[EM] majorities and ordinal-only pairwise methods

[James Green-Armytage]

James replying to Jobst...

Jobst, you wrote:
>I don't think at all that we should base a method
>ordinal information since I don't believe there can be sincere cardinal
>information. You probably refer to approval information as cardinal
>information, but that is only your interpretation of approval, not mine.
>I wonder what should be cardinal about a yes-no question...
>Anyway, here's why I think a (sincere) method should make use of all
>forms of preference information a voter *can* give in a sincere way
>(pairwise preferences, favourite, approval)

	I agree with those who consider "approval" (score of 1 or 0) to be a kind
of cardinal information. I'd like to know what makes you think that
approval information can be sincere (i.e. what is the definition of
sincere approval?), but that cardinal information cannot be sincere.

you wrote:
>As I understand James, his main point is strategic considerations, 

	I'll repeat what I wrote in my last message, in the same thread: 
	My main purpose in using cardinal information is to incorporate
preference strength into defeat strength, and thus to protect defeats that
consist of many strong preferences. 
	Using other information in addition to ordinal information also has the
potential to allow voters to engage in effective counterstrategy without
altering their rankings, which generally leads to greater stability in
strategy/counterstrategy scenarios. (This second reason is shared by
methods like AERLO/ATLO, S/WPO, etc.)

you wrote:
>and I
>welcome any evidence that a particular approval-aware method has good
>anti-strategical properties.

	Oh, wonderful! Are you fully aware of my "approval-weighted pairwise"
method (AWP)? AWP is basically the same thing as CWP, except for the fact
that only two cardinal scores can be given: 1 and 0. I suggest that it has
anti-strategic properties that are comparable to CWP, and that it is
significantly more strategy-resistant than DMC/RAV, AM, margins, and WV.
	Here are three recent posts where I argue that AWP has strong strategy
resistance:

April 3 (to Chris)
http://lists.electorama.com/pipermail/election-methods-electorama.com/2005-April/015454.html
April 2 (to Ted)
http://lists.electorama.com/pipermail/election-methods-electorama.com/2005-April/015442.html
March 26 (to Juho)
http://lists.electorama.com/pipermail/election-methods-electorama.com/2005-March/015341.html

my best,
James