Institutional and Organizational Causes of PPG Factionalism: a Comparative Analysis.

Within the literature devoted to the study of political parties, little attention has been directed towards intra-party factions and factionalism, and the roots of such phenomena remain obscure. This paper aims at analyzing some macro and meso level causes of factionalism within the parliamentary party group (PPG) across 15 European democracies, by using the PARTIREP MP Survey dataset. PPG factionalism is operationalized as a propensity to dissent, measured through MPs’ dissenting preferences, attitudes and behaviors. This study adopts a rational choice institutional approach, and argues that these preferences, attitudes and behaviors are affected by institutional and organizational incentives, at both the electoral and nomination stages. Accordingly, this paper builds a series of hypotheses on the impact of electoral system and candidate selection methods on PPG factionalism, and also controls for variables such as state structure (multilevel or unitary), PPG position (in government or in opposition) and PPG composition (whether the PPG is a gathering of various extra-parliamentary political associations, or rather corresponds to the party in public office). At the empirical level, the paper tests these hypotheses through multiple linear regression techniques. Despite its theoretical, empirical and methodological limits described in the conclusion, this paper brings new evidence regarding institutional and organizational arrangements impact on PPG factionalism.