[EM] Condorcet strategy and weighted pairwise method

[Dave Ketchum]

On Tue, 20 Jul 2004 17:41:44 -0400 James Green-Armytage wrote:

> This is James Green-Armytage replying to Dave Ketchum.
> 
>>
>>The method cannot avoid introducing pain.  While I have the option of 
>>refusing to do ratings:
>>     I cannot do that intelligently without understanding the option.


What I see is that these ratings are the change, claim more intelligent 
selection of winner among Condorcet cycle contenders, and have no effect 
unless cycles occur.

James seems to include permitting giving candidates equal rankings as part 
of this change.  I see that as part of Condorcet - at least addable 
without these ratings - and thus not countable as part of this enhancement.

He prefers winning votes over margins - which seems to get general 
preference for Condorcet.


>>     Since other voters could use the feature, I need to understand what 
>>they could do to me with it.
>>     If I get in deep enough, I start wondering how default ratings 
>>interact with truncation (I see that you do describe one variation - 
>>bullet voting).
>>
> 
> 	Sure, any method that is more complex than plurality, two-round runoff,
> or approval is a challenge to voters in terms of understanding exactly how
> their vote will be processed. Even IRV is relatively challenging for
> voters to understand, if they've never dealt with stuff like that before.
> Any Condorcet method is challenging, as well... to fully understand it,
> voters need to learn about pairwise comparisons, the Condorcet paradox,
> and the particular cycle-breaking technique. My method probably adds an
> extra layer of complexity on top of that, I admit, because the
> cycle-breaking technique is relatively complex.
> 	However, the happy part is that, in my opinion, you don't need to be
> strategically sophisticated to cast an effective vote in weighted
> pairwise. If people rank sincerely, and rate sincerely, the result will be
> a good one. I think that there aren't a lot of situations where a
> sophisticated vote will have vastly more "power" than a sincere vote, if
> you keep the definition of power in probabilistic terms, such that you
> assume that voters will not know what the direction of cycles will be if
> they arise. 
> 
> 	Anyway, I concede that this is a relatively complex method. Whether the
> complexity is worth it depends on your situation, I think. Will the voters
> be unwilling to learn the rules a complex method, and be hostile to a
> method that they can't understand? If so, weighted pairwise might not be
> the best bet. At this point I don't know how soon I can hope to see
> weighted pairwise. 
> 	I think that the first question for me is whether it is superior to
> rankings-only Condorcet in an electorate that is not hostile to complex
> methods. That question is important to me in itself, because I like to
> peer into the future and imagine what voting methods people will be using
> in a much more democratically-advanced society.
> 	As for what to promote if people are hostile to complex election methods,
> I don't know exactly... That's a whole 'nother question, one which sort of
> ties your hands as a voting methods designer.
> 
>>>And my answer to the question
>>>is, sure, it's a small price to pay.
>>>
>>Let's see:
>>     "small" requires comparing benefit vs cost, and I remain suspicious 
>>on both ends.
>>
> 
> 	Okay, well, specific arguments as to this are welcome. Again, I think
> that the only substantial cost is getting computerized systems with an
> interface that allows you to enter numbers. Once the software is produced,
> the cost of providing copies to the various precincts is virtually nil. 
> 	I've already talked about the benefits. First, it has all the benefits of
> a Condorcet method, since it is a Condorcet method. Second, it resolves
> cycles in a more meaningful way than rankings-only Condorcet, because it
> takes into account strength of preference. Third, it may prevent strategy
> from getting out of hand in Condorcet, which I'm still convinced is a
> significant issue.
> 

On equipment cost, I claim true electronic voting machines, able to do 
Condorcet and handle writein votes, should be basic.  Adding ratings to 
this seems trivial.

On human cost, candidates in a cycle are already in a near tie for 
winning, and the added ratings only affect selecting the winner among 
these - BUT - if the feature is available, voters must consider using it 
if they see a possibility of a cycle.

Benefits do not happen as often as some EM members might suspect from the 
time we spend on cycles:
      Requires at least three candidates in serious contention - MANY 
races have only one or two after you cross off sure losers.
      Must not only be near a tie, but there must be no single winner.

So, the cost is not huge, but neither are the benefits - the candidate who 
lost out due to ratings had to be near winning to be in a cycle.

> 
>>     Argue paper trail another day.
>>
> 
> 	There's actually an argument against paper trails for voting machines?

The mechanical voting machines I, and many others in NY and other states 
have used for decades:
     DO NOT do paper trails, 
     DO preserve voter secrecy,
     DO get tested to verify that they truly are voting machines that let 
voters express their intent and correctly count and report the results.

Attend to the two DOs and I would not care about the DO NOT - but  suspect 
many would then lose interest in having that expense.
> 
>>With IRV, voter's first choices can get summed by state but, when a loser
>>is 
>>recognized, voting patterns are needed to do the substitution.  These
>>patterns 
>>could have been sent up by the precincts (added load - NY has a few
>>million 
>>ballots for governor), or could be requested as needed by state
>>(computers 
>>with this data must stay available).
>>
> 
> 	With IRV, you can put the FULL results for a precinct on one or two
> DVD's. You can then physically carry the DVD's via courier to the central
> tally location, at which point all the DVD's will be fed into a big
> computer, which will look at the ballots in full and give you a result.
> 	If you don't want to wait for the courier to find out the winner, maybe
> you could transmit an unofficial version of the full result from each
> precinct via a secure internet connection, tally an unofficial winner at
> the central location, and then wait for the couriers to come and enter the
> DVD's to double-check the result and make it official.

Net is that rating data can be stored and reported with Condorcet rank data, 
thus not creating any extra need for couriers, etc.
> 
>>With your method...?

Looking closer I see summable, needing a second matrix of the same size for 
the ratings.  You only want half the ratings, but it is likely easier to 
calculate them all in a single precinct district, and almost essential to 
do this in a multiple precinct district, since the precinct does not have 
a district rank matrix.

>>Brian is almost certainly doing the equivalent of a precinct, where
>>almost 
>>anything would be doable - and the doing could be useful to his audience.
>>
>>I am leaning on the problems of multiple precincts, such as states.
>>
> 
> 	Right. I can't see any reason why, if you really wanted to, you couldn't
> just take the sum of precinct matrices to find state matrices, in my
> method. Again, I think probably the way to do it is to have a
> straightforward pairwise matrix, which is summable, plus a ratings
> differential matrix, which is also summable, as far as I can imagine...
> these two summable matrices together will tell you the winner.
> 
> my best,
> James
> 
> 
> P.S. the proposal for weighted pairwise is currently at 
> http://fc.antioch.edu/~jarmyta@antioch-college.edu/voting_methods/weighted_pairwise.htm

-- 
  davek at clarityconnect.com    people.clarityconnect.com/webpages3/davek
  Dave Ketchum   108 Halstead Ave, Owego, NY  13827-1708   607-687-5026
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