Boing Boing tells us that movie stars don’t sell movies.

Looking across a sample of more than 2,000 movies exhibited between 1985 and 1996, they found that only seven actors and actresses — Tom Hanks, Michelle Pfeiffer, Sandra Bullock, Jodie Foster, Jim Carrey, Barbra Streisand and Robin Williams — had a positive impact on the box office, mostly in the first few weeks of a film’s release.

Robin Williams? Can’t say that I understand why he would help ticket sales. Interesting research though… wonder if any smart studios will start to understand this at a deeper level.

Even more interesting are their research methods:

Anita Elberse, an associate professor at the Harvard Business School, tried to measure the average effect of a star by analyzing casting announcements on the price of stocks on the Hollywood Exchange, a simulated market where hundreds of thousands of users trade stocks in individual movies based on their expected box-office revenue. Prices on this exchange have been found to be fairly good predictors of a film’s box-office success.

Ms. Elberse found, for instance, that the announcement in 2002 that Mr. Cruise had dropped out of “Cold Mountain” — he had been expected to play the lead — reduced the movie’s expected gross by $10 million. The announcement that Mr. Cruise was in talks to play a leading role in “The Last Samurai” lifted the movie’s expected gross by $28 million.