hump shaped
 curves.

It is not a method that tries particularly hard to elect their
 first preference.

Subsequent preferences act against earlier preferences.

Example: Suppose that in a election using a preferential vote,
 a voter would have voted A>B>C>D. The voter very much (or 
 infinitely) prefers A to B to C to D.
 Suppose the method was electing two winners.
 Approval vote isn't a preferential method.
 This voter is either important with 3 votes or the there are
 3 voters.

 In the voting booth the voter can't easily tell if D should
 be voted for. They may be >7 candidates so the voter may
 imagine that voting for D gives him/her more power.
 In this example voting for D is to the voter's disadvantage:

             A     B     C     D
3 Voters:    3     3     3     3
  Others:    6     7     8     9
   Total:    9     9    11    12
Winners  = {C,D}

             A     B     C     D
3 Voters:    3     3     3
  Others:    6     7     8     9
   Total:    9    10    11     9
Winners  = {B,C}

Mr Brams or whomever might call it a simple method. I can't recall
 who declared that the Approval method was simple. Perhaps it might
 be called "a simple method for a simple people" (after carefully
 excluding unavoidable comments from senators and congressmen who
 probably haven't studied the method for long enough). But voters
 may think it is more a method that demands that they be a nation
 of Einsteins. The information they need to decide whether a voter
 should list all of what they want or just a fraction of the
 candidates they want elected, is completely unavailable to them
 when they are voting, and even if accurate polls from the
 previous day were available, it may be difficult to interpret
 because the problems with the Approval Vote occur when candidates
 have similar support.

It would need to be shown that voters do actually know whether
 they prefer candidates over other candidates rather than knowing
 that they are indifferent to a group of three (lest a fourth wins
 and makes the 2nd lose), or is it all four? (in those cases where
 the three would win anyway).

What are the names of the theorists that would want to replicate
 those sort of considerations over groups containing at thirty
 thousand people?.

Surely it is better to stay with a genuinely simple method like
 First Past the Post, or else use a well designed preferential
 voting method like STV?


>
>Approval is one of the very best methods around. Only Condorcet

A false statement there.

>& Bucklin are better, by defensive strategy standards. That
>makes Approval the 3rd best method. Bucklin isn't being proposed
>now by anyone, and so it can be said that Approval is the
>2nd best current proposal, by those standards. By "Bucklin",
>I mean the class of methods that includes Bucklin and the various
>ordered-Bucklins, including Davison's RWE. By "Condorcet", I mean
>the whole class of methods that qualify as Condorcet versions.
>
>Who told you that Approval was one of the worst??

----------------
At 10:20 28.02.00 , Bart Ingles wrote:
>
>Craig Carey wrote:
>> Are people writing to this list advocating some "Approval Vote" method?.
>> Isn't it one of the very worst methods around?.
>
>In whose estimation?  Prof. Saari?
>
Was that part of a quite public dispute?. I suppose Borda is better
 since the Approval method is a Borda method but with the weights
 (1, 1, 1, ...) for each preference.

----------------

I don't have definitions for WDSC, NDDC, Bucklin. They could be
 messages but I am aiming just to sustain an interest long enough
 to get this message out.


>
>Approval, along with Condorcet & Bucklin, is one of the few methods
>that meet WDSC, the Weak Defensive Strategy Criterion, which
>is in the process of changing its name to NonDrastic Defense
>Criterion (NDDC):
>
>If a majority of all the voters prefer A to B, then they should
>have a way of voting that will ensure that B can't win, without
>any member of that majority voting a less-liked candidate over
>a more-liked candidate.
>
>I've mentioned the methods that meet NDDC. Methods that fail
>it include IRV (aka The Alternative Vote, Preferential Voting,
>Majority Preferential Voting, etc.); BeatsAll//IRV; Schulze(Margins),
>Tideman(Margins); Borda;...and pretty much any other method.
>
>***
>
>These 2 criteria are met by Approval, and by no other method:
>
>Favorite-Betrayal Criterion (FBC):
>
>By voting a less-liked candidate over his favorite, a voter should
>never gain an outcome that he likes better than any outcome that
>he could get without voting a less-liked candidate over his
>favorite.
>

I suppose the words "over his favorite" mean the number of votes
 cast remains constant. That makes the criteria is significantly
 less value.

>***
>
>Strong Adverse Results Criterion (SARC):
>
>If a group of voters share the same preferences, and if they
>all vote the same way, in a way that could, with some configuration
>of the other people's votes, produce an outcome better than any
>outcome that they could get in any other way, then the fact that
>they showed up & voted in that way should never cause their
>favorite to lose, or cause their last choice to win, if that
>wouldn't have happened had they not showed up & voted.

So it may satisfy SARC, but the Approval vote shows bad properties
 when voters change the number of votes they use.

>***
>
>FBC & SARC are met by no method except for Approval.
>
>***
>
>As I said, I personally prefer Condorcet's exclusive criterion
>compliances. Or, putting it in more direct terms-- Approval
>makes good use of previous elections, and will quickly home in

[Makes no use of previous election's data]

>on the median candidate or party, but Condorcet will usually
>go directly to the target in its 1st election. Also, I
>like the luxury of being able to rank, with respect to each other,
>the candidates whom I'd vote for in Approval, as I can do in
>Condorcet or Bucklin. Additionally, with Condorcet, if the

A problem with the Approval Vote is that it creates extremely
 difficult stragic voting mathematical problems for individual
 voters. They do not have the data or the time to allow them
 to run computer simulations just in a hopeless aim of trying
 to have their vote have no less influence than their
 neighbours.

It is beyond imagination that the Democrats and the Republicans
 would not be running their own simulations, etc. They have the
 intelligence and the money: they jsut don't have the Approval
 Voting method.


...
>***
>
>Far from being one of the worst, Approval is the 2nd best
>voting system proposal. Something to consider especially if
>you find that it's difficult or decades-time-consuming getting
>a good rank method adopted. I'm not saying it will be, but
>if so there's an interim reform that would bring immediate
>improvement.

The last 2 sentences are the only reason I can think of for
 considering adopting the Approval Vote.

Electorates may be better off with multiwinner First Past the
 Post. At least FPTP/FPP is a true preferential method.
 Even Borda (2 versions perhaps) is a better, but by how much
 is unclear. I believe FPTP IS a better method than the Approval
 Voting method.

How has the Approval Voting method evolved over the last decade
 or years?.

I was unsure about Mr D. G. Saari criticisng [when was that?] the
 Approval Vote because of that gentleman's limited commenting
 on the Borda method, but Borda is a better method [check] and it
 can be since the two are oiut of the same class [different
 weights].

---------------------------------------------------------------

To the list owner, ... and on behalf of others, I have a
 question.

Of all subscribed e-mail addresses, what are the frequencies of
 each 2 letter country domain?.







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