[EM] Examples: Margins, strategy pushover

[Blake Cretney]

On Sun, 29 Apr 2001 02:30:55 -0000
"MIKE OSSIPOFF" <nkklrp at hotmail.com> wrote:

> Proponents of other voting systems always say that pairwise-count
> methods are strategy-ridden. I'm going to show some examples here,
to
> show that they're right--when the method a Margins method.

My problem with your analysis is that you decide that truncation is
the chief enemy, so you construct a method that on average punishes
people for using partial rankings (strategic or not).  But if they
want their ballot to be fully counted, they can still randomly rank
the rest of their ballot.

These wv arguments really help IRV in the long run.  You play up the
strategy problems of Condorcet methods, offering wv as the only
solution.  Maybe people will be so convinced of the strategy problems
that they are willing to accept anything offered as a solution, out of
desperation.

Then, I come along and point out that wv doesn't really do any good
after all.  The result is that people might be left with the
impression that Condorcet is hopeless.  Even if I didn't point out
wv's problems, IRV advocates would, if wv became more well known.

For example, you claim that there are "easy situations" where
truncation is safe to use in margins.  Clearly, in wv, the usurpers
could randomly rank the remaining candidates instead of truncating. 
So, really, we can only conclude that strategy is easy in wv too.  Of
course, that isn't considering the truncation-for-sheer-spite
strategy.

It's ironic that truncation is made such an issue.  It isn't really
ever good strategy to truncate, or randomly rank, in either margins or
wv.  If you're tempted to use partial rankings as a strategy, order
reversal is even better.

---
Blake Cretney