MMP Review: My 2c

Only one day left to put in your MMP Review submissions. Here is one I prepared just now.

In the spirit of earlier large-scale nerdery by electoral system-enamoured-online-commentator-folk, here is my submission to the MMP Review. "Enjoy."


1          Introduction

1.1           This submission is from Rob Salmond. I am an Assistant Professor of political science at the University of Michigan, and have authored multiple academic articles on New Zealand elections and on the impact of electoral systems on politics.

1.2           Because I am currently based in the US, I am not available to speak personally to this submission.

1.3           This submission addresses the matter of the thresholds for allocation of seats.


2               The party vote threshold

2.1           As a matter of principle, I favour the lowest possible threshold consistent with good government in New Zealand, because proportional elections should lead to proportional outcomes unless there is very good reason to do otherwise.

2.2           I note that a number of other submitters have expressed concern that if the party vote threshold drops below either 5% or 4%, then the result could be fragmentation of the New Zealand party system leading to increased political instability that ultimately stands in the way of effective government. In almost all cases, this claim is made as an assertion, without much evidence. When evidence is produced, it is often in the form of a supposedly exemplary case, such as Israel or Italy.

2.3           There is not rigorous evidence to support the claim that a lower threshold is likely to lead to instability in New Zealand.

2.4           To look for such a relationship, I used data from the University of Berne on the number of changes in the makeup of a government that happen each year in the OECD, a good measure of government instability. I combined these data with Arend Lijphart’s data about the national-level legal thresholds and effective thresholds for party representation. The total number of countries under examination is 23 and the total number of country years is 826. The chart below shows that there is no obvious relationship between the threshold for party representation and instability in government, either in all years or in non-election years.

2.5           Further analyses show there is not a statistically significant relationship between the threshold for party representation and the level of government instability, measured using annual changes in government composition. For the technically-minded: simple bivariate correlations between thresholds and instability in PR countries were only significant at 0.514, and this significance drops further to 0.952 if election years are discarded from the analysis to give an estimate of between-election instability. In non-technical terms: for every unstable low-threshold country like Israel, there is a stable low-threshold country like the Netherlands (where there were only thee between election changes in government composition over almost forty years).

2.6           The data do show, however, true that as the number of political parties goes up, instability also tends to rise. And it is also true that decreases in the threshold tend to increase the number of parties. What, then, explains the lack of a relationship between the threshold and instability?

2.7           The answer is that many things other than the electoral system threshold cause the number of parties to rise and fall, and some of those other reasons are also causal of government instability. Religious fragmentation, for example, frequently causes the number of political parties to rise and is also an indication of a divided society, often linked to government instability. Multi-ethnic societies have the same issue.

2.8           These relationships can jointly give the misleading impression that the number of parties is a prime cause of instability, whereas in fact deeper divisions in the community are causing both more parties and more instability at the same time. The parties-instability correlation is likely spurious.

2.9           As a result, I recommend a substantial lowering of the party vote threshold, down to 2% at most.


3               Electorate seat thresholds

3.1           Like the majority of submitters, I favour abolishing the rule that allows parties full proportionality if they win one electorate seat.

3.2           These so-called “electorate lifeboat” rules are often designed to protect the interests of regional parties that have deep appeal to a small, regionally concentrated proportion of voters. In the New Zealand case, such regional parties have seldom emerged. Indeed, where parties really are successfully targeting a narrow slice of voters – for example the Maori Party and Mana – our experience is that these parties have done well enough in electorate contests not to need any list seats to achieve proportionality. Put simply, the problem that this rule was designed to solve has simply not arisen.

3.3           Instead, the rule is protecting the interests of some parties that seek broad nationwide appeal, but that fail to win more than a couple of percent support. I think it is hard to make a normative case why a party with 3.7% support including an electorate seat (ACT in 2008) should receive five seats in Parliament while a party with higher party vote total but no electorate seats (New Zealand First in 2008) should receive none. If this kind of anomaly were the cost of protecting a vibrant set of parties representing small, otherwise-easily-forgotten regions of the country, then we would have to seriously consider the appropriate tradeoffs. But at the moment we have the anomalies without the resulting benefits, which is very hard to defend.

3.4           Further, the issue of inadequate representation for a sub-5% party with an electorate seat will become less important if the 5% threshold is lowered, as I recommend.