In various previous attempts to understand the new electoral system that Berlusconi cooked up for this weekend’s Italian election (just click on “Italy” above to see them all in their glory), I have always ended dissatisfied. I could not figure out just what Berlusconi’s “trick” was to divide the left and ensure that he wins even if he loses.
Previous descriptions had indicated that the system was sort of PR, but that the leading bloc of parties would get a guaranteed majority of seats (some sources say 55%, others 60%), and that various thresholds apply for parties in an out of pre-election coalitions. But it was all too confusing.
Well, thanks to Federico Ferrara, it is now much clearer.
For starters, it makes sure that the “winning” coalition – even if it fails to win an actual majority – will take home at least 60% of the seats thanks to a majority premium.
…the threshold… will now keep out of parliament any party affiliated with a coalition that received less than 2% of the vote and any unaffiliated party that receives less than 3%.
As of yesterday, opinion polls indicated that the center-left coalition leads the center-right – at the national level – by about 5%. Assuming for a second this will end up being the margin of “victory,” one would expect that the center-left will receive the 60% of the seats promised by the electoral law and will then divide it up among those parties that have won more than 2% of the vote. Right? Wrong… Say that the left wins 51% of the vote against the right’s 46%. The preliminary distribution of seats to each coalition requires that the coalition be stripped of the votes received by those parties that flunked the 2% test. Assume, as it seems likely, that each of four left parties takes 1.5% of the vote, for a total of 6%. Final score: center-right 46% – center-left 45%. Berlusconi wins a legislature-proof, 60% majority…
I recommend the whole post. In fact, I left out all the juicy parts, in order to focus on the electoral system itself.
NOTE: Federico clarifies further beneath this planting (click on “seeds and scions” below if you are reading this from the main page), and Alex has more here.