[EM] MDDA vs UncAAO, ASM & DMC

[Michael Ossipoff]

MDDA and MAMPO (if modified to allow voting an Approval line instead of 
saying that all ranked candidates are approved)  share UncAAO’s advantage of 
a majority being able to make a candidate lose while still ranking him. But, 
since it’s necessary to know to not approve him, it’s not as if no strategy 
is needed.

UncAAO, ASM, and DMC ignore defeat-magnitude and magnitude of pair-wise 
opposition. They look at pair-wise vote totals in order to find out who 
beats whom, but then they throw pair-wise vote total information away. 
Throwing that information away has regrettable consequences.

As exemplified by my majority defensive strategy criteria, it’s possible to 
make some guarantees to a majority that couldn’t be made to a smaller group. 
So it’s desirable for a method to be able to recognize a majority.

An Approval count can recognize a majority. If a majority approve X but not 
Y,  then there’s no way that Y can win. That’s why MDDA and MAMPO meet SDSC. 
And maybe so do some or all of the other methods listed above.

But what if you’re interested in not having to use any strategy at all under 
certain conditions. Then Approval strategy is out. Then it’s about rankings 
and pair-wise preferences. To recognize a majority pair-wise preference, 
it’s necessary to look at pair-wise vote totals, other than just to find out 
who beats whom.

That’s why UncAAo, ASM and DMC don’t meet SFC, and don’t offer the  freedom 
from strategy need that SFC confers under plausible conditions.

Mike Ossipoff