[EM] breakdown of Oakland mayor ballots

[robert bristow-johnson]

On Nov 13, 2010, at 1:20 PM, Bob Richard wrote:

> On 11/13/2010 8:09 AM, Kristofer Munsterhjelm wrote:
>>
>> Sand W wrote:
>>> Here are the results on an actual election: http://www.demochoice.org/dcresults.php?poll=OakMayor&type=table 
>>>  <http://www.demochoice.org/dcresults.php?poll=OakMayor&type=table>
>>>
>>> Perata (or maybe someone in his camp) accuses the other candidates  
>>> of "gaming the system" by promoting each other as 2nd choices.
>>>
>>> Some challengers tried to do that to IRV-leader Kriss Worthington  
>>> too, but he won by a landslide.
>>
>> Unfortunately, there isn't enough data here to check who would won  
>> under other methods, except for Plurality (where Don Perata would  
>> have won). To find out the social order for a Condorcet method, one  
>> would need the Condorcet matrix, and for most other methods, the  
>> raw ballot data itself.
>
> Raw ballot data is here:
>
>     http://www.acgov.org/rov/rcv/results/OaklandMayor/ballot_image.txt
>     http://www.acgov.org/rov/rcv/results/OaklandMayor/ 
> master_lookup.txt
>     http://www.acgov.org/rov/rcv/results/ballot_image_help.pdf
>
> Here is the Condorcet matrix from these data files (entries are the  
> number preferring the row candidate over the column candidate). If  
> your email program doesn't handle HTML tables very well, this might  
> be scrambled.


what a minute Bob, just comparing the Perata/Quan race, it appears  
that your totals are off by about 10000, when you compare to that  
DemoChoice results at http://www.demochoice.org/dcresults.php?poll=OakMayor&type=table 
  .  the IRV final round should be precisely the pair of numbers you  
get in the Condorcet matrix (why the hell did that format get used?,  
it should be a triangle so that the relevant numbers sit side-by-side).

you have

      Quan      53778
      Perata    51720

whereas the IRV round-by-round results are

      Quan      43825
      Perata    41949


so what gives?  that's a pretty big discrepancy.



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r b-j                  rbj at audioimagination.com

"Imagination is more important than knowledge."