Candidacy rules and party unity: The impact of multiple candidacies on legislative voting behaviour in Italy

A common approach among scholars is depicting electoral democracy as a two-round competition for offices, starting with elections and continuing with the allocation of legislative offices among legislators. But what happens when the allocation of seats does not end at Round 1 (elections), but continues as a first stage of Round 2? This may occur when candidacy rules allow candidates to be nominated and elected in more than one district. Multiple candidacies create a pool of vacant parliamentary seats, whose allocation depends mostly on party leaders’ choices. Multi-candidacies increase therefore the centralization of candidate selection process, granting leaders greater post-election influence and decreasing the incentives to vote against party line for those MPs whose parliamentary office depends mostly on the leaders’ will. Data on legislators’ voting behaviour in the Italian Chamber of Deputies (2006–2011) support this notion.