"The Great Compression ended in the 1970s. Wages stagnated, inflation raged, and by the decade's end, income inequality had started to rise. Income inequality grew through the 1980s, slackened briefly at the end of the 1990s, and then resumed with a vengeance in the aughts. In his 2007 book The Conscience of a Liberal, the Nobel laureate, Princeton economist and New York Times columnist Paul Krugman labeled the post-1979 epoch the "Great Divergence."

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