Historic Moment for Ranked Voting in Davis, CA!

A Governance Task Force in Davis, California voted nearly unanimously to recommend Choice Voting for their city's elections.  Congratulations to that rockin' Davis ranked voting group (www.davischoicevoting.org)!  Here's a story about the Task Force recommendation.  The recommendation still needs to be approved by the Davis city council.  We wish Davis continued success towards fairer elections!

Comments

[Mike Ossipoff]

I agree that the best voting systems use rank-ballotiong. Regrettably, Instant Runoff (IRV) is not one of those best voting systems.

Though the best methods use rank balloting, the merit of a rank-balloting voting system depend entirely on how the rankings are counted.

It turns out that only a very few of the very best rank-methods are as good as the simple & modest Approval method:

Approval:

Voters may mark as many names on the the ballot as they want to. The candidate receiving the most marks wins.

[end of Approval definition]

A more familiar method that is strategically equivalent to Approval is "Cardinal Ratings" (CR). CR is the familiar points system, sometimes called "Range Voting":

Voters may give to any candidate(s) any number of points, within some pre-specified range. The candidate receiving the most points wins.

For instance, voters could be allowed to give to any candidate anywhere from 0 to 10 points, or from 0 to 100 points, or anywhere from -10 to 10 points, or anywhere from -100 to 100 points.

Approval itself is a version of CR. Approval is the simplest CR version, the 0,1 CR version in which a voter may give to any candidate either 0 or 1 point.

Being more familiar than Approval, the CR versions such as 0 to 10 or 0 to 100, or -10 to 10, or -100 to 100 would probably be the best public proposal for voting system reform.

As I said, only a very few of the very best rank-methods are as good as Approval and CR.

You can read about those at:

http://www.barnsdle.demon.co.uk/vote/sing.html

IRV has a number of problems that its advocates don't tell you about.

They boast that IRV gets rid of the lesser-of-2-evils problem, and that you can safely vote your favorite in 1st place. No, that's only true if your favorite is a sure loser, sure to be the first candidate eliminated. Otherwise your favorite could eliminate your needed compromise, and then lose to your last choice.

IRV fails the following criterion:

Participation:

Adding to the count one or more ballots that vote X over Y should never change the winner from X to Y.

[end of Participation definition]

Approval and CR pass Participation. Instant Runoff (IRV) fails Participation.

The rank methods that are better than Approval and CR are certain versions of Condorcet's method.

In particular, the "winning-votes" versions of Condorcet's method.

Condorcet was the 18th century French founder of voting theory. Here's the general definition of winning-votes Condorcet's method:

1. Voters may rank any number of candidates in order of preference. They may rank more than one candidate at the same rank position if they want to.

2. X "beats" Y if more voters rank X over Y than rank Y over X.

3. Any candidate who is unbeaten wins, and if there's any such candidate, the count ends.

4. Otherswise, one of several "circular tie solutions" is used.

5. For the purpose of those methods, a "defeat" is an instance of one candidate beating another.

6. For the purpose of those circular tie solutions, if X beats Y, the "strength" of that defeat is defined as the number of people who ranked X over Y.
[end of general definition of winning-votes Condorcet's method]

Here are two circular tie solutions:

Plain Condorcet (PC) is the literal interpretation of the circular tie solution described by Condorcet himself:

Plain Condorcet (PC):

Drop the weakest defeat. Repeat till a candidate isn't beaten. S/he wins.

[end of PC definition]

Sequential Dropping (SD):

Drop the weakest defeat that's in a cycle. Repeat till a candidate is unbeaten. S/he wins.

[end of SD definition]

These Condorcet methods meet criteria not met by other proposed methods, including Instant Runoff.

Here are some such criteria:

Weak Defensive Strategy Criterion (WDSC):

If a majority prefer X to Y, then they should have a way of voting that ensures that Y won't win, without any member of that majority voting a less-liked candidate over a more-liked one.

[end of WDSC definition]

All the Condorcet versions that I propose meet WDSC. Instant Runoff fails WDSC, and so does Plurality, the method currently in use.

Strategy-Free Criterion (SFC):

First a preliminary definition:

The Condorcet winner (CW) is a candidate who, when compared separately to each one of the others, is preferred to him/her by more voters than vice-versa.

[end of CW definition]

SFC:

If no one falsifies a preference, and if a majority prefer the CW to candidate Y, and vote sincerely, then Y shouldn't win.

[end of SFC definition]

What SFC means is that, when a method is used that complies with SFC, a majority, under the plausible premise conditions of SFC, has no need to do other than rank the candidates sincerely. They need no strategy under those conditions.

It's desirable for a group of voters to be completely free of need to do other than rank sincerely. SFC describes the conditions under which it's possible to make that guarantee, for methods that comply with SFC.

SFC's definition refers to voting sincerely, and so a definition of that is needed too:

A voter votes sincerely if s/he doeesn't falsify a preference, or fail to vote a preference that the balloting system in use would have allowed him/her to vote in addition to the preferences that s/he actually did vote.

[end of sincere voting definition]

A voter votes X over Y if s/he votes in such a way that if we count only his/her ballot, with all the candidates by X & Y deleted from it, X wins and Y doesn't win.

[end of definition of voting one candidate over another]

A voter falsifies a preference if s/he votes X over Y and prefers Y to X.

A voter votes a preference for X over Y if s/he prefers X to Y and votes X over Y.

[end of supporting definitions]

Favorite Betrayal Criterion (FBC):

In a given election, for any particular voter who has a unique favorite, and with a particular set of candidates, there should be no possible configuration of other people's votes such that that voter can get his/her best outcome only by voting someone over his/her favorite.

[end of FBC definition]

In other words, no one should ever need to vote someone over his favorite.

Approval & CR meet FBC, Participation, and WDSC.

PC and SD meets SFC and WDSC.

More methods and criteria can be read about at:

http://www.barnsdle.demon.co.uk/vote/sing.html

Let me know if there are any questions, comments, objections, or disagreements.

Mike Ossipoff

[James Green-Armytage]

Mike, this announcement was about "choice voting". Choice voting is a euphemism for STV proportional representation, not for IRV. Your salient criticism of IRV ("...you can safely vote your favorite in 1st place. No, that's only true if your favorite is a sure loser, sure to be the first candidate eliminated...") does not apply to STV-PR.

Amy, congratulations on your progress with STV. I wish you the best of luck.