Ballot structure, list flexibility and policy representation

There is a growing body of research on the impact of the electoral system ‘ballot structure’ on the behaviour of politicians. We offer a clear, ordinal and rules-based three-way coding (closed, flexible, open) of the electoral systems used in European Parliament elections, taking into account both the ballot type and the intra-party seat-allocation rules. For the notoriously difficult group of flexible list-systems, we show how these operated in the 2004, 2009 and 2014 elections, and introduce an additional behavioural distinction between ‘weakly flexible’ and ‘strongly flexible’ subtypes at the party-list-level. We then illustrate how the type of ballot used in an election can influence individual policy representation by looking at the vote-splits between Members of the European Parliament (MEPs) in the European People’s Party in a vote on tackling homophobia.