Last year, male scientists in the United States earned 20% more on average than did female scientists, according to a report by the US National Science Foundation in Arlington, Virginia. The Survey of Doctorate Recipients looked at salaries across academia, government, industry and the non-profit sector, and found that full-time scientists earn a median of US$100,000, with men at $110,000 and women at $88,000. The disparity is probably because of institutional bias at the earliest career levels, says Janet Bandows Koster, chief executive of the Association for Women in Science in Alexandria, Virginia. She notes that salary differences compound as female scientists advance up the career ladder. Women “are getting a percentage increase based on a smaller amount”, she says.