[EM] Condorcet divisor method proportional representation

[Juho Laatu]

On 4.7.2011, at 16.33, Kathy Dopp wrote:

> I must say then, I simply do not like the Droop quota as a criteria
> because it elects less popular candidates favored by fewer voters
> overall and eliminates the Condorcet winners some times.

If you want the most popular single candidates to be elected (e.g. Condorcet winner), and you do not require 100% best proportionality, then maybe you like methods that are based on proportional ordering. Also your interest in organizing the party lists in some preference order points out in this direction.

Proportional order based methods thus do not provide the best possible proportionality but they are close. Typical proportional order methods follow philosophy where you fist pick the winner if there is only one representative. That would be the Condorcet winner. The next candidate is the one that makes a two seat representative body most proportional, but with the condition that the first candidate will not be changed. And so on for the rest of the seats.

Proportional ordering methods are also algorithmically simpler than methods that seek best possible proportionality. (Methods that seek ideal proportionality do not respect the condition/limitation of creating an ordering that increases the number of representatives one by one.)

If you want to put emphasis on always electing the most popular ones of the candidates, but keep good proportionality at the same time, and not allow majority to take all the seats, then maybe proportional ordering methods are close to what you want. They may also not always elect the next most popular candidate, if e.g. some wing has already had its fair share of candidates, but maybe they offer a good approximation of what you want.

Juho