LAUSR

try data and anecdotal evidence. Focusing mostly on parliamentary democracies, the volume rightfully acknowledges the pivotal role of political parties in the internal organization of legislatures. Building on that assumption, the authors offer a parsimonious, formal delegation model, including political parties and backbenchers as two rational actors aiming at maximizing utility derived from speeches in the plenary. The puzzle is both interesting and straightforward: who gains access to the floor to speak on behalf of the party leadership? The model assumes that, as the core organizing unit of work in legislatures, parties have the capacity to select the legislators who will benefit from floor time, an inherently scarce good. Their central argument is that parties need to maintain unity by sending credible signals to voters. Dissent hinders partisan reputation, particularly when a preference outlier legislator takes the stand and produces a speech that is completely at odds with the preferences of the party leadership on that subject. Consequently, parties select legislators who are closer to the ideal point of the leadership. Those who are farther away from the leadership in the policy issue will deliberately be prevented access to the floor by their own party. The authors emphasize that the electoral system and candidate selection mechanisms in political parties are the core explanatory variables to explain variation. In electoral systems in which legislators have incentives to cultivate a personal vote, political parties will have fewer incentives to keep tabs on their members. In this case, legislators will use speeches to signal their individual positions for electoral purposes. Their illustration of the British system highlights how legislators make strategic use of speeches. In this setting, legislators avoid electoral punishment in their constituency by showing public dissent from the party leadership in the plenary in controversial and electorally important matters. Conversely, Proksch and Slapin argue that electoral systems with closed-list proportional representation give different incentives to parties and legislators. The former need to prevent the latter from shirking the party line to maintain the value of the electoral label. The latter need to conform to the party line if they do not want to risk being reselected in the next elections. Their second argument relates to the internal mechanisms of candidate selection. The authors argue that the degree of centralization in candidate selection matters to determine the leeway that legislators have to toe the party line. Ultimately, the implications of these two arguments revolve around parties and legislators adopting rational behaviour in the face of institutional constraints. In institutional settings in which candidate nomination is more decentralized and the electoral system is more personalized, legislators use speeches for their own benefit, expressing their own positions more clearly. Overall, the party leadership has less to lose from potential cohesiveness problems. In those institutional constellations where parties have more internal control over candidate selection and have less personalized electoral systems, legislators need to work towards the maintenance of a credible party label, as this constitutes an important public good. Proksch and Slapin’s work is an outstanding contribution for the comparative study of legislatures, particularly for its travelling capacity and adaptability to different institutional constellations. Their conception of speeches as a game between the leadership and backbenchers is a relevant alternative to traditional measures of party unity, which have been thoroughly explored by political science. Recent developments in computer linguistics over the course of the past decade, as well as the availability of online data, will make the study of speeches increasingly interesting for legislative scholars. Hopefully, this seminal theoretical guide will foster scholarly exploration of the ever increasingly available data.