<div dir="ltr">Hi Rob,<div><br></div><div>Your proposal makes sense to me for elections with a certain amount of consensus. However, it would be prudent to ensure that your method can still yield a reasonable solution in the absence of clear consensus.</div><div><br></div><div>For example, say candidate A1 is the approval winner with 40%. There are no candidates in the Plurality Approval or Opposition Candidate pool.</div><div><br></div><div>My preference in such a situation would be to include </div><div><br></div><div>A1, the approval winner,</div><div>A2, the approval runner-up,</div><div>B, the approval winner after excluding all ballots that approve A1, and must have excluded approval strictly less than 40%.</div><div><br></div><div>If total approval for A1 and B is less than 75%, I would continue including the approval winner on ballots that exclude A1, B, and previous complementary opposition candidates, until the 75% threshold is met. In the example above, A1's approval plus B's excluded approval could very easily fall below 75%, so it would likely be necessary to include candidate C, the candidate whose approval is highest on ballots that do not approve of either A1 or B.</div><div><br></div><div>I think including A2 (even if A2 is different than B or C) is important because with less than 50%, there isn't a strong consensus on A1.</div><div><br></div><div>Unfortunately this method does require a recount, but you can get A1, A2 and B with just a single summable count (accumulating the pairwise array of votes for candidate i when candidate j is not approved), and in subsequent counts, that pairwise array can help find both C and D if necessary. </div></div><br><div class="gmail_quote"><div dir="ltr">On Sun, Dec 9, 2018 at 8:32 PM Rob Lanphier <<a href="mailto:robla@robla.net">robla@robla.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi everyone,<br>
<br>
I've made some progress on the Majority Approval Filter proposal,<br>
which (as of December 7) I've published as "Draft 3" on electowiki;<br>
<<a href="https://electowiki.org/wiki/MAF" rel="noreferrer" target="_blank">https://electowiki.org/wiki/MAF</a>><br>
<br>
The current draft is more verbose, but I hope that it's clearer and<br>
more straightforward than the last two drafts. I've also published a<br>
blog post introducing latest draft on my personal blog[1] and on<br>
Medium[2]<br>
[1]: <a href="https://blog.robla.net/2018/12/09/replacing-the-jungle-primary-december-edition/" rel="noreferrer" target="_blank">https://blog.robla.net/2018/12/09/replacing-the-jungle-primary-december-edition/</a><br>
[2]: <a href="https://medium.com/@robla/replacing-the-jungle-primary-december-edition-cf971801402c" rel="noreferrer" target="_blank">https://medium.com/@robla/replacing-the-jungle-primary-december-edition-cf971801402c</a><br>
<br>
Here's my simplified version of the explanation:<br>
1. Select the candidate who receives the highest approval rating<br>
2. Also add all candidates who receive greater than 50% approval<br>
3. Possibly add opposition candidates if doing so is necessary to<br>
ensure that at least 75% of the electorate has someone they hope to<br>
vote for in the general election. Limit the number of candidates who<br>
qualify with 40%-50% approval to be less than or equal to the number<br>
of candidates who qualify with 50%-75% approval.<br>
<br>
I realize there's some handwaving in this simplified version, so I'm<br>
including the full text of the important bits below.<br>
<br>
Thanks especially to Ted Stern, but also to everyone who replied on<br>
the "[EM] Approval-based replacement for jungle primary" thread. I<br>
greatly appreciate the later replies from Kristofer Munsterhjelm and<br>
Richard Fobes, and I owe you two more detailed and direct replies to<br>
their emails now that I've published Draft 3.<br>
<br>
Rob<br>
--------------<br>
Addendum - Full definition of Majority Approval Filter (Draft 3)<br>
Copied from <<a href="https://electowiki.org/wiki/MAF" rel="noreferrer" target="_blank">https://electowiki.org/wiki/MAF</a>>):<br>
<br>
### Goal ###<br>
<br>
A set of rules for holding a primary election with an Approval<br>
Voting-style ballot, providing motivation for all candidates to achieve<br>
the highest approval rating, and resulting in a general election Ballot<br>
Satisfaction Score of at least 75%. The "Ballot Satisfaction Score" is<br>
the percentage of the electorate which approves of at least one<br>
candidate on a given ballot.<br>
<br>
### Pools ###<br>
<br>
Candidates advancing to the general election must qualify for one of the<br>
following "Pools". Candidates that don't qualify for one of the Pools<br>
below are "Non-advanced Candidates". By default, all candidates are<br>
Non-advanced Candidates until they qualify for one of these Pools:<br>
<br>
- "Supermajority Candidate Pool" - all candidates who receive greater<br>
than 75% approval<br>
- "Plurality Candidate Pool" - all candidates who receive greater than<br>
50% approval, but do not qualify for the Supermajority Candidate<br>
Pool. If no candidate receives greater than 50% approval, this pool<br>
will contain the leading candidate, who may have less than 50%<br>
approval.<br>
- "Opposition Candidate Pool" - a subset of candidates who receive<br>
greater than 40% approval, but do not qualify for the Plurality<br>
Candidate Pool<br>
<br>
### Rules ###<br>
<br>
Sequential steps for filling the above Pools with qualified candidates:<br>
<br>
1. Select the candidate who receives the highest approval rating. This<br>
is the "Top Candidate" and automatically qualifies for the general<br>
election ballot by one of the following rules:<br>
- 1a. If the Top Candidate receives greater than 75% approval, add<br>
this candidate to the Supermajority Candidate Pool.<br>
- 1b. If the Top Candidate receives less than 75% approval, add<br>
this candidate to the Plurality Candidate Pool.<br>
2. Complete the Supermajority Candidate Pool and the Plurality<br>
Candidate Pool using the following rules:<br>
- 2a. Add any Non-advanced Candidates with greater than 75%<br>
approval to the Supermajority Candidate Pool<br>
- 2b. Add any Non-advanced Candidates with less than 75% approval,<br>
but greater than 50% approval to the Plurality Candidate Pool<br>
3. Evaluate the Ballot Satisfaction Score (defined above) using the<br>
following rules:<br>
- 3a. If the Ballot Satisfaction Score is greater than 75%,<br>
candidate selection is complete. Skip to step 5<br>
- 3b. If the Ballot Satisfaction Score is less than 75%, proceed<br>
to step 4.<br>
4. If there is one or more candidates in the Plurality Candidate Pool,<br>
attempt to add an equal number qualified candidates to the<br>
Opposition Candidate Pool, evaluating each Non-advanced Candidate<br>
using the following steps<br>
- 4a. Find the Non-advanced Candidate with the highest approval<br>
score.<br>
- If this candidate has less than 40% approval, no further<br>
candidates qualify to be added to the Opposition Candidate<br>
Pool. Proceed to step 5.<br>
- If this candidate has greater than 40% approval, add this<br>
candidate to the Opposition Candidate Pool, then proceed to<br>
step 4b.<br>
- 4b. Compare the size of the Plurality Candidate Pool and the<br>
Opposition Candidate Pool<br>
- If the Plurality Candidate Pool has more candidates than the<br>
Opposition Candidate Pool, skip back to step 3.<br>
- If the Opposition Candidate Pool contains an equal number of<br>
candidates to the Plurality Candidate Pool, proceed to<br>
step 5.<br>
5. Candidate selection is complete. Advance all candidates in the<br>
Supermajority Candidate Pool, the Plurality Candidate Pool, and the<br>
Opposition Candidate Pool to the general election.<br>
----<br>
Election-Methods mailing list - see <a href="http://electorama.com/em" rel="noreferrer" target="_blank">http://electorama.com/em</a> for list info<br>
</blockquote></div>