[EM] MDDB order-reversal with defensive truncation

[MIKE OSSIPOFF]

With Condorcet(wv), and with MDDA and MDD,ER-Bucklin(whole), defensive 
truncations causes offensive order-reversal to fail and backfire.

That isn't true of MDDB. But MDDB doesn't do badly in that regard either.

With MDDB, with 3 candidates, A, B, & C, if B is the middle CW, and the A 
voters insincerely rank C over A, then:

For A to win requires that C be the smallest (in terms of 1st choice 
support), and that A be twice as big as C.

So the defensive truncation makes it significantly less likely for the 
offensive order-reversal to succeed.

For the A voters' offensive order-reversal to not backfire requires that 
A>2C or B>3C. Certainly neither of those things can be safely counted on, 
and so MDDB has some good order-reversal deterrence when defensive 
truncation is used.

Not as good as MDDA and MDD,ER-Bucklin(whole), but still pretty good.

Mike Ossipoff

_________________________________________________________________
FREE pop-up blocking with the new MSN Toolbar – get it now! 
http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/