"In the 1990s, economists began producing a string of studies documenting rising income inequality in the United States. ... The debate took on greater specificity with the release of a report in October 2011 by the nonpartisan Congressional Budget Office confirming that income inequality had grown in the United States. According to the report, the top 1 percent of earners more than doubled their share of the nation’s income over the previous three decades." (Quoted from article)