“Inequality of both income and wealth has been increasing in the US since the 1970s. As a result, there are many more wealthy Americans—the number of multimillionaires quadrupled between 1983 and 2007. At the same time, the real (inflation-adjusted) wage of American men today is lower than 40 years ago.”

Peter Turchin - “Ages of Discord: A Structural-Demographic Analysis of American History”