[EM] RCV in SF Mayoral election
Brian Olson
bql at bolson.org
Sun Jun 10 06:46:44 PDT 2018
I processed the latest data (2018-06-09) and posted the results of the SF
Mayor election using a few algorithms:
https://bolson.org/~bolson/2018/SF_Mayor_20180605.html
The Condorcet win is now 97436 to 91740 for Leno over Breed.
The IRV final round is still just 94783 to 94393.
I'm using my software posted at https://github.com/brianolson/voteutil
commands (needs maven installed for compiling Java, and needs Python3):
curl -O
http://www.sfelections.org/results/20180605/data/20180609/20180609_ballotimage.txt
curl -O
http://www.sfelections.org/results/20180605/data/20180609/20180609_masterlookup.txt
(mkdir -p ~/psrc && cd ~/psrc && git clone
https://github.com/brianolson/voteutil.git && cd ~/psrc/voteutil/java &&
mvn package)
python3 ~/psrc/voteutil/python/rcvToNameEq.py -m 20180609_masterlookup.txt
-b 20180609_ballotimage.txt -o 20180609_%s.nameq
java -jar ~/psrc/voteutil/java/target/voteutil-1.0.0.jar --rankings
--full-html --explain -i 20180609_Mayor.nameq >/tmp/a.html
On Sat, Jun 9, 2018 at 9:33 PM, Greg Dennis <greg.dennis at voterchoicema.org>
wrote:
> I quickly looked at the vote data and saw that lots of ballots are
>> categorized as "Exhausted by Over Votes" and "Under Votes," but there is no
>> data indicating exactly how those ballots were marked, so we lack enough
>> information to be sure of final results.
>
>
> Actually, all the data you need is available from that page. The "Ballot
> Image" file will give you the full cast vote record of every individual
> ballot, and the "Master Lookup" is the legend that tells you what each
> number means. If you have trouble interpreting the numbers, just ping me!
>
>
> On Sat, Jun 9, 2018 at 4:36 PM, VoteFair <electionmethods at votefair.org>
> wrote:
>
>> On 6/9/2018 6:25 AM, Greg Dennis wrote:
>> > San Francisco always make the cast vote record public:
>> > https://sfelections.sfgov.org/june-5-2018-election-results-d
>> etailed-reports
>>
>> I quickly looked at the vote data and saw that lots of ballots are
>> categorized as "Exhausted by Over Votes" and "Under Votes," but there is no
>> data indicating exactly how those ballots were marked, so we lack enough
>> information to be sure of final results.
>>
>> Converting instant-runoff counts into pairwise counts might be (probably
>> is?) possible, but I don't have time to do that analysis.
>>
>> > The probability of IRV not elected the Condorcet winner appears to be
>> > exceedingly low in practice. We're up to about ~200 IRV elections
>> > conducted nationwide since 2004 and Burlington 2009 is the only
>> > case so far.
>>
>> Yes, circular ambiguity -- in which there is no Condorcet winner -- is
>> rare when the number of ballots exceeds a few hundred.
>>
>> > On Sat, Jun 9, 2018 at 2:07 AM, robert bristow-johnson
>> > <rbj at audioimagination.com <mailto:rbj at audioimagination.com>> wrote:
>> > the limitation to only three levels of ranking is a problem. if
>> > someone ranked all three levels and none of the candidates ranked
>> > were either London Breed nor Mark Leno, that voter was effectively
>> > "disenfranchised" by being unable to weigh in on the final choice of
>> > choosing the mayor.
>>
>> Based on a very quick guesstimate it looks like about 30 or so ballots
>> had this issue. Right?
>>
>> That's not a big number, but a fair counting method -- such as pairwise
>> counting -- would not have to discard any ballots.
>>
>> The bigger number is "under votes" and admittedly pairwise counting
>> cannot compensate for a voter saying "here is the only acceptable choice"
>> (or two choices in this case).
>>
>> It's great that these results are getting analyzed by people who do not
>> drink the FairVote kool-aid.
>>
>> In haste,
>> Richard Fobes
>> "The VoteFair guy"
>>
>>
>> On 6/9/2018 6:25 AM, Greg Dennis wrote:
>>
>>> San Francisco always make the cast vote record public:
>>> https://sfelections.sfgov.org/june-5-2018-election-results-d
>>> etailed-reports
>>>
>>> Based on the most recent analysis of these numbers that I saw, Leno was
>>> indeed the Condorcet winner, and if Breed were to beat Leno in the final
>>> round, she would then necessarily be the Condorcet winner. The
>>> probability of IRV not elected the Condorcet winner appears to be
>>> exceedingly low in practice. We're up to about ~200 IRV elections
>>> conducted nationwide since 2004 and Burlington 2009 is the only case so
>>> far.
>>>
>>> On Sat, Jun 9, 2018 at 2:07 AM, robert bristow-johnson
>>> <rbj at audioimagination.com <mailto:rbj at audioimagination.com>> wrote:
>>>
>>>
>>> Richard, a few points:
>>>
>>> the limitation to only three levels of ranking is a problem. if
>>> someone ranked all three levels and none of the candidates ranked
>>> were either London Breed nor Mark Leno, that voter was effectively
>>> "disenfranchised" by being unable to weigh in on the final choice of
>>> choosing the mayor. however, i think the news media made it clear
>>> that the race was really gonna be between Leno, Breed, and Kim, so
>>> these fringe voters might have a chance to insincerely mark either
>>> Leno or Breed as their 3rd choice and betray their *true* third
>>> choice and, in doing so, have an effect in the final round.
>>>
>>> ignoring the problem of only 3 ranking levels, it is not possible
>>> that London Breed is the Condorcet Winner (a.k.a. "pairwise
>>> champion"). it might be the case that Mark Leno or Jane Kim is the
>>> Condorcet Winner and if the latter is the case, this is another real
>>> indictment against STV or IRV as a method of tallying RCV. and your
>>> reverse namesake, FairVote, is partially (or mostly) to blame.
>>>
>>> i wonder if the City of SF has a file of all of the cast and scanned
>>> ballots and the full ranking for each. if so, and if they release
>>> it to the public, we can investigate if there is a Condorcet Winner
>>> and if that CW is or is not Mark Leno. this would be interesting.
>>>
>>> L8r,
>>>
>>>
>>>
>>> r b-j
>>>
>>>
>>>
>>> > On 6/8/2018 6:24 PM, Christopher Colosi wrote:
>>> > > ... She stated “This is the system we are working with. That’s
>>> > > a discussion we can have at a later time. For now, we’re stuck
>>> with it.”
>>> > > - insinuating it is not fair. I was quite bothered to have a Dem
>>> in a
>>> > > progressive city insinuate that first past the post is more
>>> fair. ...
>>> >
>>> > This remark does not imply support for first past the post (FPTP,
>>> a.k.a
>>> > plurality counting).
>>> >
>>> > There are other ways to count the preference marks on
>>> "ranked-choice"
>>> > ballots. In particular, pairwise counting could be used instead of
>>> > instant-runoff counting, and that is fairer than FPTP.
>>> >
>>> > > 1. May not elect majority candidate
>>> > > ...
>>> > > Is this common? This is
>>> > > probably an abnormally close race. Thoughts?
>>> >
>>> > I doubt the voters would regard this as a close race if they had
>>> been
>>> > able to fully rank all the choices. The 3-choice limitation is
>>> > simplistic, and complicates the counting.
>>> >
>>> > Pairwise counting does not result in any exhausted ballots.
>>> Unmarked
>>> > choices are an indication that the choices are equally disliked.
>>> And
>>> > multiple candidates being marked at the same preference level is
>>> also no
>>> > problem.
>>> >
>>> > In other words, the ballots contain enough information that they
>>> can be
>>> > counted in other ways, besides instant-runoff counting. Those
>>> alternate
>>> > counting methods could reveal a clearer outcome.
>>> >
>>> > In haste,
>>> > Richard Fobes
>>> >
>>> >
>>> > On 6/8/2018 6:24 PM, Christopher Colosi wrote:
>>> >> Curious to hear people’s thoughts on some issues.
>>> >>
>>> >> 1. May not elect majority candidate
>>> >> In SF, we restrict to 3 choices to simplify the process. As the
>>> vote
>>> >> currently stands, 144 votes separate the top two candidates
>>> (<0.1%) and
>>> >> over 16,000 ballots have been exhausted (all 3 choices
>>> eliminated).
>>> >> About 9% of voters have been removed from the pool. It is very
>>> possible
>>> >> that the result would have shifted if they had the opportunity to
>>> rank a
>>> >> 4th candidate, and therefore, it is possible that we won’t elect
>>> the
>>> >> person who truly represents the majority. Is this common? This is
>>> >> probably an abnormally close race. Thoughts?
>>> >>
>>> >> 2. What are your thoughts on London Breed’s response to being
>>> asked if
>>> >> RCV is fair? She stated “This is the system we are working with.
>>> That’s
>>> >> a discussion we can have at a later time. For now, we’re stuck
>>> with it.”
>>> >> - insinuating it is not fair. I was quite bothered to have a Dem
>>> in a
>>> >> progressive city insinuate that first past the post is more fair.
>>> It
>>> >> also felt divisive. If Leno wins, will her supporters feel that
>>> >> democracy prevailed, or that the election was stolen? She also
>>> presents
>>> >> herself as a minority candidate and it is my understanding that
>>> RCV
>>> >> gives minority candidates better chances and causes all
>>> candidates to be
>>> >> more likely to campaign to minority communities. Am I mistaken?
>>> Are
>>> >> there any legitimate arguments that FPTP can be more fair?
>>> Thoughts?
>>> >>
>>> >> Regards,
>>> >> —Chris
>>> >>
>>> >>
>>> >>
>>> >> ----
>>> >> Election-Methods mailing list - see http://electorama.com/em for
>>> list info
>>> >>
>>> > ----
>>> > Election-Methods mailing list - see http://electorama.com/em for
>>> list info
>>> >
>>>
>>> --
>>>
>>> r b-j rbj at audioimagination.com
>>> <mailto:rbj at audioimagination.com>
>>>
>>> "Imagination is more important than knowledge."
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> ----
>>> Election-Methods mailing list - see http://electorama.com/em for
>>> list info
>>>
>>>
>>>
>>>
>>> --
>>> *Greg Dennis, Ph.D. :: Policy Director*
>>> Voter Choice Massachusetts
>>>
>>> e :: greg.dennis at voterchoicema.org <mailto:greg.dennis at voterchoicema.org
>>> >
>>> p :: 617.863.0746 <tel:617.863.0746>
>>> w :: voterchoicema.org <http://voterchoicema.org/>
>>>
>>> :: Follow us on Facebook
>>> <https://www.facebook.com/voterchoicema> and Twitter
>>> <https://twitter.com/voterchoicema> ::
>>>
>>>
>>> ----
>>> Election-Methods mailing list - see http://electorama.com/em for list
>>> info
>>>
>>> ----
>> Election-Methods mailing list - see http://electorama.com/em for list
>> info
>>
>
> ----
> Election-Methods mailing list - see http://electorama.com/em for list info
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.electorama.com/pipermail/election-methods-electorama.com/attachments/20180610/23a75a21/attachment-0001.html>
More information about the Election-Methods
mailing list