[EM] Chris, DD

[Chris Benham]

Mike,

You wrote:

> I can't agree or disagree without knowing what DD
is. DD stands for direct democracy, but I assume that
that isn't what you're referring to. 

Well, if you even looked at the subject line of my
last two EM posts ("Burying and defection with the
defeat-droppers"), or remembered that you began your
own Fri.Mar.18 "Chris, equal-ranking incentive" post
with a quote from me referring to "...Winning Votes
defeat dropper"; then you could have had a good guess.
But yes, I forgot about "direct democracy" so maybe I
should consider the "DD" abbreviation taken.

In a previous message you wrote:

> "Still, it would be a nice luxury for everyone to
have no incentive to do other than sincerely rank
those better-set candidates." 


I responded:  I am sure that SCRIRVE, and doubtless
some other methods, fill that bill.

You replied:
 

> Doubtless some do. Margins does. Maybe SCRIRVE does
too. The problem is the bills that they _don't_ fill.
When they avoid that mild strategy incentive, while
causing serious strategy dilemmas in which majorities
are strategically forced to reverse their preferences
or bury their favorite in order to protect the win of
a CW or to protect majority rule, then I suggest that
those methods are losing more than they're gaining for
the voter who wants to reduce strategy need. 

Unlike Margins, SCRIRVE  has the property that if more
than half the voters rank y above x, and x no higher
than equal-last; then x can't win (thus meeting
Minimal Defense).
Also I have it meeting Steve Eppley's "Truncation
Resistance" and  (in the version that allows non-last
equal ranking) also his "Non-Drastic Defense", i.e. it
has the property that if more than half  the voters
rank y above x and y now lower than equal-first, then
x can't win.
Unlike Defeat-Dropper(Winning Votes), there are no
equal-rank  or random-fill incentives, because meeting
Symmetric Completion the method in a sense doesn't
even "know" if the voter has done that.
Unlike Margins, SCRIRVE meet the Plurality criterion.
Like all versions of  Defeat-Dropper, it meets 3-small
Mono-raise.  But when there are more than three
candidates in the top cycle, then it probably fails
Mono-raise.

In a future post I'll have a bit more to say on 
"Definite Majority Choice", perhaps comparing it with
Approval Margins and Approval-Weighted Pairwise.

Chris Benham



Find local movie times and trailers on Yahoo! Movies.
http://au.movies.yahoo.com