Recently, the debate about electoral reform in Italy has begun to move quite quickly. A number of parties - including the pivotal UDC - seem to favour the German mixed-member system. Rocco Buttiglione, in yesterday's Repubblica, claimed that such an electoral system would leave Italy with four parties - radical left, centre-left, centre, and respectable right.
Buttiglione's comment - and support for the German system in general - demonstrate one of two fallacies of institutional reform commonly seen in Italy.
The fallacy of composition is where one takes two institutional features, which are believed to have certain independent effects, and where one seeks to reach a half-way point between these two effects. Instead, the two institutional features, when put together, interact and cause unforeseen outcomes.
An example of this is the combination of single member districts (SMDs) and a proportional tier in the Italian electoral reform of 1993. Giovanni Sartori criticised the choice as leading to a vogue for 'bastard hybrids'. If the intent was to reduce the effective number of parties (ENP) through introducing SMDs, the reform failed; the ENP increased after 1993.
The fallacy of abstraction is where one takes a particular institutional artefact, which is believed to have a particular effect within a wider context; and replicates it without that wider context.
If Italy adopted the German electoral system because it has historically produced stable and alternating governments, legislators will have succumbed to the fallacy of abstraction. The stability and alternation of German government was due first to the gradual instauration of the electoral system, and also to the cleavage structure. The more complex cleavage structure in Italy - including clerical/anti-clerical and communist/socialist left cleavages - will most likely make any reductive effect of the electoral system much less likely.