Esiste un sistema elettorale ottimale? La risposta convenzionale è negativa. Ogni sistema elettorale ha pregi e difetti. La scelta del sistema dipende da numerosi fattori, e in primo luogo dagli obiettivi che si vogliono conseguire. Non esiste quindi un sistema intrinsecamente superiore agli altri. Questa risposta vale se la scelta è tra sistemi proporzionali e sistemi maggioritari/uninominali. Non vale però se dobbiamo scegliere all'interno della categoria dei sistemi maggioritari/uninominali.

The starting point of this paper is the outcome of the recent Italian elections of March 27-28, the first to be held in Italy with a mixed electoral system, in part plurality and in part PR. Moving from the observation that a significant number of candidates have been elected with vote percentages well below the majority threshold, the author argues whether the plurality system is the best system for choosing majority candidates, defined in terms of the Condorcet criterion. The search for an alternative leads the author to analyze the merits and demerits of approval voting (AV). The conclusion is that this innovative electoral system has several advantages (particularly vis a vis the plurality system), but it has also one serious limit due to the condition that individual preferences have to be «dichotomous» for the system to perform best. The author argues that, if this condition is met, then AV really is equivalent to the second round of a double ballott majority system with runoff, where the choice is between two sets of candidates, the good and the bad, instead of two candidates. It is suggested that the «ideal» system could be a double ballot one where the rule for the first ballott be absolute majority and the rule for the second be approval voting.