When Does the Personal Vote Matter for Party Loyalty? The Conditional Effects of Candidate-Centred Electoral Systems

Abstract

When do candidate-centred electoral systems produce undisciplined parties? In this paper we examine party discipline under open list proportional representation, a system associated with MPs cultivating personal constituencies. We present a model explaining how legislators' preferences and support among voters mediate political leaders' ability to enforce discipline. We show that disloyalty in candidate-centred systems depends on parties' costs for enforcing discipline, but this conditional on MP preferences. MPs who share the policy preferences of their leaders are loyal even when leaders could not afford to discipline them as high vote getters. We use data on legislative voting in Poland's parliament. Our empirical findings confirm that disloyalty is conditioned on party leaders' enforcement capacity and MP preferences. We find that legislators who contribute more to the party electorally in votes are more disloyal only if their preferences diverge from the leadership.

Keywords: legislative voting, party discipline, political parties, Poland

JEL Classification: D72