Just when we have started to get our heads around MMP, people are now kicking around the supplementary member electoral system (SM) as an alternative (Key and the anti-MMP campaigners seem to like it).
So what’s wrong with SM?
The amount of votes you get does not determine the number of seats you get i.e its not proportional.
If it isn’t proportional then it isn’t representative, and if it isn’t representative – it isn’t really democratic (well not a fair version of democracy anyway).
So how does SM work?
Under SM you have electorate seats that work under the old system, so the person who gets the most votes wins (and all the other electorate votes don’t count for anything). You then have a limited number of seats which are decided on a party vote.
So, for example, you could have 100 electorate seats determined under a first past the post model and 20 seats determined on the party vote.
Under this example if a party gets 10% of the vote but doesn’t win any electorate seats then they would get 2 seats (10% of the 20 seats determined on the list).
Seem fair to you?