Market Volatility; Kofi Annan; Nassim Taleb

Financial correspondent Floyd Norris and reporter Katherine Burton explain the current volatility in the stock market due in large part to the housing market. Former U.N. secretary general Kofi Annan sits down with Charlie in Beijing and talks about the environment, the importance of clean water, and life after the U.N. Applied statistician Nassim Taleb introduces his latest book, "The Black Swan: The Impact of the Highly Improbable," in which he asserts that we live in a world we don't really understand.