ITALY: Italy has a lower house (camera) and an upper (senato). A coalition must win a majority in both to have a mandate to govern. Every law has to be approved by both houses.
Who can vote?
Italians aged 18 or over can vote for the lower house, while they must be 25 to have a senate vote - about 8 per cent fewer could vote for the latter. In addition, parties and coalitions which run for each chamber can differ, making it difficult to compare results.
Whom did they vote for?
Italians in Italy voted for 618 members for the lower house and for 309 senators. Italians living abroad elected 12 lower house deputies and six senators, giving 630 lower house deputies and 315 senators. In addition, there are seven senators appointed for life so the senate has 322 members.
How are the seats assigned?
Seats are assigned by PR, with the guarantee of an absolute majority for the coalition which emerges ahead. However, the rules governing the two houses differ. In the lower house, seats are determined on a national basis. The coalition that won most votes was guaranteed at least 340 of the lower house's 630 seats (54 per cent) even if, as happened, it won less than 54 per cent of the vote.
In the senate, seats are determined region by region, with the winner in each of 20 regions awarded at least 55 per cent of seats up for grabs in that area. That means the senate's final make-up does not necessarily reflect the split in the national vote.