The first point I would make is, not all PR systems have better gender equity representation in their the parliaments than we do. It's not a guarantee. One of the things that's true, though, is that if you have a PR system, what you don't normally have are single-member ridings. You often have multi-member ridings, which means that there isn't this business of once one candidate is chosen you no longer...you can't split half a gender, half a gender. If you have four members in a riding you can zipper it: two men, two women. That's easier to do and there's less resistance to that.
Rosie Campbell and Sarah Childs pointed out that you can still do it. It's a little bit tougher because we have the single-member ridings. I think there's this resistance to imposing rules on local associations. I think we have to worry about that.