[EM] [CES #15255] Re: PAR: nearly-equivalent rules

[Jameson Quinn]

Yet another revision of the rules. This one fixes it so that, if no
candidates pass both thresholds, "accept" votes count.


Prefer Accept Reject (PAR) voting works as follows:

   1. *Voters Prefer, Accept, or Reject each candidate.* On ballots which
   don't explicitly use "Reject", blanks count as "Reject"; otherwise, blanks
   count as "Accept".
   2. *Of the candidates that are both "viable"* (at least 25% Prefer) *and
   "acceptable"* (no more than 50% reject), *the one with most "Prefer"s is
   called the leader.*
   3. Each "Prefer" is worth 1 point. For viable candidates, each "Accept"
   on a ballot which doesn't prefer the leader is also worth 1 point. *Most
   points wins.*


If I could do it without it sounding too complicated, I'd make it so that
explicit "accept" votes can count for non-viable candidates. But I don't
think it's worth even the minor extra complication it would take to explain
that.

Note that changing the above system so that it passes FBC requires only
giving a "prefer for the purposes of step 3, but count step 2 as if I
rejected" option.

I think this system is pretty great in outcomes; and that, while it's
certainly not the simplest method, it's not too complex.

2016-11-12 23:33 GMT-05:00 Jameson Quinn <jameson.quinn at gmail.com>:

>
>
> 2016-11-12 17:45 GMT-05:00 Neal McBurnett <nealmcb at gmail.com>:
>
>> I haven't been paying that much attention.  But this definition doesn't
>> define what this means "a rival is explicitly rejected".  Is "rejected" the
>> opposite of "viable"?  Or does it mean that no other voter cast any
>> "reject" vote for any other candidate?  Or ???
>>
>
> If candidates are ABCD, a ballot that prefers A and leaves the rest blank
> counts as rejecting BCD, but one that prefers A and rejects B and leaves
> the rest blank counts as accepting CD.
>
>
>
>> So if I have an "accept" on a ballot that doesn't "prefer" the leader,
>> that means 0 points?
>> Since votes depend on how other votes are interpreted and who the leader
>> is, is the tally guaranteed to be attracted to a single stable equilibrium
>> tally?
>>
>> Thanks,
>>
>> -Neal
>>
>> On Sat, Nov 12, 2016 at 05:27:53PM -0500, Jameson Quinn wrote:
>> > I think this is the best phrasing I've come up with so far for PAR. I
>> think it's not exactly equivalent to the definitions I've
>> > given before, but it is close enough to meet all the same properties
>> and give the same result in any basic scenario type.
>> >
>> > Prefer Accept Reject (PAR) voting works as follows:
>> >
>> >  1. Voters can Prefer, Accept, or Reject each candidate. Blanks count
>> as "Reject" if no rival is explicitly rejected; otherwise,
>> >     blank is "Accept".
>> >  2. Candidates with at least 25% Prefer, and no more than 50% reject,
>> are "viable". The most-preferred viable candidate (if any) is
>> >     the leader.
>> >  3. Each "prefer" is worth 1 point. For viable candidates, each
>> "accept" on a ballot which doesn't prefer the leader is also worth
>> >     1 point. Most points wins.
>> >
>> >
>> > 2016-11-12 13:47 GMT-05:00 Jameson Quinn <jameson.quinn at gmail.com>:
>> >
>> >     Thinking about PAR and the electoral college, I realized that there
>> is a different way to state the PAR rules:
>> >
>> >      1. Voters can Prefer, Accept, or Reject each candidate. Default is
>> "Reject" for voters who do not explicitly reject any
>> >         candidates, and "Accept" otherwise.
>> >      2. A candidate is "viable" if they are rejected by under 50%.
>> >      3. Each ballot gives 1 point to each candidate it prefers. Ballots
>> which prefer no viable candidates also give 1 point to each
>> >         candidate they accept, so long as that candidate is preferred
>> by at least 25%.
>> >      4. Now find the viable candidate with the most points, if any, and
>> redo step 3 from scratch as if only that candidate were
>> >         viable.
>> >      5. The winner is the candidate with the most points.
>> >
>> >     This could potentially differ from PAR in that it waits slightly
>> longer to "reveal" the preferences of candidates with under
>> >     25% preferences. In practice, I doubt this would typically make any
>> difference.
>> >
>> >     The procedure above is more complicated than PAR's, but the
>> advantage is that it produces counts which include the disqualified
>> >     candidates, and thus is suitable for combining with totals from
>> non-PAR systems such as approval, plurality, or
>> >     "pre-elimination totals" from IRV.
>> >
>> >
>> > --
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>
>
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