Male-female income disparity, also referred to as a "gender gap in earnings", in the United States, also known as the "gender wage gap," the "gender earnings gap" and the "gender pay gap", is used by government agencies and economists to refer to statistics gathered by the U.S. Census Bureau, as part of the Current Population Survey, comparing median male wages to median female wages. The gender gap is usually expressed as the ratio of female to male earnings among full-time, year-round (FTYR) workers.
IN 2006 the median income of FTYR male workers was $40,798, compared to $31,223 for FTYR female workers (DeNavas-Walt et al, 2005). 31,223 divided by 40,798 is .765, so the gender earnings gap in 2006 was .765. This is often expressed as a percentage: e.g., "in 2006, women's wages were 76.5% of men's wages," or "in 2006, women earned 23.5% less than men earned."