Occupational sex segregation is one of the most important factors to consider, typically accounting for 10-30 percent of the wage gap (England, 1999). Women and men for the most part do not work in the same occupations or industries (Reskin & Roos, 1990). One index of the sex distribution across occupations is the Duncan Index, calculated from the differences in percentages of women and of men who work in an array of occupations. In 1997 this index showed that over half of employed women (approximately 54 percent) would have had to change occupations to be distributed across detailed occupational categories in the same pattern as men (Jacobs, 1999).” (Hays-Thomas)
Hays-Thomas, R. (2006). Pay equity, a Sloan Work and Family Encyclopedia entry. Retrieved May 10, 1007, from the Sloan Work and Family Research Network website: http://wfnetwork.bc.edu/encyclopedia_entry.php?id=3829&area=academics.