Ben Affleck thinks he has more chance of changing the world as an actor than a politician.

The 'State of Play' star - who previously expressed in having a political career - says researching the new movie made him realise he was happier with his current position as he believes he is in a better position to help his favourite causes.

He said: "I like what I'm doing, I like this job. I like directing, writing movies.

"What I discovered from doing 'State of Play' is that you have to be very tough to be a politician. For an actor, one of the things that's most effective for you to do is pick something that you really care about, like a cause or philanthropy or charity and focus on that. I have three things: Operation Gratitude with the troops, Feeding America for people who can't afford food in this country, and trying to work on the humanitarian crisis in Congo.

"I work on those specific things, and try to raise money for them and dedicate my time to them and actually can accomplish something. Whereas politics is a much more tougher, compromised road."