[EM] 1 example in which Plurality fails all the defensive strategy criteria

[MIKE OSSIPOFF]

This example consists of voter preferences.

40: ABC  means that 40% of the voters prefer A to B and to C, and prefer B 
to C.

40: ABC
31: B
29: CBA

With those preferences,, Plurality fails WDSC, SDSC, SFC, GSFC, FBC, PBC, & 
PSBC, among others.

On another day I'll demonstrate that, but you can apply the various criteria 
to this example.

Actually it isn't difficult to find an example like that. Pretty much all 
that's needed is a CW who isn't favorite of the most.

Lately you've been hearing about criteria that sound roughly similar to 
mine. I'm not criticizing them because Plurality passes them. There's 
nothing wrong with showing in what ways  your favorite methods are the same 
as Plurality., the method that's already in use.

But I prefer to describe criteria that show how our favorite methods are 
_different_ from Plurality. Criteria that show why we prefer our proposed 
methods to Pluralitly, how those better methods can do better than the 
method currently in use.

Go figure. That's just what I wanted to do.   ...apparently bothering some 
especially loyal followers of tradition. Did your teacher tell you that 
criteria shouldn't say "prefer"? Or that the strategy problem is methods' 
vulnerability to strategy? It never ceases to amaze me what herd animals 
some peoiple are. If someone with some kind of official authority says 
something, then some people here will go to the most ridiculous extremes to 
stand by it, uphold it, defend it and fight for it.

Maybe there's time to tell why Plurality fails those criteria.

WDSC:

>From those preference rankigs, a majority prefer B to A.  If everyone votes 
for their favorite, A will win. How can the B>A majority keep A from 
winning? Only by the C voters voting for B instead of for C.

Does that sound familiar? It should.

Face it, Kevin: WDSC is nothing other than a literal and transparent 
description of the situation, the goal, the dilemma that progressives face 
in every election. The familiar lesser-of-2-evils pragmatic favorite-burial 
situation.

I said that about WDSC. I wasn't referring to Kevin's "Minimal Defense", 
which may well not be Steve's Minimal Defense.

Anything that fails WDSC automatically fails SDSC, a more demanding 
extension of WDSC.

SFC:

Again, a majority prefer the CW, B, to A. If no one falsifies a preference, 
then, in Plurality, that means that everyone votes for their favorite. The 
A>B majority, in addition to having to vote for their favorite because the 
criterion's premise says that no one falsifies a preference, also needs to 
do so because of the stipulation that they vote sincerely.

As I said before, the only way, in Plurality, to not falsify a preference is 
to vote for your favorite. If you vote for someone else instead, you're 
falsifying a preference for him/her over your favorite.

With that voting, A wins, in violation of SFC's requirement.

PBC & PBSC:

A majority prefer B to A. There can be no majority path of MPPs from A to B, 
because there can be no path of public preferences from A to B. That's 
because B is the CW, and no one is publicly preferred to the CW.

So the premise  conditions of PBC & PBSC are met. Again, if no one falsifies 
a preference, that means that everyone votes for their favorite, and that 
means that A wins, in violation of those criteria's requirement.

FBC:

The C voters can get their best possible result only by voting for B. That 
means voting B over their favorite.

I've posted some improvements in FBC, but I haven't yet posted a copy of FBC 
that incorporates all of those improvements. That will be along in 
subsequent days.

Mike Ossipoff

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