[EM] Oops! Forgot to include Chris's text. Chris MMT reply, complete this time.

[MIKE OSSIPOFF]

When I first posted this, a few minutes ago, I forgot to include the text that I was replying to.



In this posting, that text is present, and my replies are interspersed where they go.



Chris said:


> As far as I can see the examples I gave apply equally well to "MMT2".
> I've pasted them in at the bottom.


He was referring to his posting copied and replied to below:




>
> I think this (MMT2) fails the FBC. Say sincere is:
>
> 45: C
> 06: D>A
> 39: A>B
> 20: B>A
>
> There is no "mutual majority set" (by your latest definition)



My latest MMT version is still MMT2. It’s my latest, final,
and best MMT version.



 



By its definition of a mutual-majority candidate set, in
your example, {A,B} is a mutual-majority candidate set.



 



But if it weren’t big enough, and if the D voters wanted to
add themselves to it, then they’d have only to vote



D=A>B.  By MMT2’s
definition of a mutual majority candidate set.



 



Therefore, there would be no violation of FBC in your
example.



 



Your example illustrates a general fact: It’s possible to be
counted in support of any mutual majority candidate set without voting anyone
over your favorite. MMT2 meets FBC.



 



Chris continued:


> It also fails Mono-add-Plump.


 



I agree that MMT (by which I mean MMT2) fails
Mono-Add-Plump. As I explained yesterday, it wouldn’t make any sense for it to
meet that criterion. Mono-Add-Plump isn’t a useful or meaningful criterion.
I’ve told why that is.





> I think all reasonable methods will elect A in both cases.



 



That statement is perfectly acceptable as an expression of
your own personal impression. But if it were to be an _assertion_, then of
course you’d need to support it. Unless you wanted to define “reasonable” in
terms of one particular example.



 



I’m going to guess that, by “reasonable”, you mean
“Condorcet-complying”.  Or maybe
“Woodall-acceptable”.





> Electing C in

> the second case will have voters wondering why they bothered switching

> from FPP



 



I’ll be glad to explain that to them:



 



First, let me tell you two things that are _not_ why we
switched from FPP:



 



One: Because it’s important that we never get the same
result that Plurality would give.



 



Two: Because Plurality’s standard, “favorite of the most”,
isn’t a good standard.



 



“Favorite of the most” is a good standard. Some good methods
don’t use it. Some good methods use it.



 



By itself, it doesn’t furnish any majority-rule protection.
With any method, a majority can get its way. If the method doesn’t enforce
majority rule, then the voters will have to, which often creates an undesirable
need for drastic strategy. For example, in FPP, many or most voters were afraid
to vote for their favorite, always voting instead for some not-really-liked
“compromise”, thereby burying their favorite.



 



That’s why we switched from FPP. We’ve replaced FPP with a
method in which you’ll never have any need to vote someone else over your
favorite. It’s also a method that provides good majority-rule enforcement. 



 



[end of explanation for why we switched from FPP]



 



> , and is a very bad case of failing Condorcet



Condorcet's Criterion is incompatible with FBC.





> and Mutual Dominant Third (DMT).



For that to mean anything, you'd have to justify that criterion.



Mike Ossipoff 		 	   		  
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