This article examines how challenger parties enter the political arena and the effect of this entry by looking at the Italian 5 Star Movement (Movimento 5 Stelle – M5S). We explain the M5S's entry strategy in 2013 using the spatial approach to party competition and employing expert survey data collected for each national election between 2008 and 2018. These data allow us to analyse the changing spatial configuration of Italian politics due to the increasing salience of pro/anti-EU and pro/anti-immigration dimensions. We then apply the theoretical notion of the uncovered set (UCS) to trace how the M5S's entry reshaped the overall space of party competition, causing a realignment of existing parties. This work contributes to the ongoing debate on the electoral success of challenger parties and the emerging cleavages and polarization of party systems in Western European countries.

The formation of the ‘yellow-green’ government that took office in Italy after the general election held on 4 March 2018 looked puzzling to many commentators as the two coalition partners – the Five Star Movement and the League – appeared to be quite distant on the left–right continuum. In this article, we argue that despite being widely used in the literature, a unidimensional representation of parties' policy positions on the encompassing left–right scale is inadequate to explain the process of coalition governments' formation. We focus first on coalition outcomes in Italy in the period 2001–18. Our statistical analysis including, among other variables, parties' policy distance on the left–right dimension performs rather well until 2013 but fails to predict the coalition outcome in 2018. To solve the puzzle, we propose a two-dimensional spatial account of the Conte I government formation in which the first dimension coincides with the economic left–right and the second one is related to immigration, the European Union issues and social conservatism. We show that the coalition outcome ceases to be poorly understandable once parties' policy positions are measured along these two dimensions, rather than on the general left–right continuum.

The effects of bicameral legislatures on government formation have attracted scholarly attention since Lijphart’s (1984) seminal contribution. Previous research found support for the ‘veto control hypothesis,’ showing that bicameralism affects coalition governments’ composition and duration. However, the effects of bicameralism on the duration of the bargaining process over government formation have yet to be explored. Our work contributes to this area of research by focusing on the impact of bicameralism on bargaining delays. We show that the duration of the bargaining process over government formation decreases at increasing levels of partisan incongruence of the two chambers, especially in those legislative assemblies in which the upper chamber plays a relevant role in the policy-making process. Such empirical evidence is in contrast with the conventional expectation according to which bicameralism should delay the government formation process, as it introduces an additional element of complexity in the bargaining environment. We test our hypothesis by using a novel data set about the partisan composition of upper and lower chambers in 12 Western and Eastern European democracies over the postwar period.

In this article, we examine the structure of party competition in Italy in the February 2013 elections. We rely on the spatial approach to party competition to analyse the most salient dimensions of the policy space in the Italian context. Our analysis is based on quantitative estimates from expert survey data. These data highlight the salience of the socioeconomic policy dimension and capture the change in the importance of the EU dimension. Finally, this study provides an analysis of potential coalition governments in the aftermath of the 2013 general election that is grounded on the spatial approach to coalition formation.

Mixed-member electoral systems require voters simultaneously to cast ballots in single-member districts (SMD) and multimember, proportional representation (PR) constituencies. It may be that not all parties offer candidates in both electoral contexts, however. In this event would-be voters for some parties may find themselves ‘frustrated’ by the restricted choice menu on offer in the SMD, being effectively forced to split their vote between different parties. Here we explore the different behaviours of frustrated voters in the 1996 mixed-member election to Italy's Chamber of Deputies, characterizing these as being either in some sense non-strategic (concerned above all with the relative policy platforms of candidates) or strategic (concerned above all to influence the eventual composition of government). Using an extended method for ecological inference, we parameterize and estimate rates of different types of ticket-splitting at the district level, and link the degree of what we characterize as strategic voting to the relative policy distance between the respective local representatives of the Italian pre-electoral coalitions.

Tutti gli studiosi concordano nel considerare l'unione degli stati americani creata con la Costituzione del 1787 il primo esempio di federalismo in senso moderno. Qual è la novità storica del federalismo americano? In sintesi, si può affermare che essa consiste in un rafforzamento del potere centrale che si accompagna a un insieme di garanzie costituzionali circa le sfere di autorità o la ripartizione di funzioni tra differenti livelli di governo. La Costituzione di Filadelfia viene inoltre generalmente considerata un esempio di deliberata progettazione istituzionale e i vari saggi che compongono il Federalist – scritti da Hamilton, Jay e Madison allo scopo di illustrare i vantaggi che sarebbero derivati da un'organizzazione federale degli stati indipendenti allora uniti nella confederazione nordamericana –sono considerati la prima articolazione compiuta della teoria federalista. Dall'«invenzione» del sistema americano, che introduce un'innovazione sostanziale nella storia delle istituzioni occidentali, poi ampiamente imitata in numerosi paesi, il federalismo è diventato una delle realtà politiche più importanti e uno dei temi più dibattuti nella letteratura.

Insieme alla ripresa di interesse per il tema dello stato, lo studio delle istituzioni è tornato al centro dell'analisi politologica. È opinione condivisa che il rinnovato interesse per le istituzioni rappresenti una reazione alla rivoluzione comportamentista, la quale a sua volta - con l'enfasi sul comportamento osservabile e sui processi informali di potere e influenza - reagiva all'impostazione legalistica e formalistica degli esordi della disciplina. Ciò che, non senza qualche eccesso polemico, è stato definito uno «slittamento paradigmatico» ha coinvolto una varietà di approcci, accomunati dal riconoscimento dei limiti della behavioral persuasion, e in particolare dei due orientamenti teorici ad essa associati in scienza politica: il pluralismo, con l'accento posto sulla politica come processo e la conseguente messa in ombra degli elementi strutturali, e il funzionalismo, un approccio tendenzialmente più inclusivo ma che in scienza politica si è identificato sostanzialmente con la versione almondiana. Rispetto ai più ambiziosi tentativi teorici del funzionalismo sociologico, essa ha fornito soprattutto uno schema categoriale per l'analisi comparata dei sistemi politici, in cui è attribuito rilievo centrale alle funzioni di input o ai processi che vanno dalla società alla politica.