MMP is currently being reviewed, with an issues paper due out in February. In anticipation of that, I'm doing a series of posts on the review questions. This one will focus on the fifth question:
What should happen when a party wins more electorate seats than it would be entitled to under its share of the party voteOr, what should we do about overhangs?
Overhangs are a Bad Thing. They distort the proportionality of the House, which is the reason we shifted to MMP in the first place. But they're also a necessary consequence of the system, the price we pay for having electorates. Given that we're committed to a mixed member proportional system, and list-only PR is not on the table in this review (it would require a referendum, both legally and morally), the question is how to deal with them.
Currently, the law has two ways of doing this. If the party is registered, we expand the size of the House. If its not, or an independent wins a seat, we don't. This is obviously inconsistent, and there seems to be no reason for the distinction (though, as an independent or an unregistered party has never won a seat, it doesn't particularly matter). One popular suggestion is that we should fix the size of the House and follow the second method for all extra MPs. I disagree, because this seems to distort proportionality even more. Its bad enough if a party wins more electorates than its entitled to. Its adding insult to injury if you then expect the other parties (and, indirectly, their voters) to pay for it.
