If Berlusconi somehow wins, I would doubt very much that alliance lasts 4 years in power. There will be probably be conflicts with Lega Nord, but almost certainly there will be conflicts when Berlusconi decides he wants the actual premiership and not just a puppet who may or may not exhibit independence.

I would think a system which creates a smaller number of larger parties would be more stable-perhaps true MMP with a single ballot (list seats based on constituency votes), and forbidding pre election alliances to be formed (perhaps banning party mergers after electionsare called to strengthen this). I also think allowing the PM to call for a Senate-only election (for the unexpired term until the next general election) with restrictions (say, only if confidence is lost, and not within one year of the previous Senate election) would substantially help. If the PM lost the new Senate election, he could be required to resign.

I agree with MSS that the scorporo did not “turn the system into MMM”. However, the presence of decoy lists created not only problems of accountability and representativeness but it also generated institutional weakness. In the 2001-2006 legislature the parliament had 12 seats less than usual due to the ‘scorporo’ misunderstanding and misinterpretation. In fact in those decoy lists the biggest parties (and in particular that related to Forza Italia) included a number of candidates shorter than the number of seats they won. So those seats had could not been assigned.

Yes, the introduction of the constructive vote of no confidence may support the government stability and contemporarily make more responsible the smaller parties. The problem of Italian party system is not the presence of an important number of (small) parties, but rather their ‘relevance’ and ‘blackmail’ power.

I think that there is not a ‘right’ electoral system in absolute terms. However, a system that would increase accountability and government stability is needed. Not only plurality could so. Vice versa, a PR system with small-medium districts it will both take in account the need of representativeness of socio-political cleavages still relevant in the country, and push toward a more stable party and government systems.

PS: I do not think the main problem is the parliamentary size (lower house): Germany and France have similar number of deputies and a quite similar population too.

Germany’s politics could be said to be even less two-bloc than that, particularly at the state level. Red-red coalitions (SPD-Linke) have occurred.

After the Saarland election in 2009, the Greens held the balance of power between the CDU-FDP bloc and the Red-red bloc (the existence of this bloc as a potential government may have been helped by the fact that Oskar Lafontaine, a former SPD Minister-President and federal Chairman, was the leader of the Left). Contrary to what may have been expected, the Greens chose to support the CDU-FDP bloc, forming Germany’s first “Jamaica alliance” (black-yellow-green), though from outside cabinet rather than in the government. It collapsed early, in 2012, but it was not because of the Greens defecting, but rather because of internal fighting within the FDP.

The earliness of the election was occasioned by policy disagreements with the outside supporter of the Labour-led minority government, the Greens. They had quite an uneasy partnership, and we could say that the party system at the time was short of being clearly two-bloc in nature. Labour called the election early because PM Helen Clark thought she might be able to win an outright majority. She did not, but was able to bring in a center-right support party, the United Future, and dispatch the Greens to the opposition. The UF is somewhat analogous to the German FDP in that it has supported governments led by either of the big parties, though it is a much less significant political force in its own right.

Also, I would not agree that no party in New Zealand under MMP has come close to a majority. National currently has 59 seats out of 121. In 2008 it had 58 out of 122.

Actually, Italy since the mid-90s, as well as Germany and New Zealand (even post-reform), all have essentially two-bloc systems. However, in Italy, those blocs mask a very fragmented party system in which the component parties of the blocs retain separate identity–and periodically demonstrate their independence.

Interestingly, of the countries just named, Germany really is the least two-bloc. The FDP has at times governed with either of the two major parties, the major parties have governed together, and the Left is not part of either bloc.

It is true that parties could “game” the system by setting up decoy lists, but it is not the same as the practice in various elections in actual MMP jurisdictions (e.g. Lesotho, 2007).

Alternatively, Italy just has unstable party politics. If it were up to me, I would make the Senate elected through single member districts but not have any say in government formation. Whoever can form a coalition in the chamber of deputies can lead the government for as long as that coalition is stable. The Senate would lose no other powers.