The main theme of this book is that particular electoral systems do not invariably have the same consequences for the nature of the party system. Moreover, this variation is not random or dependent upon sui generis features of each country; rather, when it comes to the relationship between electoral system and party system, there is a systematic difference between established democracies and new democracies.

The focus is upon mixed systems: those in which a proportional number of seats are filled by plurality rule in single-member districts (SMDs), and the rest by proportional representation (PR) using party lists. Outcomes in the SMD component are compared and contrasted with those in the PR component. Maurice Duverger theorized that SMDs are likely to “constrain” the number of parties to a maximum of two, whereas with seats filled by PR in multimember districts, the reduced incentive to strategic defection increases the likelihood of a multiparty system. Robert G. Moser and Ethan Scheiner argue that such expectations tend to hold in established democracies, but generally do not in new democracies.

Chapter 4 demonstrates that SMDs do indeed constrain the number of parties to a greater extent in established democracies than in new democracies, while Chapter 5 shows that there is evidence of strategic defection in the SMD tier in established democracies such as Germany, New Zealand, and Japan, but not in new democracies such as Lithuania, Russia, and Ukraine. Chapter 6 finds that a theory from Gary Cox’s 1997 Making Votes Count seems to hold in established democracies but not in new ones.

The impact of political context, Moser and Scheiner argue, is seen not just in terms of the resulting party system but also in other political outcomes. Conventional wisdom holds that PR is more conducive to female representation in parliament than SMD-based systems but, again, they conclude that this is true only in established democracies (Chapter 8). And in Chapter 7, they assess the relative impact of social diversity and electoral systems upon the number of parties, concluding that the former plays the decisive role: Social diversity affects the number of parties under all electoral systems. However, the measures of “social diversity” appear arbitrary, without any evidence that the cleavage employed is politically salient, and are not consistent across countries. In New Zealand, the measure is the proportion of Maori in each constituency, though the total Maori strength is only about 15% of the country’s population, while in Wales, language is taken as the key signifier, though this is hardly an “ethnic” factor. In Japan, the degree of urbanization is used, though it is not clear what kind of diversity that is intended to measure (ethnic? linguistic? religious?), let alone whether it is a satisfactory proxy for it. The authors acknowledge (p. 202) that “ethnic diversity is . . . not necessarily equal to the important social cleavages that really divide a polity.”

The analysis is solid, and the focus on the constituency (district) level is commendable, given that many of the theories about the likely impact of electoral laws really apply at that level, even though they are often tested with national-level data. Readers might have less doubt about the validity of most of the findings than about their significance. What, exactly, is new here?

Although the conclusion that particular electoral systems do not always produce identical party systems is presented as running contrary to conventional wisdom, this is never established. We are told (p. 11) that “Constitutional engineers who presume that electoral systems will have the same effects in every context will be sorely disappointed,” but no evidence is supplied that anyone has ever held such an implausible belief. Virtually no one coming to the study of electoral systems and party systems can fail to have noticed that the party systems of the United States, Britain, and India are very different, for example, even though all use the single-member plurality electoral system. The authors acknowledge that some readers might indeed feel that they “overstate the deterministic nature of the social science conventional wisdom that [they] critique” (p. 40), but having raised the point, they do not rebut it. Without examples of the electoral-system determinism claimed as currently representing conventional wisdom, it would be optimistic of Moser and Scheiner to expect their argument to be hailed as a new perspective on electoral systems.

Some of Duverger’s statements, if taken out of context, might appear to approach such determinism, but a close reading of Duverger shows awareness on his part of the range of factors that shape a party system. He also raises an idea not discussed at all here, namely, that electoral systems, far from being the “cause” of party systems, may be the dependent variable in the relationship. That is, electoral systems may be chosen to suit existing party systems, or at least the dominant actors within them, rather than to create those party systems. This line of thought, developed further by Josep Colomer in his writings on electoral system choice (not cited here), is never considered, the assumption always being that the direction of causality runs from electoral system to party system.

A number of factual errors might have been cleared up prior to publication. Women’s election rates under closed-list PR and from SMDs are compared (pp. 217–18), but Lithuania, one of the cases included, used open lists rather than closed lists during the period covered. The threshold for proceeding to the second round in French parliamentary elections is 12.5% of the electorate, not of the votes (p. 87). The number of überhangmandate in Germany, far from being typically “relatively low” (p. 65), reached levels so high by 2009 that they rendered the electoral system unconstitutional as it stood. Ghana is twice said (pp. 29, 251) to have something close to a single-party system, but in fact it has an archetypal two-party system.

Finally, although the book repeatedly contrasts outcomes in “established democracies” and “new democracies,” the latter concept remains nebulous. If “newness” is the key criterion, then it is easily measurable—though presumably the quality of newness has a finite lifespan. (For how much longer will Hungary remain a new democracy, for example?) At other times, as when female representation is discussed, patterns in established democracies are compared with those in postcommunist states, as if postcommunism, rather than newness per se, is the important factor. And in the Conclusion, the basis of comparison seems to change again to the nature of the party system; for example, “we find that countries with poorly institutionalized party systems and a lack of democratic experience were struck by substantial party proliferation at the district level in SMDs” (p. 244). Using a poorly institutionalized party system as a factor reducing the probability that a single-member plurality electoral system will result in a two-party system comes dangerously close to tautology; the missing condition (a strongly institutionalized party system) is all too similar to the nonappearing value of the dependent variable (a two-party system).

Electoral Systems and Political Context calls attention to the value of drawing systematic comparisons between the single-member constituency and the list components of mixed electoral systems, and of basing analysis at the constituency level. It raises interesting questions for further research, and even if some of the claims it makes for itself are overstated, it is sure to be cited by future work in this field.