When all things appear to be equal, why do female workers still make less than their male counterparts?
A study scheduled to be published in the April issue of the Journal of Labor Economics examined the 11% wage gap between female and male transit workers who make the same wages and concluded that overtime plays a key role.
The researchers studied time cards filed from 2011 to 2017 by 3,011 full-time bus and train operators at the Massachusetts Bay Transportation Authority, where about 30% of public transit operators are women.
The researchers found that female operators took home $0.89 for every dollar earned by a male operator, an 11% wage gap that carries over into retirement.
“We demonstrate that even when men and women work at precisely the same job with exactly the same incentives, women earn less,” they write.
Upon inspection, they found male transit operators took 1.3 fewer unpaid hours off work per week 49%), and worked 1.5 more overtime hours than women (83%).
The researchers attribute much of the wage gap to men working more overtime hours, while women leave work or take time off to handle a disproportionate burden of household and childcare duties.
The authors of the paper, Why Do Women Earn Less than Men? Evidence form Bus and Train Operators, are economists Valentin Bolotnyy of Stanford University and Natalia Emanuel of Harvard University.
They urge employers to increase working hour predictability and controllability to narrow the wage gap, while using “shift sharing” and employee task checklists.
The researchers concluded that female operators value time outside work and schedule predictability and controllability more than men.
“The differences are consistent with women handling more household and childcare duties than men, contributing to women’s limited availability for overtime shifts and need to take more unpaid time off,” they said.
The research said their results “are consistent with male operators doing more childcare through their pocketbooks and with female operators doing more childcare through time spent outside work.”
The researchers found the wage gap disparity was exacerbated because male operators were more successful at exploiting a past MBTA policy that allowed them to earn more by “strategically” substituting regular hours for higher-paying overtime hours under the Family and Medical Leave Act.
During the study period, unmarried women with dependents took the largest amount of unpaid time off through FMLA, making them the lowest earners at the MTA.
The researchers said one reason female operators take fewer overtime hours is because the MTA offered the overtime hours are offered on short notice.
They state that “more predictable and controllable schedules have the potential to help female operators work more hours, reduce the earnings gap, and improve employee well-being.”
When overtime hours are scheduled 3 months in advance, the researchers said male operators sign up for only 7% more overtime hours than female operators.
According to Bolotnyy and Emanuel, the wage gap in weekly earnings between men and women generally shrank from 38% in 1979 to 20% in 2004, but has now plateaued at about 18%.
The Journal of Labor Economics is published by the University of Chicago Press.