[EM] Real Ballot Data & Analysis

[Eric Gorr]

I am sure others are aware of this data, but I just got my hands on 
it and spent some time analyzing it with single winner methods. 
Apparently in Dr. Tideman's research into voting methods, he was able 
to obtain many (86) ranked ballots from elections held in England.

I uploaded everything into the Files section of the group and it can 
be found at:

   http://tinyurl.com/2bmvw

I have included some PHP code to compute the IRV winner, executable 
as a shell script.

However, please do not trust my results just yet. I would really love 
it if someone could spend some time verifying my results and making 
sure my conversion of the ballots from the data Dr. Tideman provided 
to data I could more easily work with, paying closest or initial 
attention to A6, A13, A15, A26 and A81.

I was basically interested in looking at the single winners that 
Ranked Pairs(d-wv) and IRV would compute.

What I found is what I believe to be quite interesting. In nearly 6% 
of the cases, the IRV and RP winner(s) were different. The majority 
of cases had a Condorcet Winner.

Any comments? Any invalid or just plain wrong assumptions on my part?

(Yes, I do plan to take a closer look at my Movie Survey results in 
terms of this as well)

Oh, this weekend, I plan to add a feature to my site which will allow 
the user to send me their ranked ballots, with permission to use them 
further (if desired) and verifiable information on how they were 
generated. I might suggest that for those of you with voting 
calculators of your own to add a similar feature so that we can start 
building a database of real ballot data which can then be used to 
help judge various methods.