MMP in NZ: An example of “best of both worlds” in action

In Shugart and Wattenberg (2001) we ask if mixed-member systems offer a “best of both worlds.” That is, do they allow simultaneously for the benefits of local representation and individual-member accountability that are the (supposed) advantages of single-seat plurality (FPTP) and the representation of smaller national parties that might struggle to win districts but would be represented under proportional representation (PR).

There was a question mark in the book’s subtitle. Over time, I have come to believe that indeed the proportional type (MMP) does have a strong tendency to offer the best of both worlds. The reason is that members elected in districts have incentives to behave as local representatives at the time that there is close approximation between party vote and seat shares (assuming compensation is carried out nationwide or in large regions). The majoritarian type (MMM, as in Japan and Taiwan) probably does not; it is much closer in its overall incentive structure to FPTP, even though it does indeed permit smaller national parties to win seats.

For MMP, the “best of both worlds” argument assumes that parties nominate dually–meaning many elected members will have run in a district and had a (realistically electable) list position simultaneously. If they do, then even the list-elected members will have a local base, and should have incentives to act as the local “face” of the party, including possibly by offering constituent services. Both prior anecdotes I have shared from New Zealand (e.g., “shadow MPs” who win from the list and maintain a local office) and my forthcoming coauthored book, Party Personnel, offer further evidence that MMP does indeed work in this way.

Now comes a terrific anecdote from New Zealand’s 2020 election. In this election, Labour won a majority of seats (64/120) with 49.1% of the nationwide party list vote. In the nominal tier of single-seat districts (electorates) it won 43 of the 72 available seats. Its win included some districts that are normally strongholds of the center-right National Party (which won 35 seats overall and just 26 districts).

Commenting on some of the Labour wins in mostly rural districts, Federated Farmers president Andrew Hoggard said:

in some “flipped” electorates Labour list MPs had worked hard to raise their profile and get involved with the community and this had paid off when they campaigned for the electorate.

This is an ideal description of how the “best of both worlds” argument works: list-elected members have incentives to attend to local needs of the district in which they ran for the nominal seat (but “lost”) in hopes of capturing the local plurality in the next election.

Of course, there were other factors at work as well. I will offer another planting about one of those factors separately. There is also some uncertainty at this stage just exactly the degree to which rural voters flipped, as the wins may have come in significant part from very large swings in the town areas within districts that also include large rural areas. Regardless, MMP offers the key advantage of giving most elected members, if dually nominated, a tie to a local constituency while ensuring close approximation of overall seat totals to party-list votes.

Why so much “high policy” in the LDP?

I am close(-ish) to finishing up a book on Party Personnel, coauthored with Matthew Bergman, Cory Struthers, Ellis Krauss, and Robert Pekkanen. The short version of what the book is about: How does the electoral system (and electoral reform) shape how parties deploy their “personnel” (i.e. elected legislators) to legislative committees to allow them to engage in activities that support the party organizational goal of seat-maximization?

(Quick note: While the book is coauthored, I should make clear that this post is just my musing about a puzzle, and not a piece of the book. Nor do my coauthors bear any responsibility for what I am writing here, or conclusions I attempt to draw.)

The outcome variable of interest in the Party Personnel project is the “type” of committee assignment a legislator receives–high policy, public goods, or distributive. This typology first appeared in Pekkanen, Nyblade, and Krauss (2006). In most of the countries covered in the book, a party typically has 50%-60% of its legislators sitting on high policy in any given term of parliament (not necessarily all at once, as members may be rotated). But, in Japan, the Liberal Democratic Party often has 75% or more on high policy, and in some years over 90%!

What explains the unusually high rate of high policy committee assignments in the LDP? I do not think we currently have a good explanation. We have floated some in internal discussions (mostly internal to my own brain), but as I will show in this post, they are not adequate. Before we get into trying to answer the question posed in bold at the start of this paragraph, let’s establish which committees are classified as high policy. These are committees charged with involvement in policies that are about the management of the economy and other matters of state–this is the sense in which they are “high”. Examples are finance, economy, budget, justice, defense, and foreign affairs.

Japan underwent a major electoral reform prior to the 1996 election. The old system was single non-transferable vote (SNTV). The post-reform system is mixed-member majoritarian (MMM). If we look only at averages by electoral-system era, it looks like a case of electoral reform resulting in a large increase in the percentage of LDP members of the House of Representatives obtaining high policy (HP) committee assignments:

SNTV era: 73% of legislators on HP.

MMM era: 86% of legislators on HP.

The difference in means when comparing eras is statistically significant. So, it is the electoral reform, right? (Never mind that even 73% pre-reform would be high, compared to other cases.) Is there a reason why MMM would lead a party to want to emphasize the experience of its caucus in HP more than would be the case under SNTV? Amy Catalinac‘s book, Electoral Reform and National Security in Japan (2016), suggests a reason why the answer might be yes. She analyzes individual candidates’ campaign manifestoes and finds that they are more likely to mention defense under MMM than they were under SNTV. The reason she gives is that members’ having a reputation for high policy areas like defense and foreign affairs was not useful under SNTV, when they were overwhelmingly concerned with “pork” for which they could get individual credit. By contrast, under MMM, each member is the sole standard-bearer in a single-seat district (and is often also running on a closed party list), and thus the pork incentive is greatly diminished. As national security is a key component of high policy, a similar effect might also account for the higher rate of HP committee assignments after electoral reform. That is, HP committees are assigned to LDP legislators at a greater rate under MMM because the party as a whole has a stronger interest in appearing credible on high-policy issues, including national security. This is one plausible explanation of the changes in era averages. For reasons I will turn to later, I am not satisfied with this attempt to explain the patterns in committee assignment.

An initial idea I had was that perhaps the high rate of HP, post-reform, is a legacy of a high rate under SNTV, and will be seen to have declined under MMM. In other words, this is a totally competing explanation to the one that could be derived from a logic similar to that of Catalinac. I would expect more delegation to the cabinet under MMM, in the sense of its being more Westminster-like than under SNTV. (This is a point that Catalinac explicitly argues, in justifying her disagreement with some Japan specialists who, upon the electoral reform, thought pork would remain just as important, only district-focused rather than more narrowly focused as under SNTV.) The problem with expecting a shift towards more HP committee membership under a supposedly more Westminster-like system, or just generally a more policy-centric system, is that it does not comport well with our comparative evidence.

We know that in two Westminster systems covered in the book, Britain and pre-reform New Zealand, the rate of HP committee membership is not especially high (30% in UK Conservatives, 33.5% in Labour; NZ National 54%, Labour 68%). All of these percentages are lower–most are much lower–than the MMM-era mean for the LDP. Nor is it high in Germany (near 60% in both major parties) or post-reform NZ (46% National, 57% Labour), our two MMP cases. These are all systems in which we expect party policy reputation to matter more than individual reputation. So, if Japan moves from SNTV, with its strong focus on the individual, to MMM, with greater focus on the party as a “team” seeking to take on (or hold on to) governing, why would HP be high under MMM?

With this as a puzzle, it seemed likely it might have been just a legacy of pre-reform SNTV. Perhaps, under SNTV, there actually is a logic to getting nearly everyone on HP because your electoral system makes everyone need to have a unique personal reputation. While this does, as noted, run up against the problem that the HP percentage is higher post-reform, it is worth entertaining why its being high under SNTV might not itself be inconsistent with the incentives of the system.

Why might HP for almost everyone be a strategy compliant with SNTV? Maybe the former SNTV system led the party to want most of its members to gain experience in high-policy areas because each member needs to be “his own party”. (Under SNTV, especially, LDP legislators have been overwhelmingly male.) This possible explanation seems at first to be in tension with common expectations that members under SNTV have to differentiate themselves, such as by credit-claiming for pork. Because votes are not pooled (or transferred) among co-partisans, the party needs a way to divide the vote efficiently in order to maximize seats. The literature on vote-division emphasizes how members need to be distinct from one another, so why have almost everyone on high policy?

Actually, this piece of the larger puzzle turns out not to be such a puzzle at all, even though it initially struck me as odd. Even if all legislators (2 or 3) from a given district are on HP, they can still differentiate by being on different HP committees (one on budget, one on defense, for example). Thus having many members on HP and having them develop their own personal reputations are not in any way contradictory. However, differentiating on sub-categories within HP may still not be as beneficial to claiming credit for things uniquely attributable to a specific politician as are pork-related benefits. A common expectation in the vote-division literature (including a key point of Catalinac’s thesis) is that pork is more useful for vote-division than high policy.

Even if we accept that HP is likely suboptimal for vote-division purposes, having everyone on HP does not preclude legislators also being on more specifically district-focused committees in the areas of public goods (e.g., health or education) or distributive (e.g., construction, agriculture, or transport). In fact, the LDP also has an unusually high rate (relative to other parties among the book’s cases) of category overlap. The average member is on about 1.6 of our three categories, unlike in most other countries where the figure is in the range of 1.2 to 1.4. In other words, by our categories, it is members in other countries that are the specialized ones. In the LDP, they are not; they are actually closer to being generalists, at least in this sense.

Having assignments in multiple categories allows each legislator to build a personal portfolio, almost like a micro-party, in which they are involved in some HP task and also frequently a task in either public goods or distributive during the same term. This kind of portfolio could be very useful for building the personal electoral coalition each individual needs to ensure election under an electoral system that pits members of the same party against each other in multi-seat districts, with no party-level vote-pooling. In other words, SNTV.

If the building of a personal portfolio, including but not limited to HP, due to SNTV incentives were the explanation, we should see a decline after the change to MMM. In the graph below, we will see that we do! So that is good. However, we still face the problem that it should not be higher on average during the era of MMM (so far) than it was during the era of SNTV. Yet that is precisely what we saw in the era averages shown above. Now, let’s disaggregate this thing called an electoral-system era. The graph shows the percentage on HP in each election from 1980 through 2009. The vertical line demarcates the eras, marking the first election under MMM.

The decline under MMM is certainly consistent with the notion that HP is less important to the individual legislator over time, given an electoral system that has eliminated intraparty competition in multi-seat districts. Additionally, the 1990 and 1993 elections show exceptionally high levels of personal portfolios including HP at the end of the SNTV era. Yet look how low the rate is before 1990. Thus, while we might be able to say that adaptation to MMM is leading to an expected decline in HP service after 1996 (albeit perhaps too slowly by 2009), we obviously should not conclude that it started so high because of SNTV! It was low under SNTV… until it was high. It then peaked in the first MMM election, before beginning a decline.

So what changed to lead the LDP suddenly to want nearly everyone to have high policy in their portfolio in 1990 and 1993? This–finally–is the question I am crowd-sourcing. The context of the 1990 election is one in which the LDP had just lost its majority in the second chamber (the House of Councillors). There was also a divisive debate at the time on enacting a national consumption tax, around the same time that real estate and stock market valuations were unsustainably high (leading to a subsequent period of economic stagnation). Also in 1993, due to splits over various issues including electoral reform, the LDP actually failed to win a parliamentary majority and found itself temporarily in opposition. How these would explain a surge in HP is not clear to me. So I am not proposing an explanation, but that is the context and perhaps points towards an explanation.

The pattern is similar if we look at category overlap. Again, this simply measures how many categories–out of high policy, public goods, and distributive–a member sits on. So, ignoring anyone who is on no committees in these categories (and I am ignoring such rare birds here), it can range from 1 to 3. The next graph shows this averaged across LDP legislators by election year. Again, the vertical line marks 1996, the first election under MMM. As we see, it is only 1990, 1993, and 1996 when the average number of committee categories per legislator approaches or exceeds 2.0. While lower in the other seven election, it is still above 1.5 in all elections except the three earliest SNTV elections in the sample (1980 through 1986) and then again in 2003 and 2009 of the MMM era. In the five just mentioned, it is between 1.3 and 1.4.

The pattern is again consistent with the LDP deciding for some reason before the 1990 committee allocations that it needed each member to have both high policy and at least one committee assignment from another category. After 1996, this category overlap becomes markedly less common (but still is higher than in most other parties we cover in the book).

A final graph breaks the HP category down and shows three of the main committees within it.

It is clear that the pattern of surging HP membership in 1990 is largely about the budget committee. More than half the party’s legislators sat on this committee in the legislatures elected in 1990, 1993, and 1996. The other two included here (economy and defense) show smaller bumps as well, just not rising as high. This again would be potentially consistent with my proposed explanation that “everyone needs a diverse portfolio under SNTV”, provided we can add a condition as to why this need is only actually realized at the end of the SNTV period and not the entire era. So, the electoral system explanation needs to be augmented by some political factor, like fracturing of the party and greater pressure from the opposition.

It is further worth noting that of all “high policy” committees, it is budget and economy that would have the greatest “pork” potential. While I would not want to reclassify committees dealing with such clearly aggregate national matters to the distributive category–they are clearly “high” topics–they do allow for opportunities to claim credit. Did the LDP simply need this even more in the 1990s than in the 1980s? The patterns certainly suggest they need it less under MMM, at least after the first MMM election of 1996. The patterns also show that defense committee assignments very quickly went back down in the 2000s after their peak with the first MMM election. So, while they may continue to talk about national security in the individual campaign manifestoes (per Catalinac), few LDP members by 2009 are sitting on committees where they can actually be involved in such policy discussions.

This has been a long post. Thank you to anyone who made it this far! I hope someone has some suggestions for why these patterns are seen in the data. The book does not look at time factors in committee assignments, except for pre-reform and post-reform eras where there has been a change of electoral system (Japan and New Zealand, among our cases). However, any attempt to explain the anomalously high averages in high policy assignment and committee-category overlap in Japan has to grapple with the fact that there is a within-era variance in the LDP that is quite stark. It is not just a story about two different electoral systems, nor is it something immutable about the LDP.