[EM] UC davis STV election data - not very useful, actually

Scott Ritchie scott at open-vote.org
Fri Nov 11 13:53:28 PST 2005

On Fri, 2005-11-11 at 16:09 -0500, Warren Smith wrote:
> http://davischoicevoting.org/index.php?page=asucd
> So far there have been 4 elections.
> Each is a multiwinner election (e.g. the latest was 8 winners and 23 candidates)
> apparently run with reweighted STV voting.
> Each has a report about it with lots of charts and graphs.
> Each has had between 2447 and 4068 voters.
> I do not understand why these elections are of interest to single-winner
> voting researchers.  Two reasons for my non-interest:
>  1. they are multiwiner elections.
>  2. Assuming one of these is an interesting election, we
> are unable to apply other voting methods or to see if the
> election exhibited non-monotonicity, etc, because UC Davis does NOT
> post the actual votes, only a statistical summary of them.
Sorry, I gave the wrong link.  I can dig up the raw data somewhere.  We
also have a presidential election that is single winner IRV, I thought
the data was included in that set as well.  If you want it, I'll go get
it, but if you don't I'll just give up.

> This is the usual policy in IRV/STV elections, and it is apparently done
> intentionally to prevent anybody from ever knowing that the election
> was non-monotonic.  I.e. secrecy ==> nobody can prove there was a problem ==>
> everybody is "happy".
Never attribute to maliciousness what can properly be attributed to
laziness.  There is no massive conspiracy here to hide the voting data
from the student population, in part since the only people who would
understand the data are the people who brought us the voting system in
the first place.  Also note that it is an NP-complete problem to figure
out if the election was non-monotonic from the voting data in the first

> A less-cynical interpretation is simply that they do not want to post the votes,
> too voluminous data.  But Debian isn't afraid to show the world their votes.
> And certainly it is no big deal memory-wise to post 4000 votes.  UC Davis's
> posting of just one photographic image far exceeds the memory needed to post
> all the votes in all these elections combined.

That's not the UCD web site you're looking at - it's the
davischoicevoting site.  The elections.ucdavis.edu website is down at
the moment while they prepare for the coming vote next week, I'll see to
it that we get full data then.

> Also, the cynic will note that Davis refuses to report the number of invalid ballots,
> presumably also an attempt to cover up problems.  (In San Francisco 2004, the invalid
> "spoiled ballot" rate for IRV voting was 7 times their rate for plurality voting.)
No, it's because it's literally impossible to submit an invalid ballot.
We use a computerized internet voting system for these elections, and
the software prevents spoiled ballots.

> Anyhow, thanks to this non-posting of their votes, the UC Davis data is NOT
> useful to election researchers, but it might be if they actually did post the votes.
> Also, there is some interesting data in the summary reports they do post
> (e.g. about voter behavior).
If we want to talk about voter and candidate behavior, I have a lot of
firsthand information about how elections have changed since the
adoption of STV and ranked balloting vs block voting.  Pretty much what
you'd expect from a change to proportional representation with STV: more
turnout, more individualistic behavior from candidates promoting
themselves, more independent candidates, parties running different
numbers of candidates than there are seats (more and less in various
cases), etc.

Most interesting to us, of course, is strategic voting behavior.  Simply
put, given that candidates have a real absence of information about how
a very large chunk of the electorate will order their ballot, there
isn't much opportunity to exploit the non-monotonicity or encourage
their supporters to do so.  So, instead, candidates campaign on what
seems like an honest strategy: asking voters to rank them first, and
place their second choices after them, and so on.  Strategic voting
simply doesn't come up in the politics, since it's so hard to coordinate
and figure out, and the potential returns from doing so are far less
than standard campaigning.  Whether voters follow their instructions,
come up with their own rankings, or vote strategically (and don't tell
anyone about it) is still an open question.

Scott Ritchie

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