[EM] Summability

[Kevin Venzke]

 --- Markus Schulze <markus.schulze at alumni.tu-berlin.de> a écrit : 
> ... that when V is the number of voters and C is the number of candidates
>     then the runtime to calculate the pairwise matrix is O(V*C*C) while
>     the runtime to calculate the IRV winner is only O(V*log(C)) so that
>     while the Condorcet supporters are still summing their matrices the
>     IRV winner is already preparing his inaugural speech.

But wait a minute...  With the IRV count, you have to know what happens earlier
(e.g., the first elimination) to know what to count later.  With Condorcet,
you're always counting everything, so the task could be divided up among a number
of computers, couldn't it?


> The main question is whether summability is a desirable or an undesirable
> property. I am aware that there are scientists who consider this property
> undesirable (e.g. Nurmi, Bartholdi, Bowler) since compliance with this
> property means that it is easier to get the information you need to run
> a strategy. But I don't know any scientist who considers this property
> desirable.

I'm surprised to read this.  I thought "simple strategy" was a virtue for an
electoral method.  Surely runtime isn't considered a serious issue for summable
methods...?

Kevin Venzke
stepjak at yahoo.fr


___________________________________________________________
Do You Yahoo!? -- Une adresse @yahoo.fr gratuite et en français !
Yahoo! Mail : http://fr.mail.yahoo.com