Here is a talk by the economist Tim Harford. The title of the talk is "Problem Solving in a Complex World" and was given at a June 11, 2011 meeting of the Royal Society of the Arts (see Wikipedia).
Here is the video:
So how do you successfully solve complex problems? His answer: through evolving a good solution, i.e. through trial and error. But, as he points out, people don't like failure. But it is essential if you are going to solve complex problems.
He is currently touring to promote his new book Adapt: Why Success Always Starts with Failure.