[EM] Anyone got a good analysis on limitations of approval and range voting?

[Kristofer Munsterhjelm]

robert bristow-johnson wrote:

> my understanding is that the later-no-harm result happens only if the 
> case of a Condorcet cycle (the prevalence of which i am dubious about).  
> where there is a Condorcet winner and that person is elected, is there 
> still possible later harm?

As far as I remember, Condorcet and LNHarm has the property that LNHarm 
isn't, by itself, violated as long as there is a CW, but the transition 
from CW to no CW (or vice versa) makes it inevitable that there will be 
a LNHarm-violating discontinuity *somewhere*.

In other words, as long as you stay within the CW domain, there is no 
LNHarm failure, but there is no way to engineer a completion rule to 
maintain this for every CW<->no CW transition.

I'm not entirely sure about that, though - can anyone confirm?


Not that this bothers me - LNHarm seems to me to be a criterion of 
"don't take the full picture into account". Consider a negotiation 
situation: if everybody keeps their cards close to their chests (i.e. 
vote bullet style), there can be no compromise; but if they're willing 
to reach further, one might find an option that, while not the favorite 
of any, is good enough for all. An LNHarm-respecting method has to act 
as if people are voting cautiously before it can consider any additional 
information, and thus it misses such opportunities for compromise.