Scorporo

Scorporo (, ) is a partially compensatory, mixed-member majoritarian electoral system, sometimes referred to as a negative vote transfer system (NVT) whereby a portion of members are elected in single-member districts (SMDs) and a portion are elected from a list. It may be fully defined as a parallel voting system which excludes a portion (up to 100%) of the SMD winners' votes in electing the proportional tier, to result in a more proportional outcome. The exclusion of a portion of the SMD winners' votes is what makes scorporo fundamentally different from parallel voting and somewhat closer to the additional member system in the UK (a form of mixed-member proportional representation) in theory. However, the design proved particularly susceptible to the decoy list strategy, and as a result by 2001 had devolved into a de facto parallel voting system. The scorporo method is only known to have been used in Italy, but a similar version is in used for the National Assembly of Hungary.

== Implementation == Scorporo was in force for elections to the bicameral Parliament of Italy based on Law 277/1993 from 1993 to 2005. Under this system, members could be elected in two ways: 75% of elected members were elected in single member districts (SMDs) using first-past-the-post voting. 25% of elected members were elected on list basis based on the proportion of the votes received by the party (using the D'Hondt method), with the exclusion of a proportion of any first-placed winner's votes.