Last month, the New Zealand Herald made some rather stupid statements about MMP and representation, suggesting that it had done nothing to improve the representation of women, Maori and immigrants. This is demonstrably false, but facts apparently no longer matter to our "newspaper of record". But at the end of the piece, they also suggested an "improvement" to MMP: doing away with the party list and instead awarding list seats to a party's highest-polling losers in electorate contests. It's a stupid idea, reflecting the FPP revanchist's obsession with geographic electorates, and ignoring completely the fact that parties (e.g. the Greens) or even MP's (e.g. Tim Barnett) can have national constituencies with votes distributed thinly (and pseudo-randomly) across electorates, but it also touches on one of the key concerns around MMP: accountability. Many people (usually old, dead ones like Granny Herald) feel that list MPs aren't really accountable to voters, but only to the party hierarchies which select them. This ignores the democratic list selection procedures used by some parties, but they feel that way nonetheless. Granny Herald's solution is to force every MP to stand in an electorate and pander to parochial concerns. I have a better one: we should vote for list MPs directly.
This is known as open-list proportional representation, and it is used in other PR jurisdictions, including most of Europe. And its perfectly compatible with MMP. How would it work? Mostly, like the present system - you would have two votes, an electorate vote and a party vote, with the latter determining the overall makeup of Parliament and the number of list MPs. The difference is that where currently we make our party choice on a ballot showing a list of parties, each party would instead have its own ballot, showing its party list. To vote for a party, you take its ballot, and tick a name on their list. The party list is reordered, wholly or partially, depending on how many votes each list candidate received.
I say "wholly or partially" because there is more than one way to do this. Some versions use full open list, where the party ordering is just a tiebreaker, and the actual order is determined by the number of votes each list candidate received; others place greater weight on a party's choices, and require list candidates to exceed some quota before disrupting the default order and being bumped to the top. But either way, you have a mechanism for imposing accountability across a national constituency and enabling voters to directly pass judgement on list MPs. And its a much better system than the parochial one proposed by the Herald.
Unfortunately, this would be difficult to implement - it requires changing the method of voting, and hence needs a 75% majority or a referendum to overcome the entrenchment clause. But its basically a minor change, and the politicians can do it for us if we let them know loudly enough that we want it.