Once women start doing a job, “It just doesn’t look like it’s as important to the bottom line or requires as much skill,” said Paula England, a sociology professor at New York University. “Gender bias sneaks into those decisions.”
She is a co-author of one of the most comprehensive studies of the phenomenon, using United States census data from 1950 to 2000, when the share of women increased in many jobs. The study, which she conducted with Asaf Levanon, of the University of Haifa in Israel, and Paul Allison of the University of Pennsylvania, found that when women moved into occupations in large numbers, those jobs began paying less even after controlling for education, work experience, skills, race and geography.
And there was substantial evidence that employers placed a lower value on work done by women. “It’s not that women are always picking lesser things in terms of skill and importance,” Ms. England said. “It’s just that the employers are deciding to pay it less.”
A striking example is to be found in the field of recreation — working in parks or leading camps — which went from predominantly male to female from 1950 to 2000. Median hourly wages in this field declined 57 percentage points, accounting for the change in the value of the dollar, according to a complex formula used by Professor Levanon. The job of ticket agent also went from mainly male to female during this period, and wages dropped 43 percentage points.
The same thing happened when women in large numbers became designers (wages fell 34 percentage points), housekeepers (wages fell 21 percentage points) and biologists (wages fell 18 percentage points).
