[EM] favorite betrayal and 2-party domination in Condorcet(wv, =); and about DMC

[Juho Laatu]

On Sep 6, 2005, at 04:47, Warren Smith wrote:

> So.  from the point of view of US third parties,
> 1. all Condorcet methods plausibly lead
> to 2-party domination, though we cannot be sure,
> 2. all are more complicated
> than range voting, and
> 3. range voting apparently does NOT lead to 2-party domination.
>
> Therefore, US third parties should push range voting in preference
> to all Condorcet methods.   (Doing the reverse would be 
> idiotic/suicidal, name
> your favorite adjective.)

You are probably using stronger expressions that many people on this 
list would be prepared to use. How about the following slightly 
modified formulation? It may be a bit soft for your taste but more 
approvable at least to me ;-).

--modified text--
So.  from the point of view of US third parties,
1. all Condorcet methods have some tendency to lead
to 2-party domination, though we cannot be sure if the shift would 
happen in real life,
2. all are more complicated
than range voting in some aspects (e.g. calculation of results), and
3. range voting has NOT been shown to lead to 2-party domination.

Therefore, US third parties could consider also range voting in addition
to the Condorcet methods.   (Doing the reverse could mean not 
understanding all the relative merits that different election methods 
may offer.)
--end modified text--

On point 3. I have also an extra comment. If sincere range voting 
preferences are A:100, B:80, C:0 and the voter strategically votes 
A:100, B:100, C:0, isn't that also one type of favourite betrayal that 
weakens the position of the (small party) candidate A? The Electowiki 
definition of FBC talks about "voting someone over his favourite", but 
in range voting already making the gap between A and B smaller has 
influence (unlike in ranking based methods) and could be considered a 
"betrayal". And giving less support to small parties could lead to 
2-party domination.

BR, Juho


P.S. Note also that one member districts and "winner takes all the 
seats" practice are also quite meaningful when it comes to creating or 
maintaining two-party systems. And note that many people promote 
Condorcet methods because of their tendency to reduce the 2-party 
domination of the currently used voting methods.