"That was when the richest 1 percent accounted for 18 percent of the nation's income. Today, the richest 1 percent account for 24 percent of the nation's income. What caused this to happen? "

http://www.slate.com/articles/news_and_politics/the_great_divergence/features/2010/the_united_states_of_inequality/introducing_the_great_divergence.html