Party mergers and vote shifts in Italy

Abstract

Using data from exit polls and two different methods of ecological inference, I demonstrate how Italian voters shifted between 2006 and 2008. Newly merged parties (PdL, PD) were successful in retaining their former voters; parties which looked as if they would be penalized by the electoral system (Sinistra Arcobaleno, UDC) were deserted by voters. The relative success of the Lega Nord and Italia dei Valori results from strong performance in retaining their own voters and marginal transfers of votes from their coalition partners.