[EM] Participation Criterion

[Richard Moore]

--- In election-methods-list at yahoogroups.com, Forest Simmons 
<fsimmons at p...> wrote:
 > For each ballot B, apply your method twice ... once to the set of all
 > ballots except B, and once to the set of ballots with B included and
 > replicated n times.
 >
 > Let the letters C1 and C2 represent the respective winners for the two
 > distinct ballot sets.
 >
 > If C2 is ranked or rated lower than C1 on ballot B, then label the 
ballot
 > with the letter "HO" for "hopelessly optimistic."
 >
 > After this procedure has been applied to each of the ballots, 
remove all
 > of the ballots with the HO label, as a favor to their voters, and 
perhaps
 > tabulate them separately for educational purposes.
 >
 > Apply your method to the remaining ballots to determine the winner.

Am I missing something? Wouldn't the "HO" label be applied to every 
ballot that is identical to ballot B, and not just to ballot B?

It might be that 30% is the optimal percentage for all B-like voters.
If 31% of the ballots are like B, then the 1% excess will cause the 
entire 31% to be marked for removal. Removing 31% of the ballots can't 
be good for those who cast them.

What you want is a procedure to determine the optimal level (subject 
to the constraint that the result is less than the actual level) for 
each type of ballot that appears.

Yet I still foresee a problem, in that several different groups of 
ballots may all be scaled back together, with perhaps less than 
desirable results for any of those being scaled back.

Couple that with the computational problem when the number of ballots 
runs in the thousands or millions, and it seems better to use a 
participation-compliant method in the first place, or else ignore the 
criterion.

  -- Richard