[EM] RCV in SF Mayoral election
Brian Olson
bql at bolson.org
Mon Jun 11 10:16:23 PDT 2018
I wrote Python code to parse the 'ballot image' and 'master lookup' files.
https://github.com/brianolson/voteutil/blob/master/python/rcvToNameEq.py
I have this exporting to www-cgi formatting like
Alice=1&Bob=2&Carol=3
On Mon, Jun 11, 2018 at 11:45 AM, Christopher Colosi <colosi at gmail.com>
wrote:
> How is the ballot image file laid out? It seems like a horrible choice
> for formatting. Is there any delimiter between ballots, or is this just
> one gigantic string of numbers?
>
> On Sun, Jun 10, 2018 at 10:42 PM robert bristow-johnson <
> rbj at audioimagination.com> wrote:
>
>>
>>
>>
>>
>> boy this is embarrassing. i didn't realize they were still counting and
>> that the lead has changed. looks like London Breed is ahead and will
>> likely win the STV contest.
>>
>> and, from Brian's initial analysis, it doesn't look like the Condorcet
>> Winner will be different from the STV winner. so no Burlington 2009
>> situation.
>>
>> L8r,
>>
>> r b-j
>>
>>
>>
>> ---------------------------- Original Message ----------------------------
>> Subject: Re: [EM] RCV in SF Mayoral election
>>
>> From: "robert bristow-johnson" <rbj at audioimagination.com>
>> Date: Sun, June 10, 2018 10:23 pm
>> To: "EM" <election-methods at lists.electorama.com>
>> Cc: "Brian Olson" <bql at bolson.org>
>> ------------------------------------------------------------
>> --------------
>>
>>
>>
>> >
>> >
>> >
>> > Thank you Brian for doing this. Looks like Leno is the legit winner
>> and STV and Condorcet agree.
>> > However, the Leno-Breed pair wise tally in the defeat matrix should be
>> exactly the same as the STV final round result. So something is wrong
>> somewhere.
>> > But thanks for doing this. I was about to code up a MATLAB program to
>> parse and count this thing.
>> >
>>
>> > --r b-j rbj at audioimagination.com
>>
>>
>> > "Imagination is more important than knowledge."
>> >
>> >
>> >
>> >
>> > -------- Original message --------
>> >
>> From: Brian Olson <bql at bolson.org>
>> > Date: 6/10/2018 7:46 AM (GMT-08:00)
>> > To: EM <election-methods at lists.electorama.com>
>> > Subject: Re: [EM] RCV in SF Mayoral election
>> >
>> > Ok, a few lines of Python poking the raw data shows I must have some
>> bug in my Condorcet implementation. Digging into that...
>> > On Sun, Jun 10, 2018 at 10:08 AM, Greg Dennis <
>> greg.dennis at voterchoicema.org> wrote:
>> > Brian, how is it possible that those differ? Since all the other
>> candidates are eliminated in the final round, shouldn't that necessarily be
>> the same as the pairwise contest between those two?
>> >
>> > On Sun, Jun 10, 2018, 9:46 AM Brian Olson <bql at bolson.org> wrote:
>> > 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.txtcurl -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.nameqjava -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-
>> detailed-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-
>> detailed-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@
>> 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
>> >
>> >
>> >
>> >
>> > ----
>> >
>> > Election-Methods mailing list - see http://electorama.com/em for list
>> info
>> >
>> >
>> >
>> >
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>> info
>> >
>>
>> --
>>
>> r b-j rbj at audioimagination.com
>>
>> "Imagination is more important than knowledge."
>>
>>
>>
>>
>>
>>
>>
>> ----
>> Election-Methods mailing list - see http://electorama.com/em for list
>> info
>>
>
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