[EM] RE: Definition of Sincere Approval voting

Simmons, Forest simmonfo at up.edu
Mon Sep 19 14:44:32 PDT 2005

Perhaps we could distinguish "sincere approval strategy" from merely "consistent approval strategy" according to whether both or only the first of Chris' conditions are satisfied.
I agree strongly with Chris' remark concerning the advantage of DMC zero info strategy over Shulze(WV) zero info strategy.  
Chris' remarks corroborate what I have been saying about weak versus strong FBC.  There is never any advantage to ranking Favorite equal to Compromise under zero info DMC, but there is in Shulze(wv), e.g. when Favorite and Compromise are rated close to each other compared to the next candidate down.
I have noticed that often the zero info DMC winner is better than the zero info sincere Shulze winner, though weak betrayal of favorite (as suggested by Chris) can improve the Shulze(wv) winner.
Zero Info DMC:
40 A>>B>C
25 B>C>>A
35 C>>A>B
C is the DMC winner, but A would be the sincere Shulze winner.
Under Shulze(wv)  the B supporters (using the zero info, half sincere, strategy mentioned by Chris) must weakly betray their favorite B to achieve the same result:
25 B=C
The Shulze(wv) winner improves to C.


Chris Benham wrote:

This is my proposed clear definition:
"An  'approval vote' is one that makes some approval distinction among
the candidates. It is sincere if
(1)the voter sincerely prefers all the approved candidates (or single
candidate) to all the not approved candidates (or single candidate), and
(2) it is how the voter would vote without any knowledge or guess as to
how other voters might vote."

By this definition, DMC  (like IRV and unlike WV) meets  "No
Zero-Information Strategy".  No method can make it impossible for
strategists to sometimes have an advantage, but it irks me that WV  has
non-obvious fairly sophisticated strategy for "zero-information" voters
(random-fill and if you have a big ratings gap, equal-rank above it).

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