[EM] strategy-free Condorcet method after all!

[fsimmons at pcc.edu]

Dave,

Jobst, the inventor of River, is well aware of the cycle problem, and Jobst
would never advocate public use of a Condorcet method that failed clone loser,
for example, but as near as I know his simple reverse Llull method is the first
Condorcet method that gives zero incentive for insincere rankings, even if
complete rankings are required (at least generically).  As a corollary, it
satisfies the Strong FBC.  No other extant Condorcet method does even that.

In other words it is a benchmark method.

It gives us something to shoot for; a clone free version of the same, for
example.  The complicated method you referred to was my crude attempt at that.

Forest




Dave Ketchum Wrote ...

>Took me a while, but hope what I say is useful.

>Jobst had good words, except he oversimplified.

>Centuries ago Llull had an idea which Condorcet improved a bit - 
compare each pair of candidates, and go with whoever wins in each 
pair.  Works fine when there is a CW for, once the CW is found, it 
will win every following comparison.

>BUT, in our newer studying, we know that there is sometimes a cycle, 
and NO CW.  Perhaps useful to take the N*N array from an election and 
use its values as a test of Jobst's rules:
      There may be some comparisons before the CW wins one.  Then the 
found CW will win all following comparisons.
      BUT, if no CW, you soon find a cycle member and cycle members 
win all following comparisons, just as the CW did above.

>Summary:
      We are into Condorcet with ranking and no approval cutoffs.
      Testing the N*N array for CW is easy enough, once you decide 
what to do with ties.
      Deciding on rules for resolving cycles is a headache, but I 
question involving anything for this other than the N*N array - such 
as the complications Jobst and fsimmons offer.

>Dave Ketchum