ROME Italy's election not only shocked the political establishment to the core, it left polling companies with egg on their face after they completely failed to predict the messy outcome and the spectacular resurgence of Silvio Berlusconi.
Opinion polls are banned in the last two weeks before Italian elections and the last public ones on February 8 almost all predicted a clear center-left victory, mostly by around five percentage points.
Private conversations with several pollsters after that date and right up to the election suggested the center-left had hung on to enough of a lead to still clearly win the election, with majorities in both houses of parliament.
The actual result was very different. The center-left of Pier Luigi Bersani won the lower house vote by less than one percentage point, although it benefited from a winner's bonus to give it comfortable control.
However, in the Senate, the rise of populist comedian Beppe Grillo and of Berlusconi, combined with the poor performances by both the center left and centrist Monti left Bersani far short of a majority and threw Italy and international markets into confusion.
The instant polls done by polling companies straight after the election ended also got the result completely wrong, predicting a strong center-left victory and causing a brief market rally before computer projections based on actual votes began showing the opposite result.
Maurizio Pessato, vice president of polling company SWG, said all pollsters had underestimated the shock comeback by Berlusconi, who mounted an extraordinarily effective campaign after overcoming months of indecision in December and entering the race.
BERLUSCONI SURGE MISSED
He told Reuters that although some other polling companies also underestimated the rise of Grillo, whose 5-Star Movement became Italy's biggest single party with about 25 percent of the vote, the real hidden element that created a dangerous stalemate in parliament was the extent of Berlusconi's success.
Another prominent pollster, Renato Mannheimer, said the huge shake-up in politics caused by Grillo's rise, combined with a sharp increase from 20 to 35 percent in those making last-minute decisions on how to vote, had thrown computer models based on previous elections and the methods used to analyze them out of kilter.
"Based on this experience, many (polling) methods must be seriously reassessed," Mannheimer said in Corriere della Sera daily.
Pessato said that Berlusconi's vote had now been underestimated by pollsters in three successive elections dating back to 2006, when the media tycoon had staged a last-minute surge, as he did in this vote.
"The center-right was growing and it wasn't showing in the polls. I spoke to other companies and they said the same thing," Pessato said.
This was particularly important in pollsters' estimates of the Senate race, where Berlusconi won far more regions than expected. Under the peculiarities of Italy's electoral law, winner's bonuses are awarded by region for the Senate.
"We expected the center-left to be able to control the Senate together with Monti but this did not happen," Pessato added.
The major reason for missing the 76-year-old billionaire's late surge was that conservative voters supporting Berlusconi tend to refuse to be interviewed by pollsters, he added.
There is also another factor noted by many pollsters - Berlusconi voters often refuse to admit it because of the scandals surrounding the billionaire media magnate.
"This time there were even more controversies and scandals so probably some of them didn't want to say they voted for him, or refused to accept the interview," Pessato said.
Berlusconi, who has faced at least 30 prosecutions for corruption and other offences in his 20 years at the center of the political stage, is currently on trial charged with having sex with an underage prostitute during "bunga bunga" orgies at his villa.
(Writing by Barry Moody; Editing by Michael Roddy)