[EM] Fw: Proportional multi-winner ranked voting methods - EPR

[steve bosworth]

________________________________
Re: Proportional multi-winner ranked voting methods vs. Evaluative PR (EPR)


Date: Fri, 24 Feb 2017 01:09:59 +0200
From: Juho Laatu <juho.laatu at gmail.com>
To: EM <election-methods at lists.electorama.com>
Subject: Re: [EM] Proportional multi-winner ranked voting methods -
        guidelines?
Message-ID: <4A6DBFF9-B2E2-4284-86CA-0F3E8ACAB241 at gmail.com>
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Today's Topics:   2. Re: Proportional multi-winner ranked voting methods -
      guidelines? (Juho Laatu)


Juho Laatu juho.laatu at gmail.com wrote:


I just note that it would be useful to have some numeric requirements available when the usefulness of different proportional voting methods is evaluated. Some useful numbers (and other requirements) could be the number of candidates per district (e.g. 200, maybe 30 for each party), number of seats per district (e.g. 30), number of districts (e.g. 15), variation in the size of the districts (e.g. from 3 to 30 seats), handling of "overflow" and "lost" votes (e.g. votes to small parties in a district that has only 3 seats), required accuracy of proportionality (e.g. droop or hare proportionality at national level, or separately at each district), requirement of equal treatment of parties that get their support from one district only vs. evenly from all districts, planned style and accepted complexity of the ballots or voting machines, ability to vote for individual candidates, ability to vote multiple individual candidates across party borderlines, accuracy of party internal proportionality, ability to vote for one's favourite party (e.g. vote to one candidate inherited by other candidates of the party).

Hi Juho,



With respect to each of your elements that I’ve underlined above, I see Evaluative Associational PR (EAPR) as offering the most democratically attractive method for electing a nation’s legislative assembly.  However, I would greatly appreciate your feedback, both with regard to this claim and on the following explanations.  What do you think?

 If you want a copy of my fully explained of EAPR  I will email it to you (stevebosworth at hotmail.com).  However, this post more briefly explains a simplified version of EAPR for electing the Council for a small city. I call this version Evaluative PR (EPR) because it does not include the feature in EAPR that entirely removes gerrymandering by using a special ‘primary’ to elect all the electoral ‘associations’ (geographically defined or not) which would nominate all the candidates to run in the national election.  In a relatively small city like Santa Cruz in which all 7 of the Councilmembers could be elected at large, such a ‘primary’ would probably be unnecessary.  This is because these useful ‘associations’ could easily form themselves spontaneously in the context of using EPR in a small city.


I’ll explain EPR in contrast to Single Transferrable Voting (STV, i.e. RCV for electing multi-winners).  I mention RCV (i.e. IRV) because FairVote is currently campaigning for Santa Cruz to adopt RCV for electing its Council.  Instead, EPR (& EAPR) uses a modification of Majority Judgment (MJ -- Belinski & Laraki, 2010).  I see MJ and EPR as better than RCV because ‘evaluating’ candidates’ ‘fitness’ for the office is more meaningful, discerning, and informative than merely ‘ranking’ them.  It also offers a lower incentive and less scope for voting dishonestly (manipulation, etc.).   At the same time, ‘grading’ candidates is easier to do than ‘ranking’ them.  In addition, EPR avoids the problem with RCV methods that they can require the elimination of some candidates who are preferred by more citizens before the count is finished.  With ERP, all the evaluations of all the candidates by all the voters continue to count until all the most valued candidates are discovered to be the winners.



EPR vs. RCV
Of course, RCV would be a great improvement on existing arrangements for electing a city council or any legislature. However, I hope to show that Evaluative Proportional Representation (EPR) would more efficiently and completely support all the values and objectives put forward in favor of RCV.

Again, one key disadvantage of RCV is that it can require some candidates who are preferred by more voters to be eliminated before the winners are discovered.  For example, if 100 citizens vote in the following way, RCV would make candidate C win.  B would be eliminated by RCV even though she is preferred by more citizens:  20 citizens’ 1st preference votes and by 80 citizens’ 2nd preference votes.  Candidate C is supported only by 40 1st preference votes and by 20 2nd preference votes.  Candidate A is supported only by a different group of 40 1st preference votes.  Still RCV elects C:

100 CITIZENS:

40 prefer A over B over C

40 prefer C over B

20 prefer B over C

Fortunately, there are other methods that do not suffer from this flaw, e.g.  Evaluative Proportional Representation (EPR) is based on Majority Judgment (MJ) thinking (Belinski & Laraki, 2010, MIT press).  MJ is for electing a single winner (e.g. a governor or a president).

Instead, of asking each voter to ‘rank’ as many of the candidates they might wish, MJ and EPR ask voters to ‘grade’ as many of the candidates they might wish, i.e. to grade each candidate’s suitability for the office as being either EXCELLENT, VERY GOOD, GOOD, ACCEPTABLE, POOR or as REJECTED.  Any candidate not explicitly graded is counted as having been REJECTED by that voter.   With MJ, the winning candidate is the one who has the ‘highest median-grade’, i.e. the candidate to whom at least a majority have awarded at least this highest grade.  If more than one candidate has the same highest median-grade, the winner is discovered by removing any grades equal in value to this grade (one-by-one) from each tied candidate’s total until only one of the previously tied candidates is found to retain the highest median-grade.  Like RCV, this guarantees that the winner will have been supported quantitatively at least by a majority of those voting.  However, the MJ winner is more likely to be of a higher quality because he or she has been expressly evaluated more highly than any of the other candidates.



Also, ‘grading’ is easier than ‘ranking’ and grading also has the advantage of prompting citizens to think about what qualities make a candidate ‘fit’ for the office.  Grades are more informative, ‘discerning’ and ‘meaningful’ than numbers.  In addition, unlike other methods, EPR enables each citizen to guarantee that her one vote will continue fully to count in the deliberations of the Council.

EPR EXPLAINED
Ideally, all 7 members of Santa Cruzes City Council should be elected at the same time, all running at-large.  During this election, each citizen would be asked to evaluate as many of the candidates as they might wish, i.e. giving each, one of the above ‘grades’.  Any candidate not marked by a voter would be counted as Rejected by that voter.  The first candidate to be elected would be the one, if any, who had received the highest number of Excellents above or at the threshold, i.e. at least 1/7 of all citizens who have voted.

To honor the principle of one-person-one-vote,

1)     if a voter has given more than one candidate the same relevant evaluation, her evaluation will be added only to the candidate whose total of evaluations would consequently be greater at that stage of the count than any of the other candidates she has given the same ‘grade’,

2)     all the evaluations given to other candidates by voters who have already helped to elect an earlier candidate would play no part in electing any later candidate, and

3)     each elected candidate would have a ‘weighted vote’ in the Council exactly equal to the number of citizens who had helped to elect them.

In this way, it will be seen that each EPR citizen can guarantee that her one vote will continue fully to count in the deliberations of the Council.  To avoid the possibility of any one Councilmember being in a position to dictate to the Council, any Member who might have received more than 20% of all the ‘weighted votes’ in the Council, must publicly and non-returnably transfer her ‘extra’ votes to the ‘weighted votes’’ of one or more of her trusted fellow Members.  This means that any majority decision within the Council would require the agreement of at least 3 of the 7 Councilmembers.
The second candidate to be elected would be the one, if any, who had received the next highest number of remaining Excellents above or equal to the threshold (1/7).  The next candidates to be chosen, one by one, would be the ones, if any, who had received the next highest number of remaining Excellents above or equal to the threshold.  These would compose the first group of candidates to be elected.

Similarly, the second group of candidates to be chosen, one by one, would be the ones, if any, who had received the highest number of evaluations as a result of also adding all the remaining Very Goods, then Goods (the third group), and then Acceptables (the fourth group).



If the total number of winners within these four groups proved to be less than the required 7, the fifth and final group would be composed of the remaining number of Councilmembers required to complete the 7, i.e. still those most highly evaluated candidates and receiving a number of evaluations closest to the above threshold.  Again, each Councilmember would have a ‘weighted vote’ in the Council exactly equal to the number of evaluations from citizens added to her total.

Finally, the vote of any citizen whose vote had not yet been counted toward the ‘weighted vote’ of an elected candidate as a result of any of the above counts would now be added if possible to the ‘weighted vote’ of the Councilmember to whom she had given at least an evaluation of Acceptable.  However, if a citizen’s vote still could not be added in this way to the ‘weighted vote’ of one of the candidates who has already been elected, EPR’s ballot allows a citizen to require the non-elected candidate to whom she had given her highest evaluation, to transfer her one vote to the ‘weighted vote’ of the Councilmember he believes is the one most qualified for the office.  In this way, unlike RCV, each citizen can guarantee that their one vote will continue fully to count in the deliberations of the Council through the Councilmember she probably values most highly – no citizen’s vote need be wasted.

Consequently, I now see ERP as democratically superior to all other known methods for electing a legislative body because:

 1. It prompts citizens firstly to consider what qualities that are ideally required of the office being sought.
 2. By allowing citizens to express the full range of their evaluations of as many of the candidates as they might wish, this makes the results of an EPR election likely to be more discerning and informative than those provided by any other method, including RCV (e.g. plurality or First-Past-The- Post (FPTP), APPROVAL, SCORE (RANGE), Condorcet (e.g. Maximize Affirmed Majorities (MAM), open or closed Part-List, or Mixed Member PR).
 3. Also, unlike other multi-winner methods, EPR allows each citizen to guarantee that his or her vote will continue fully to count quantitatively and qualitatively in the deliberations of their city council (or their elected state or national legislature when using EAPR).
 4. In addition to the above advantages, since ‘grading’ candidates is easier than ‘ranking’ them, this makes it more like that each voter will see EPR as more user-friendly than the ‘ranking’ methods.
 5. Unlike Ranked Choice Voting (RCV), EPR does not waste any citizens’ votes, nor eliminate any candidate before all the most valued winners have been discovered.
 6. As contrasted to all other methods except FPTP and Part-List, EPR provides a lower incentive or less scope for citizens to vote dishonestly (manipulatively, strategically, tactically, etc.).

What do you think?    I look forward to your questions and feedback.

Steve (stevebosworth at hotmail.com)




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