District magnitude, the number of seats per district, is a critical component of electoral systems. It affects key outcomes such as accountability, legislative fragmentation, and disproportionality in representation by providing incentives for voters, candidates, and representatives. Some democracies have identical-magnitude districts (whether under majoritarian or districted proportional representation), yet many elect their representatives through districts of varying magnitudes. Thus, in cross-country analyses, researchers first come up with a summary score of district magnitudes per country. This is often considered merely a mechanical, pre-analysis step of preparing the data. We show that the national score of district magnitude is a thorny business, consequential for inference on substantive questions. Specifically, different conceptualizations and measurements of district magnitude lead to different scores, and those, in turn, may both mischaracterize countries and lead to different inferences. Moreover, the status quo in the measurement of district magnitude – equally weighing all districts – is often misleading, and the problem is compounded by within-country variation in magnitude and malapportionment, common in Europe and Latin America, respectively. We propose two alternative measures of district magnitude – weighing districts by the share of representatives or voters in them – and provide guidance on the circumstances under which each measure should be utilized. Our analysis has implications for how this key component of electoral systems should be conceptualized, measured, and employed in cross-country analyses.

While institutional theories of party system size are usually examined cross‐nationally, there is ample reason to expect that changes in electoral institutions will affect party system size within countries as well. Although some of this effect may occur immediately, most of the effects are likely to be realised over time and across subsequent elections. A series of error‐correction models examine the short‐ and long‐term effects of changes in electoral institutions on party system size. The results indicate that changes in electoral institutions do produce the expected effects on party system size, and that these effects occur mostly over the long term.

In electoral systems with districts that vary in magnitude, the number of seats to be filled in each district will be even or odd. We argue that such a variation has crucial political consequences, called the ‘odd–even effect’. In low‐magnitude districts, elections are more competitive when the district magnitude is odd than even; the incentives for coordination are thus stronger in the former scenario than in the latter. Employing quasi‐experimental data from 780 districts in Spain's lower house elections, we show that the number of parties is smaller in low‐magnitude districts with an odd number of seats than in low‐magnitude districts with an even number of seats. The elite‐ and voter‐level mechanisms driving the odd–even effect are examined using data on mobilisation efforts and wasted votes at the district level.

It is well known that different types of electoral systems create different incentives to cultivate a personal vote and that there may be variation in intra‐party competition within an electoral system. This article demonstrates that flexible list systems – where voters can choose to cast a vote for the list as ordered by the party or express preference votes for candidates – create another type of variation in personal vote‐seeking incentives within the system. This variation arises because the flexibility of party‐in‐a‐district lists results from voters' actual inclination to use preference votes and the formal weight of preference votes in changing the original list order. Hypotheses are tested which are linked to this logic for the case of Belgium, where party‐in‐a‐district constituencies vary in their use of preference votes and the electoral reform of 2001 adds interesting institutional variation in the formal impact of preference votes on intra‐party seat allocation. Since formal rules grant Belgian MPs considerable leeway in terms of bill initiation, personal vote‐seeking strategies are inferred by examining the use of legislative activity as signalling tool in the period between 1999 and 2007. The results establish that personal vote‐seeking incentives vary with the extent to which voters use preference votes and that this variable interacts with the weight of preference votes as defined by institutional rules. In addition, the article confirms the effect of intra‐party competition on personal vote‐seeking incentives and illustrates that such incentives can underlie the initiation of private members bills in a European parliamentary system.

This paper examines how public demand and institutional contexts shape the substantive representation of LGBTQ+ populations across Europe. I argue that while positive social constructions of LGBTQ+ populations are a necessary condition for the advances of LGBTQ+ rights, issue salience can facilitate LGBTQ+ rights only if public opinion on LGBTQ+ is positive. Furthermore, I assert that translating social constructions of LGBTQ+ populations into policy outputs is mediated by the proportionality of electoral systems. I analyze policy scores, public attitudes, and online interest concerning LGBTQ+ topics. I find that positive social constructions are correlated with more inclusive LGBTQ+ rights across countries, and the positive impact of issue salience on LGBTQ+ rights is observed only in countries with positive social constructions. Additionally, the analysis of electoral systems provides mixed evidence regarding the role of proportionality.

While recent research on the origins of proportional representation (PR) in Europe has focused on domestic political explanations, we bring international trade back as an economic explanation for the politics of electoral system choice. Spurred by Rogowski’s (1987) theory of the trade origins of PR and the political economy literature on trade policy, we argue that political conflict over trade shaped the struggle over electoral reform during the first globalization. Because tariffs were a central and contested issue, economic interests hurt by rising tariffs under the old electoral system had economic motives to support the introduction of PR. To test this theory, we leverage district-level popular votes in Switzerland using a within-country research design. We find support for the core mechanism of the trade theory: demand for protectionism entailed stronger opposition to the introduction of PR. Using panel data, we demonstrate that changes in the relative size of the agricultural sector, the central pillar of support for protectionism, were closely related to changes in support for PR. We also examine legislative voting in Germany and find that protectionism was linked to subsequent opposition to electoral reform. Altogether, our analysis highlights the neglected importance of trade in conflict over electoral institutions.

This article investigates determinants of candidate turnover in 10 European established democracies with list-PR electoral systems. We identify party and election variables that affect the supply and demand of new candidates on the parties’ lists. In addition, we apply a weighted candidate turnover measure to investigate the dynamic of renewal on high-ranked list positions. We built an original dataset that contains 3344 electoral lists of represented political parties. Hypotheses are tested by means of a multilevel analysis of political party list renewal rates. At the party level, leadership change and larger party size in terms of members are found to coincide with higher general turnover. At the system level, general turnover is higher in elections with closed lists and high electoral volatility. At higher positions on the list, candidate turnover appears not to be affected by the party- and system-level variables identified in the broader literature.

Previous studies had no consensus on whether a ‘mandate-divide’ exists between district and party-list legislators under the mixed-member system. I argued that previous studies ignored the role of the party. This article aims to explore the legislative consequences of the 2005 electoral reform and the role of parties in Taiwan. I analyzed the roll-call votes, considering abstention and absence as potential defection, along with interviews. The data cover from the fifth to eighth Legislative Yuan, two periods each before and after the electoral reform. The findings show that district legislators tended to defect from the party line than list proportional representation (PR) members in pre- and post-reform periods. However, district legislators only tended to be absent from the voting than list PR members after the electoral reform. Mandate-divide was present throughout the period, but differences were more salient before the reform. Besides, evidence stressing the influence of parties was revealed in the interviews. Party leaders enforce various punishments to enforce party discipline. The role of party became more important after the electoral reform. District legislators have higher absence rate after the electoral reform because they need to engage more in constituency service or avoid expressing their position on controversial issues. The ruling party tends to sanction the absence when they have majority in parliament.

This paper shows how an uneven electoral system in Japan shapes political parties' mobilization strategies by utilizing a majoritarian electoral system with heterogeneous district magnitudes, which in turn contributes to the gap in turnout across districts. Scholars have long debated the relationship between electoral systems and turnout; it is known that countries with proportional representation electoral systems – those with larger district magnitude – tend to have higher turnout rates than countries with majoritarian electoral systems, especially single-member district (SMD) systems. The current discussion on turnout and district magnitude of an electoral system assumes a monotonic relationship between these factors: the larger the district magnitude of the electoral system, the more (or less) participatory the electorate, due to competitiveness and mobilization efforts by political parties and other relevant groups. In contrast, this paper shows a mixed relationship between district magnitude of the electoral system and party mobilization and subsequent turnout, investigating a majoritarian electoral system with uneven district magnitude in the Japanese Upper House. During the survey period, the party system in Japan consisted of two major parties and a few smaller parties; consequently, the two major parties focused their efforts on SMDs in order to maximize their seat share, while smaller parties focused their resource on districts electing more than two members (where they have some chance to elect their party's candidates). In combination, these party strategies have resulted in the lowest mobilization and turnout rates in districts with two members.

As the first country to introduce proportional representation (PR), Belgium has attracted considerable attention. Yet, we find the existing explanations for the 1899 breakthrough lacking. At the time of reform, the Catholic Party was politically dominant, advantaged by the electoral system, and facing reformist Socialists. Nevertheless, they single-handedly changed the electoral system and lost 26 seats in the first election under PR. We argue that the Catholics had good reasons to adopt PR. Majoritarian rules tend to create high levels of uncertainty because they provide incentives for non-dominant parties to cooperate. Such electoral coalitions are facilitated by multidimensional policy spaces that make electoral coalitions other than between nonsocialist parties possible. PR reduces the effectiveness of cooperation between non-dominant parties, but such certainty comes at a price. In addition, in the presence of dominant parties, divisions over electoral system reform often result in intra-party conflicts that may be more decisive than inter-party conflicts.

The staggered renewal of parliamentary mandates is widespread in upper chambers, yet little understood. Comparative work has found that all members of a chamber are affected by upcoming elections, not merely those whose terms are up for renewal. In this study, we explore for which activities, and under which conditions, staggered membership renewal is associated with class-specific parliamentary activity, defined as systematically differing behaviour across two or more classes of members. We examine these questions with data on the French Senate. Drawing on insights from the study of political business cycles, legislative cycles, and previous scholarship on staggering, the article shows that behaviour varies over the course of senators’ mandates, and that class-specific behaviour exists. However, staggering produces a different pattern of parliamentary activity than might be expected: proximity to elections reduces parliamentary activity of the class of senators facing re-election; by contrast, senators ‘not up next’ become more active. This effect, we argue, reflects the electoral system under which senators are elected.

This article examines the effects of electoral systems on issue ownership. This study argues that electoral rules significantly affect issue ownership because they prompt candidates to adopt different types of electoral campaigns. Compared to the single non-transferable vote (SNTV) system, the mixed-member majoritarian (MMM) system prods candidates to change the pattern of electoral campaigns from candidate-centred to issue-centred competition. In particular, partisan issue effects are more effective in gaining votes under the MMM. To support the argument, I find evidence from content analyses of party manifestos and multinomial logistic regression models of electoral surveys between the pre-reform and post-reform elections in Japan.

The directly elected representatives to Hong Kong's Legislative Council are chosen by list proportional representation (PR) using the Hare Quota and Largest Remainders (HQLR) formula. This formula rewards political alliances of small to moderate size and discourages broader unions. Hong Kong's political leaders have responded to those incentives by fragmenting their electoral alliances rather than expanding them. The level of list fragmentation observed in Hong Kong is not inherent to PR elections. Alternative PR formulas would generate incentives to form broader, more encompassing alliances. Indeed, most countries that use PR employ such formulas, and the most commonly used PR formula would generate incentives opposite to HQLR's, rewarding broader electoral alliances rather than divisions.

Carey and Hix (2011) propose that a proportional electoral system with a moderate number of seats per district offers the best compromise between (1) accurate representation and (2) strong accountability. The argument is that there is a district magnitude (DM) level where the trade-off between proportionality and fragmentation of parties is optimal. This DM is called the sweet spot. We explore this proposition through lab experiments conducted in Brussels and Montreal. We find that the probability of achieving a “good” outcome on both proportionality and the number of parties is slightly higher at moderate DMs. We note, however, that this probability remains low.

During the five democratic elections held in Taiwan from 1992 to 2004 inclusive, the formerly dominant Kuomintang Party (KMT) was temporarily supplanted by the Democratic Progressive Party (DPP) as the nation's largest political party. Most explanations for this have focused on party fragmentation and the changing patterns of electoral competition it helped create. These are important factors, but they have not been tested empirically at the level where candidates won and lost legislative seats, the level of the election district. This article offers such an empirical test, and it will show that these two factors had a direct impact on the ability of DPP and KMT candidates to obtain legislative seats. We also show that these factors carried indirect impacts by hurting the ability of the KMT and DPP to nominate in a way that they would obtain all the seats that their obtained vote shares would allow.