Automated content analysis is employed to measure the dimensionality of Senate debates on the 2003 Partial-Birth Abortion Ban Act and compare these results with the final vote. The underlying verbal conflict leading up to the final roll-call vote contains two important dimensions: (1) an emotive battle over the abortion procedure itself, and (2) the battle over the constitutionality of the bill. Surprisingly, senators appear not to have voted along the first dimension of the verbal conflict, but rather along the second dimension. The analysis of the deliberations of senators not only enables us to understand the complexity of the arguments that is not captured in the vote, but it also uncovers (and measures empirically) the strategies employed by legislators to shape the relevant lines of conflict, and ultimately, the final content of the bill.

Authoritarian governments may face serious uncertainties when dealing with popular resistance because of the unpredictable consequences of making concessions or repressing opposition. However, a political system with multiple levels of authority can help reduce the uncertainties by granting conditional autonomy to lower-level authorities. Such a power structure prevents excessive repression and unconditional concessions when the priorities of different levels of authority do not match. Under this political arrangement, the central authority can avoid blame when local authorities use repression. The divided power also helps reduce the uncertainties faced by the central authority because it will then have to deal with only a very limited number of instances of resistance. Using the case of China, this article shows that divided state power has allowed the party-state to maintain social stability amid numerous instances of social unrest during the reform era.

This article presents evidence that both micro (individual level) and macro (aggregate level) theories of public opinion overstate the importance of political sophistication for opinion change. It is argued that even the least politically sophisticated segment of society receives messages about the economy and uses this information to update attitudes about political issues. To test this hypothesis, the authors have used General Social Survey data to construct a 31-item measure of policy mood, disaggregated by political sophistication, that spans from 1972 to 2004. They found that all the subgroups generally changed opinion at the same time, in the same direction, and to about the same extent. Furthermore, they show that groups at different sophistication levels change opinions for predominantly the same reasons.

The central question in this study is whether the power of the media agenda over the political agenda has recently increased. The agenda-building dynamics are established using cross-country time-series data on four issues, covering fifteen and eight years respectively of British and Dutch parliamentary debates and newspaper articles. Structural equation models show that the parliamentary agenda is more influenced by the media agenda than the other way around, and that the power balance has shifted even more in favour of the media. It is additionally found that media power is especially associated with issues within the European domain. This study contributes empirically to the 'mediatization' debate in a EU context, which is largely limited to the realm of theoretical speculation.

There is extensive theoretical research that explores the linkages between parties' policy positions, on the one hand, and the characteristics of the political system (i.e. voting rules and the number of parties) on the other, but empirical research on this topic is less developed. Building on earlier work by Jay Dow, this article reports empirical analyses exploring the connections between the average party policy extremism in fifteen party systems (defined as the average party policy distance from the party system centre), and two important system-level variables: the proportionality of the electoral laws used to select representatives to the national legislature, and the number of political parties. Contrary to expectations – but consistent with recent theoretical work by Norman Schofield and his co-authors – no evidence is found that average party policy extremism increases under proportional representation, nor that policy extremism increases in countries that feature large numbers of parties. These findings have important implications for political representation and for understanding parties' election strategies.

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.

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.

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.

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.