Yes, Pareto front is a good way to describe the possibility of
different methods being best for different needs. It is of course
difficult to agree what the parameters in this calculation should be
measured. It may be also difficult even for one person to set the
parameters. But also use of this type of argumentation in regular
discussion makes sense. Let's hope people will be more analytical in
this sense in the future.
Juho
On Jan 23, 2010, at 1:36 PM, Kristofer Munsterhjelm wrote:
Juho wrote:
Many of the criteria would be nice to have. One must however
remember that often they have two sides. Winning something in some
area may mean losing something in another area (e.g. the LNH
property of IRV has been discussed widely on this list recently)
especially when trying to fix the last remaining problems of the
Condorcet methods. And if one assumes that strategic voting will
not be meaningful in the planned elections then one should pay
attention also to performance with sincere votes, not only to the
resistance against strategies. Different elections may also have
different requirements, so the question of which one of the methods
is best may depend also on what kind of winner one wants to get
(e.g. in some cases the best winner could be found outside the
Smith set).
That's true. Some of the criteria are mutually exclusive, yet others
are not. By picking criteria of "worth", one might build a Pareto
front: those methods on the front are those that fulfill as many
criteria as possible subject to that some are mutually exclusive.
If we didn't forget notable criteria (and thus exclude from the
Pareto front methods that by all means should be there), then the
front provides the best methods we can get. It's up to one's
judgement which of the criteria count more, i.e. which method on the
Pareto front one should pick.
For convenience's sake, I've ignored the problem that criterion
compliance might degrade the method's "goodness" when given honest
votes, and that we don't know which criteria are mutually exclusive.
For the former, we (E-M members) disagree about how to go about
measuring how good results a method provides on honest votes, and
for the latter, we can still build a Pareto front based on the
methods we know so far - but it might be incomplete.
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