Patterns of party switching in the Italian Chamber of Deputies 2008-2011

Abstract

Party switching has been defined as an «umbrella label for any recorded change in party affiliation on the part of a politician holding [...] elective office» (Heller and Mershon 2009, 10). Although party switching is not a widespread phenomenon in legislatures, it has recently become the object of an expanding literature within political science. The literature has emphasized «normative, theoretical and substantial implications» of party switching (Heller and Mershon 2009, 4) insofar as party switching (a) deals with accountability, responsibility and representation, (b) provides new and powerful leverage on party discipline and on the dynamics of party systems, (c) matters because, at least potentially, it alters policy bargaining in the legislature and even government composition. Data show that in the last two decades party switching occurred both in new democracies or weakly institutionalized party systems such as Brazil, Russia, Poland and Ukraine and in established democracies facing institutional changes and electoral realignment such as Italy and Japan1.