[EM] UncAAO

Forest W Simmons fsimmons at pcc.edu
Sat Mar 3 17:38:56 PST 2007


Mike,

That's right.  The C voters still have to use defensive strategy, but 
the moving the approval cutoff is sufficient.

When there are only three candidates, UncAAO is the same as Smith 
Approval.

Here's another classical example:

49 C
24 B>A
27 A>B

Under wv, this is not a Nash Equilibrium, because B can unilaterally 
gain by truncating.

But if the direct supporters of the CW strategically put their approval 
cutoff just below A, then we end up with a Nash equilibrium, no matter 
where the B faction puts its approval cutoff.

49 C
24 B>A
27 A>>B

As in wv, no defensive strategy is needed under zero info conditions.  
But if you suspect that X is the CW, and you could live with X, then a 
prudent move would be to approve X and above.

Forest



Michael Ossipoff wrote:


>
>Forest--
>
>Alright, but the C voters are still truncating their approval, aren’t 
they? 
>They still need that strategy in order to put the choice to the A 
voters 
>about accepting the Nash equilibrium or else. True, the C voters don’t 
have 
>to abandon A to the degree that they’d have to in wv. So they don’t 
need as 
>drastic a strategy against offensive order-reversal as they’d need in 
wv. 
>(Truncation didn’t seem drastic until it’s compared to the only-partial 
>truncation of UncAAO).
>
>Now, if UncAAO meets (what I consider) the deluxe rank-method criteria, 
SFC 
>and SDSC, that means that, while reducing the amount of defensive 
strategy 
>needed against offensive order-reversal,  UncAAO retains the full 
advantages 
>that a rank method can have over Approval.
>
>Maybe this is one of those times when something is found that is a 
little 
>better than what was believed possible.
>
>If the strategy in your example always works, then that probably means 
that 
>UncAAO meets SDSC. But what about SFC?
>
>Well, GSFC would be even better than SFC, but SFC would be good enough.
>
>I have other questions about UncAAO, but I’ll save them for another 
posting.
>
>Mike Ossipoff
>
>
>


More information about the Election-Methods mailing list