[EM] My Favorite Deterministic Condorcet Efficient Method: TACC

[Kristofer Munsterhjelm]

Jameson Quinn wrote:
> 
> 
> 2010/11/8 <fsimmons at pcc.edu <mailto:fsimmons at pcc.edu>>
> 
>     A few years ago Jobst invented Total Approval Chain Climbing or TACC
>     for short.
> 
>     At the time I was too young (not yet sixty) to really appreciate how
>     good it was.  It is a monotonic. clone
>     free, Condorcet Efficinet method which always elects from the "Banks
>     Set," a nice subset of the Smith
>     Set (if not the entire Smith Set).
> 
>     It is easy to describe:
> 
>     (1) Initialize the variable S as the empty set  S = { }.
> 
>     (2)  While some alternative beats every member of S pairwise,
>     augment the list S with the lowest
>     approval alternative that does so.
> 
>     (3) Elect the last alternative added to S, i.e. the member of S with
>     the greatest approval.
> 
>     That's it.
> 
>     Obviously the method will elect the CW when there is one.
(...)

>     49  A>B (sincere is A>C)
>     27  B>C
>     24  C>A
> 
>     The sincere CW is C.
> 
>     Now suppose that the A faction buries C as indicated above:
> 
>     TACC will elect B. whether or not the A faction approves B.
> 
> 
> But if the A faction votes A>B>C (ie, if they approve C), then C wins. 
> So I think that this method would work best with only 3 rating levels 
> (only 2 approval levels) available.

Would this method be any good if "Approval" was changed into some other 
method that's burial resistant and monotone, like Plurality or Bucklin?

For Plurality, the "score" would simply be the number of first place 
votes, breaking ties by the number of second place votes, breaking ties 
by the number of third place votes, etc.

For Bucklin, the score for a candidate would be the number of candidates 
minus the round at which it attains a majority, breaking ties by how far 
above the majority it got. QLTD might produce even fewer ties.