Clooney's Section Eight rely on one hit in every five films
When it comes to getting films made, big-name stars are doing it for themselves.
Ed Harris and Salma Hayek both produced their own dream projects, with Pollock and Frida respectively, which both went on to win Oscars.
George Clooney has gone one stage further, as the most prolific of the stars with "actor power".
Within two months he has released three films he produced himself, Solaris, Confessions Of A Dangerous Mind, and Welcome To Collinwood.
"I love the ability to sit in an office at Warner Brothers, and just by virtue of the fact that I say, 'This is something I want to do', they make it," Clooney told the BBC.
Clooney's production company, Section Eight, was set up jointly with director Steven Soderbergh, and has already produced hits such as Out Of Sight and Ocean's Eleven.
Clooney said that after playing the lead role in 1997's critically panned Batman And Robin - complaints that the film was an over-comercialised mess were commonplace - he had been determined to star in films he believe in.
You have a window of opportunity where you get to call the shots, and at the end of the day say, 'this was my stamp on this'
"After Batman And Robin was when I realised that if I was going to be the guy that was going to greenlight a film and get it made, I had a responsibility not just to getting the role, but to getting the proper films made," he said.
"You have to understand that no-one is encouraging any actor to do what we're doing," he said.
"No agents, no lawyers, no-one - because we're not making money."
The latest project, Welcome To Collinwood, is one example.
"This is a script that has been held up as the best unproduced script ever," Clooney said.
"The film had been basically put in a trash bin, so I picked it up and said, "look, I think I can get the film made"."
Indeed, after Clooney - reluctantly - agreed to star in the film, he agreed to take the absolute minimum permitted by the actors' union in order not to push the budget too high.
Clooney could normally expect $15-20m for a role in a major Hollywood production.
Confessions Of A Dangerous Mind received great reviews - but little box office
"The gamble is of course that those films may very well not do well," Clooney added.
"Jimmy Stewart took a percentage and Bette Davis took a percentage, and those were people who were smart about getting films made.
"You get to a point where you go, 'well I have money.'
"You have a window of opportunity where you get to call the shots, and at the end of the day say, 'this was my stamp on this'.
"I don't think that window is open for a very long period of time."
But the huge increase of stars acting as producers is not solely down to philanthropy - there is money to be made too.
Increasingly, actor's names are seen on the producers' credits of box office smashes - Demi Moore has had a hand in the Austin Powers trilogy, Robert De Niro funded About A Boy, while Tom Cruise put up the money for his ex-wife Nicole Kidman to star in The Others.
But these projects have not starred the actors themselves.
Meanwhile, Section Eight relies on one success in every five films it makes to keep going.