I would care less about the adverse economic consequences of our mixed member proportional (MMP) voting system, which were outlined in my last article, if they reflected the genuine democratic preferences of New Zealanders.

They are unlikely to do so, however, because of the constitutional and political weaknesses of MMP.  

The main argument advanced in favour of MMP is that it provides for wider representation of a diverse community than first past the post (FPP).  This is the outcome the Royal Commission intended.  It is, however, a poor argument.

While the gender and ethnic diversity of members of parliament has increased since MMP was introduced, greater diversity would have occurred anyway.  The increasing participation of women in many occupations illustrates the broader trend.

Another claimed advantage of MMP is that it would permit political parties to bring highly qualified people into parliament who might be put off by the need to contest an electoral seat under FPP.  A handful of members of parliament elected in the last five elections could arguably come within this category, for instance, Christopher Finlayson, Stephen Franks and Tim Groser.

The opposite outcome, however, is the norm.  People who have no special talents and who are overwhelmingly rejected in contests for electoral seats are elected to parliament as list members.  Alamein Kopu is an example.

This arises partly because MMP concentrates power in the hands of central party hierarchies that draw up the party lists.  Electors have no direct influence on the selection of half of all members of parliament.  List members of parliament often have too little to do.

Simplicity is an important criterion for electoral systems.  MMP scores poorly on this count.
The Electoral Commission reports that only 46 percent of voters surveyed at the last election found MMP either easy or very easy to understand.  The equivalent finding for non-voters was just 35 percent.

The Commission's surveys since 1995 show that between 31 percent and 79 percent of voters correctly identify which of the two votes is more important in deciding the number of members of parliament each party will have in parliament.  The experience of Germany is that a significant fraction of voters do not understand this fundamental feature despite 60 years’ experience with MMP.

Confusion over MMP is not limited to voters.  Just nine days before the 2011 by-election for the Te Tai Tokerau seat, Mana's Hone Harawira was asked on Radio Live, "What point would people achieve by voting for him [Labour's Kelvin Davis] and putting a Labour candidate back in?" 

Mr Harawira replied, "Well actually … that's the real point.  If nobody voted for Kelvin he would still get in anyway because he's on the list ...  and he's quite high on the list so he's going to get in." 

The interviewer did not challenge or correct Mr Harawira's mistaken view of how MMP works in a by-election.

Voters who do understand MMP, or trust someone who does, may be encouraged to vote strategically rather than for the party or candidate they would most like to represent them.

MMP institutionalises promise-breaking in post-election negotiations.  In 2008 National promised to remove the Maori seats.  This commitment was abandoned immediately after the election when National entered into a confidence and supply agreement with the Maori Party.
 
Fragile minority governments are much more common under MMP and small parties wield disproportionate influence.  This compromises the quality of decision making.

Australian journalist Janet Albrechtsen recognised these problems with MMP when she observed, "Forget democratic principles of voters knowing what they voted for and politicians being accountable for their promises.  Post-election horse-trading between minor parties and minority governments will mean election promises count for nought."

The political philosopher Karl Popper concluded that the ability of the electorate to throw out a government it dislikes is the key issue in evaluating voting systems.  This almost always happens under FPP or similar systems, but it does not often occur under MMP or other proportional voting systems.

In the lead up to the 1996 election, most people (including many New Zealand First voters) expected New Zealand First to enter into a coalition with Labour.  After the election it gave National three more years in power.

Electors will need to weigh up the advantages and disadvantages of MMP and the four alternative voting systems in making their choices on 26 November.
 
MMP and single transferable vote (STV) are proportional systems.  They suffer from the major disadvantages noted in this and my earlier article.  FPP and preferential voting (PV) are non-proportional majoritarian electoral systems.  Supplementary member (SM) is also a non-proportional system, although the 30 supplementary members would be elected on a somewhat similar basis to MMP.
 
MMP and maybe STV require a larger parliament than FPP, PV and SM.  A citizens-initiated referendum in 1999 indicated overwhelming support for a 99-seat parliament.  Despite this, the referendum is to be conducted on the basis that there will be 120 seats under all options.
 
The Rugby World Cup is drawing to a close.  It is time to focus on the most important contest of 2011, which is whether to change our voting system.
 
Roger Kerr is the executive director of the New Zealand Business Roundtable.  Check out his blog on www.nzbr.org.nz