Candidate Selection and Party Discipline in Europe: A Comparative Perspective

Abstract

Previous works have argued that candidate selection is an important determinant of party cohesion in parliamentary groups. Candidates selected by party elites tend to form more disciplined parliamentary groups than those selected following more participative processes. This idea has usually been tested by measuring voting blocs (as a proxy of party discipline) and party rules (as indicators of the formal mechanisms of candidate selection). Both indicators have problems since they do not take into account that there are a number of factors leading to party cohesion, leaving the informal mechanisms behind candidate selection. Furthermore, the (scarce) research on this issue involves case studies, which typically ignores the contextual elements behind this relation. In this paper, we use data from a survey of candidates to eight parliamentary democracies to study if and how candidate selection impacts their perception of party loyalty. We demonstrate that exclusive candidate selection promotes more vertical methods of decision making, while participative mechanisms of candidate selection generate less loyal MPs, without eroding the internal cohesion of parliamentary groups. By studying candidate selection and how that relates to party loyalty, we are able to better understand the mechanism at play when party unity is discussed.