Political cleavages are often understood as deriving from either deep-rooted social divisions or institutional incentives. Contemporary Northern Ireland provides a test of the mutability of apparently entrenched cleavages to institutional change. Research undertaken before the ceasefire in the 1990s found noticeable asymmetries in the patterns of cleavage within the unionist and nationalist blocs. Within the unionist bloc, economic ‘left–right’ issues formed the main ideological division between the two major unionist parties. This contrasted with an ethno-national source of ideological division between the two nationalist parties. However, the emergence of a consociational form of government structure since then has demonstrated the ability of institutional incentives to reform some aspects of party competition swiftly. As evidence of this, we show that between 1989 and 2004 there was little change in the sources of support for Sinn Féin relative to the SDLP, but the influence of left–right ideology within the unionist bloc was negated as the influence of ethno-nationalism dramatically increased.

Why do new parties continue emerging and attracting votes in new democracies? Does the duration of the democratic regime facilitate party system stabilization? With original data on legislative elections in fifteen East European countries (1990–2004), this article shows that new party entry is more likely when the cost of entry is low, the benefit of office is high and the perceived level of electoral viability is high. Support for new parties is influenced by the extent of disappointment with existing parties. Further, while the number of new parties decreases gradually as democracies age, the support for new entrants follows no clear unidirectional pattern across time.

Advocates of proportional representation (PR) often cite its potential for increasing citizen involvement in politics as one of PR's fundamental advantages over plurality or first-past-the-post systems. The assumption is that plurality electoral systems distort the translation of votes into seats, discouraging and alienating small party supporters and other political minorities. In contrast, PR systems are believed to provide greater opportunities for representation which are assumed to instil greater efficacy and increase participation. We examine this theory linking institutions to electoral participation across a diverse set of countries using data from the Comparative Study of Electoral Systems. Using a multi-level approach we find evidence consistent with the expectations about the negative influence of disproportional systems on political minorities. Voters are also likely to have stronger partisan preferences in PR systems, which enhances political efficacy and increases voter participation. The effects of PR, however, are not all positive; broad coalitions, which are likely to be a feature of these systems, reduce political efficacy.

This article examines party discipline and party cohesion or defection, offering as an illustration the rebellion over postal privatization in 2005 by members of Japan's Liberal Democratic Party (LDP). It explores the importance of party rules – especially the seniority rule and policy specialization for district rewards – as intervening variables between election rules and party defection in a decentralized and diverse party. It is argued that in such cases, party rules like seniority can help prevent defection. When these rules are changed, as in the postal case of 2005, defection is more probable, but it is found that the relationship between defection and seniority is likely to be curvilinear, and also that the curvilinearity is conditional upon each legislator's having different incentives for vote, policy and office.

Variance in how citizens interact with the political world constitutes one of many classes of individual difference. Understanding the antecedents of this variance is the central objective for students of political behaviour, and researchers draw on numerous factors in addressing this task. Unfortunately, one potentially vital factor, personality, has received only sporadic attention in recent decades. Neglect of personality was understandable for many years, as psychological research on personality failed to produce concise taxonomies applicable to the study of politics. As the present analysis demonstrates, however, this situation has changed. Research on personality has gained new footing with the emergence of a series of five-factor models, and these frameworks hold great potential for the study of political behaviour. This thesis is advanced in a two-part analysis. First, we outline how and why our understanding of citizen politics may be improved through application of five-factor models of personality. In doing so, we focus on the components of one specific taxonomy, the Big Five lexical model. Secondly, using three datasets, we explore the link between the Big Five personality factors and a wide array of political attitudes and behaviours. Results reveal that all facets of personality captured by the Big Five framework matter for citizen politics, and that personality effects operate on virtually all aspects of political behaviour. These findings demonstrate the insight that can emerge with further application of broad-scale models of personality.

Social networking has a powerful influence on voters, but we do not know enough about the mechanisms of network influence. Recent research shows that one network member's influence is highly dependent on the others in the network, i.e. autoregressive. I test whether the influence of social network political knowledge is also autoregressive. I show that a strong predictor of vote choice similarity is the level of knowledge of the discussant, but greater knowledge of the other network members lessens dyadic agreement. Data from the American National Election Study collected in 2000 show that in the presidential election of 2000 having a knowledgeable discussant increases the chance of vote similarity with that discussant by 5 percentage points, but vote similarity decreases by 10 percentage points for each level of residual network knowledge. This research confirms the autoregressive influence of social network political knowledge.

Traditional explanations of the origins of regional parties as the products of regionally-based social cleavages cannot fully account for the variation in regional party strength both within and across countries. This unexplained variance can be explained, however, by looking at institutions, and in particular, political decentralization. This argument is tested with a statistical analysis of thirty-seven democracies around the world from 1945 to 2002. The analysis shows that political decentralization increases the strength of regional parties in national legislatures, independent of the strength of regional cleavages, as well as of various features of a country's political system, such as fiscal decentralization, presidentialism, electoral proportionality, cross-regional voting laws and the sequencing of executive and legislative elections.

This article discusses whether candidates and campaigns in US House elections condition the influence of national political tides by magnifying their effects at the local level. Using election returns, it is shown that this interaction effect is quite small: a positive national tide increases votes for weak candidates almost as much as strong ones. However, competition and national tides in US House elections do interact to produce turnover: high-spending challengers rarely win without the help of a national tide. Contrary to many accounts in the American politics literature, it is also found that the tide's influence is weaker in open seats in certain important ways. Together, these findings suggest that US House candidates benefit from national tides but have a limited ability to create them, and that the prospects for national responsiveness are hurt by the trend towards heavier competition in open seats.

In a recent article, Rogowski and Kayser introduced a claim to the political economy literature that majoritarian electoral systems: (a) systematically privilege consumers relative to producers and, consequently, (b) reduce real prices. The authors, modifying an established model of regulation, showed that, within a competitive political system, politicians favour those who provide only votes (consumers) over those who provide both money and votes (producers). When producers provide only money, the intuition becomes apparent even without a model: politicians respond more to voters under (majoritarian) systems in which a small change in vote share can produce a large change in seat share. Cross-sectional evidence for the OECD (Organization for Economic Co-operation and Development) countries in 1990 was strongly supportive, suggesting that real prices were, all else equal, about 10 per cent lower in the averageOECDcountry with single-member district (SMD) electoral systems than in those that used some form of proportional representation (PR).

As with all new empirical claims, healthy scepticism is warranted. Indeed, recent research in related areas has to be contrasted with – but it has not contradicted – these price results, associating proportional electoral arrangements with more positive social welfare outcomes including (a) less income inequality, (b) higher public spending, or, in combination with central banking institutions, (c) greater price stability. We acknowledge the possible incongruity of these results with those of Rogowski and Kayser; after all, verification of the price effects would suggest a more complicated relationship between electoral institutions and social welfare than is indicated in the extant literature.

In recent years some of the best theoretical work on the political economy of political institutions and processes has begun surfacing outside the political science mainstream in high quality economics journals. This two-part article surveys these contributions from a recent five-year period. In Part I, the focus is on elections, voting and information aggregation, followed by treatments of parties, candidates and coalitions. In Part II, papers on economic performance and redistribution, constitutional design, and incentives, institutions, and the quality of political elites are discussed. Part II concludes with a discussion of the methodological bases common to economics and political science, the way economists have used political science research, and some new themes and arbitrage opportunities.

In recent years some of the best theoretical work on the political economy of political institutions and processes has begun surfacing outside the political science mainstream in high quality economics journals. This two-part article surveys these contributions from a recent five-year period. In Part I, the focus was on elections, voting and information aggregation, followed by treatments of parties, candidates and coalitions. In Part II, papers on economic performance and redistribution, constitutional design, and incentives, institutions and the quality of political elites are discussed. Part II concludes with a discussion of the methodological bases common to economics and political science, the way economists have used political science research, and some new themes and arbitrage opportunities.

A widespread turn towards mechanism-centred explanations can be viewed across the social sciences in recent decades. This article clarifies what it might mean in practical terms to adopt a mechanismic view of causation. This simple task of definition turns out to be considerably more difficult than it might at first appear. The body of the article elucidates a series of tensions and conflicts within this ambient concept, looking closely at how influential authors have employed this ubiquitous term. It is discovered that ‘mechanism’ has at least nine distinct meanings as the term is used within contemporary social science: (1) the pathway or process by which an effect is produced; (2) an unobservable causal factor; (3) an easy-to-observe causal factor; (4) a context-dependent (bounded) explanation; (5) a universal (or at least highly general) explanation; (6) an explanation that presumes highly contingent phenomena; (7) an explanation built on phenomena that exhibit lawlike regularities; (8) a distinct technique of analysis (based on qualitative, case study, or process-tracing evidence); or (9) a micro-level explanation for a causal phenomenon. Some of these meanings may be combined into coherent definitions; others are obviously contradictory. It is argued, however, that only the first meaning is consistent with all contemporary usages and with contemporary practices within the social sciences; this is therefore proposed as a minimal (core) definition of the concept. The other meanings are regarded as arguments surrounding the core concept.

Can the positive impact of non-partisan ‘Get Out the Vote’ (GOTV) campaigns be generalized to a variety of institutional and cultural contexts? Gerber, Green and colleagues tested for the effects of these campaigns in a series of pioneering field experiments, which show that a face-to-face contact from a non-partisan source, carried out by a field force calling at the homes of citizens seeking to persuade them to vote, can increase voter turnout. Further experiments find that telephoning has an impact ranging from ineffective to positive, depending on the nature of the call; and there are positive, if weaker, results for other forms of intervention, such as door postings and leafleting; none for e-mail; and weakly positive or null impacts from rote telephoning. Many of these results derive from single cases or from a limited number of research sites; however, the culmination of these findings allows political scientists to be confident of the impact and hierarchy of these interventions. Although GOTV studies of this kind cannot adjudicate authoritatively on theories of mobilization, the difference in impact between the types of intervention, in particular the greater success of personalized messages, implies that it is the personal and face-to-face basis of influence that has an effect, rather than the types of message received and the simple provision of information.

So far most of this kind of research has been carried out in the United States, which means that, even with its variety of groups and locations, the range of variation in the institutional frameworks and social conditions is limited to the one-country case.

In multi-party democracies, several parties usually have to join together in coalition to form government. Many aspects of that process have been fairly fully investigated, others less so. Among the latter is the timing of the formation and announcement of coalitions.

While the dominant popular image may be one of parties meeting together after the election to hammer out a coalition agreement, pre-election coalitions of one sort or another are actually quite common. In almost half of the elections in OECD (Organization for Economic Co-operation and Development) countries since the Second World War, at least one pair of parties had pre-announced their intention to join together in government. A quarter of governments formed were based wholly (and another quarter in part) on pre-election agreements.

To date, such studies as there have been of pre-election coalitions have concentrated primarily on system-level explanations – features of the electoral system (majoritarian or proportional, and so on) that make such arrangements more or less likely.3 Here we shall instead look more at the agent-level logic of ‘early’ (pre-election) versus ‘late’ (post-election) coalition formation, from the point of view of voters and parties.

hypotheses concerning coalition timing

In the tradition of Downs and Riker and their coalition-theorist progeny, we shall assume that voters are interested primarily in getting policies adopted which are close to their ‘ideal points’ in policy space, and that parties are interested primarily in winning office to implement policies as close as possible to their ‘ideal points’ in policy space. That leads parties to strive for ‘minimal connected winning coalitions’: ‘connected’ in the sense that they link parties adjacent in policy space; ‘minimal’ in the sense that they involve the party's sharing power with the fewest parties backed by fewest voters that it can and still win.