--- On Wed, 25/3/09, Jonathan Lundell <jlund...@pobox.com> wrote: > Lam wrote: > > > IRV can be made sort of summable: > > > > <http://lists.electorama.com/htdig.cgi/election-methods-electorama.com/2001-September/006595.html> > > > > Buddha Buck replied with an IRV example that much more > clearly explained > > the method: > > > > <http://lists..electorama.com/htdig.cgi/election-methods-electorama.com/2001-September/006598.html> > > > > Quite neat I think. > > Yes, but...what's the point? That is, what problem are you > trying to solve, exactly? > > If you're in a position to compute the matrix, why not > simply send the file of ballot data? It's not as if it's > going to be prohibitively large. The 2008 US Presidential > election had ~13 million votes in California, the largest > state. Ten candidates at a byte per candidate would only be > order of a 100MB for the entire state, before compression. > Heck, I've got mp3's bigger than that.
Yes, good question. IRV votes thus don't take excessive amount of space and can be compressed and can be summed up (although not very compactly). Possible answers might include: 1) To help verifying the vote counting process. If the partial results are counted/verified already locally it may be more difficult to falsify the results. With the modern personal computers it is however also possible to anyone to collect all the <100MB files in one's own computer and verify the election if all the districts publish their ballots. 2) To build trust on the system by showing the partial results to people. In this case the summed partial results should be very simple so that every regular voter can see that they are ok. A Condorcet pairwise comparison matrix might be too difficult. Sum of votes per each candidate could be simple enough. Also publishing the outcome of the election based on the votes of one district alone can help (although these results would not be further used / usable when summing up the results). This is easy enough for all methods. And the voters will see if the results are credible, not e.g. opposite to what everyone expected. 3) For general interest. The local results in point 2 above are certainly interesting. One must be capable of summing up the results so that one can see what happened. Also this case does not set a requirement of reusing these "summed up" results later in the process when the election wide results are counted (raw ballot data will do). (Also the Condorcet pairwise matrix may be very interesting material to study and speculate on.) 4) To hide the individual votes for privacy and security reasons. Published ranked votes open up some doors for vote buying and coercion. It is quite easy to generate unique votes when the number of candidates increases. (Also individual ballots are interesting from point 1, 2 and 3 point of view, but dangerous.) 5) To distribute the load of vote counting and to speed up the process. This mostly applies to hand counting. In the time of computers it may be enough to just digitize the votes locally (unless already digital) and to verify these transformations. 6) To keep possible recounts local. This is also mainly related to hand counting. Nowadays local re-digitization may often be enough.. In summary, maybe raw digitized ballots are good enough in most cases for the computers, but humans may need more compact information (not necessarily summable) for various reasons. The privacy point may set requirements on what to publish and what not (some countries are already now quite strict on this). In IRV there may thus be a need to keep the ballots hidden or to break them in such a way that individual ballots can not be recognized (or verified to the buyer/coercer). Juho ---- Election-Methods mailing list - see http://electorama.com/em for list info