In keeping with Duverger's research, some scholars have explored the relationship between electoral systems and the number of political parties from a comparative empirical perspective. However, few of them have provided explanations for the question of how Japan and Taiwan, two countries that have experienced similar reforms, obtained different outcomes. While both Taiwan and Japan transitioned from similar single non-transferable vote (SNTV) to mixed-member majoritarian (MMM) systems, the speed with which the two countries moved toward two-party systems, and the actual number of parties in their legislative bodies, significantly vary. Though some works have noticed that the presidential system does decrease the number of parties in the legislature, the question needs to be explored further. This book, which I highly recommend, discovers the missing link between electoral systems and constitutional systems, and bridges the gap between them by putting forward a new perspective-executive-centric theory. The authors of the book have provided solutions to the puzzle by looking into how contextual factors mitigate the effect of electoral setups on party systems.
The book relies heavily on the comparison between Japan and Taiwan, and excellently displays the effect of constitutional design on a party system under similar MMM setups. Part I of the book presents key contextual elements in Japan and Taiwan. In particular, the role of the party in defining portfolio allocation under different constitutional systems is intriguing. In Chapter 2, Lin points out that the role of political parties in portfolio allocation is suppressed under unicameral semipresidential constitutions, while political parties play a decisive role in cabinet formation in parliamentary systems. The difference between the two constitutional systems is also reflected by small parties gaining more bargaining power in bicameral, parliamentary systems than in presidential ones. One of the interesting findings here is that the electoral system exerts influence on the partisan formation of cabinets in Taiwan and Japan. The effect of MMM systems in reducing the number of ministers from the president's party in Taiwan is not obvious because of the preference for appointing non-partisan scholars and civil servants as ministers. However, Japan's MMM system does increase the number of parties in the cabinet in Japan (pp. 52–72). This can be explained by the need for cooperation from small parties, especially when the prime minister cannot control the upper house.
The abovementioned findings are echoed by Nemoto and Tsai in Chapter 6, which addresses post allocations and pre-electoral coalitions under the MMM systems of Japan and Taiwan (pp. 165–91). Constitutional design does cause different effects on pre-electoral coalitions under the same MMM system. The parliamentary system and bicameralism explain why small parties have greater influence in Japan than in Taiwan. Big parties in parliamentary and bicameral systems need small party cooperation to pass confidence votes and for consensus in the upper house
The authors leave room here for readers to ponder why the president chooses to appoint his own people inside the party rather than choose the right talents under the SNTV system, as the authors of the chapter point out. Chen Shui-bian is put forward as an example. This seems different from Lin's findings in Chapter 2 that Chen appointed non-partisan members to his cabinet to counter the major opposition parties in the legislature. Furthermore, it would be interesting to explore further the average proportion of cabinet members from the prime minister's own party and others in Japan.
The factional politics of Japan and Taiwan are one of the highlights of the book. While the MMM system has significantly reduced the importance of factions, they continue to exist for personnel management under the parliamentary system in Japan. Batto and Huang properly explain the counter-intuitive phenomenon that electoral reform has little effect on factional politics in Taiwan. Factions in Taiwan are locally rooted and the MMM system has pushed factional politics toward bifactionalism, rather than elimination. Local executive seats, thus, are much more important for factions in Taiwan.
Part II of the book moves beyond Japan and Taiwan to other countries that have adopted mixed member electoral systems, including Thailand, the Philippines, New Zealand, Bolivia, and Russia. Some of the contextual factors that mitigate the effect of electoral systems are highlighted. Limiting the president to one term discourages presidential candidates from building nationalized parties in the Philippines (pp. 229–46). An example of an alternative means of deriving proportional seats is New Zealand, which is characterized by more and smaller parties than in Germany, as is made clear by Shugart and Tan (pp.247–77). That SMD seats in New Zealand can be translated into proportional seats regardless of the fact that the threshold for party votes makes its party system differ from countries adopting similar mixed member proportional (MMP) systems. Party institutionalization has been put forward as an important variable by Batto, Kim, and Matukhno in investigating blank votes in Bolivia and Russia. They found the contamination effect of presidential elections to the legislative election is constrained by the level of party institutionalization.
Methodologically speaking, this book has successfully demonstrated how the comparative approach achieves a high quality of research output and provides answers to the questions of political science. The congruent theme – the executive-centric approach – has permeated this edited volume. Each chapter is well connected to the others through allusions to key findings.
This book is definitely a classic on mixed member electoral systems. It also provides insights for exploring the topics of related research. For instance, while Japan and Taiwan experienced similar electoral reform, why is it that the programmatic turn of political parties happened only in Japan? What is the difference in policy-making processes under the influence of different contextual factors related to party system?
Recent social movements seem to have led to the convergence of Taiwan and Japan's political institutions in terms of lack of political opportunity under majoritarian-leaning electoral systems. These are questions that are left over for pundits and politicians who are attracted by the book's main theme.
