On March 27,1994, after about forty years of proportional representation, national elections to both chambers of the Italian Parliament took place governed by an electoral system with a strong element of plurality. Since then Italy has held one more general election under the new rules (in April 1996). In the present study, we will be concerned with observing and explaining some of the effects of the new rules on the voting behavior of the Italian electorate. Our analysis will focus on the most recent election to the Chamber of Deputies (the lower house).
The rules for the Chamber of Deputies are as follows: approximately three-quarters are now elected on a plurality basis, while the remaining quarter is elected proportionally and essentially on a regional basis. This is operationalized by allowing voters to express two simultaneous votes: one for the single-member college candidate (a Plurality [PL] ballot) and the other for the party for the proportional allocation of seats (a Proportional Representation [PR] ballot). Since each voter has two simultaneous votes available, he or she can express a double preference for a party, by voting for it in the PR ballot and for that party's candidate in the PL ballot. Alternatively, the voter can express split preferences by voting for a party in the PR ballot, but not for that party's candidate in the PL ballot. This phenomenon, that can be described as a “switching-voter phenomenon” (Navarra, forthcoming), can significantly influence the overall results of the elections and, consequently, the formation of the government.