[EM] Truncation

[Alex Small]

Adam Tarr said:
> I spent some time a few months back seeing if approval-completed
> Condorcet  could be made to work using this sort of ballot, but in the
> end I realized  that the only time approval completion worked like I
> thought it should was  when the approval votes supported the sincere
> Condorcet winner.  When the  approval votes did not do so, the system
> encouraged all sorts of strategic  manipulations.  So I gave up on ACC,
> and I now hang my hat with
> winning-votes based Condorcet, which seems to be the system that is
> most  resistant to strategic manipulation by a wide margin.


I went through a similar thought process.  ACC seems so great, because it
offers a fairly transparent criterion for resolving cyclic ambiguities. 
By contrast, dropping defeats based on either margins or wv requires more
explanation and justification.

However, you have 2 separate scores being kept, which not only leaves room
for manipulation, it also raises legitimacy questions.  When the process
is determined entirely by the relative rankings there is no danger of "a
Pope and anti-Pope." (Thomas Jefferson's critique of they way electoral
college deadlocks are resolved.)  Then again, in 2000 we kept a tally of
both popular votes and electoral votes, and (sadly) not too many people
got bent out of shape when they didn't match up.

Anyway, count me in the wv camp now.



Alex


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