[EM] MCA cut off points arbitrary?

Gervase Lam gervase at group.force9.co.uk
Thu Feb 27 17:14:35 PST 2003

> How should voters vote given that each voter would have their own
> utilities for each candidate?

> Thanks,
> Gervase.

One thing that I keep on forgetting is that in MCA, if no candidate has 
more than half of the Favored votes, then the candidate getting the least 
number of Unacceptable votes is the winner.  This is the same as the 
candidate who gets the most 'Favored' + 'Acceptable' votes, which is the 
way MCA is usually worded.

Therefore, how to find out where the MCA cut-off would be in terms of 
Utilities is easy.  The candidates with utilities below 50% would get the 
Unacceptable votes.

The Utilities are then re-calculated on the candidates that would not get 
the Unacceptable votes.  The candidates with utilities below 50% would get 
the Acceptable votes, while those above would get the Favored votes.

I quite like Alex's use of 'Unacceptable' as the lowest level as it seems 
to convey that the candidate would be given a 'Fail' mark, if each 
candidate were only allowed to be given either a Pass (more than 50%) or a 
Fail (less than 50%).  This fits in with how to vote in MCA in terms of 

The "opposite" of 'Unacceptable' is 'Acceptable'.  However, 'Acceptable' 
usually conveys the meaning "good enough", "satisfactory" or "OK".  So, 
this leaves room for 'Favored' which I think I prefer over 'Preferred'.

'Prefer' is ambiguous to me.  As the voters 'prefer' the 'Acceptable' 
candidates to the 'Unacceptable', adding in a 'Prefer' voting level 
confuses things.

Also, 'Favored' is connected to the word 'Favorite', as in your favorite 
candidates.  However, looking at a thesaurus, 'Favor' is synonymous with 


For more information about this list (subscribe, unsubscribe, FAQ, etc), 
please see http://www.eskimo.com/~robla/em

More information about the Election-Methods mailing list