Similar to previous research, a new working paper shows that the gender wage gap is driven largely by the amount of hours men and women choose to work. The authors draw on data from the Massachusetts Bay Transportation Authority (MBTA), explaining that the “bus and train operators are all represented by the same union, Carmen’s Local 589, and are all covered by the same bargaining agreement. The agreement specifies that seniority in one’s garage is the sole determinant of one’s work opportunities. Conditional on seniority, men and women face the same choice sets of schedules, routes, vacation days, and overtime hours, among other amenities” (pg. 2).
What do they find?
We show that a gender earnings gap can exist even in a controlled environment where work tasks are similar, wages are identical, and tenure dictates promotions. The gap of $0.89 in our setting, which is 60% of the earnings gap across the United States, can be explained entirely by the fact that, while having the same choice sets in the workplace, women and men make different choices. Women use the Family Medical Leave Act (FMLA) to take more unpaid time off than men and they work fewer overtime hours at 1.5 times the wage rate. At the root of these different choices is the fact that women value time and flexibility more than men. Men and women choose to work similar hours of overtime when it is scheduled a quarter in advance, but men work nearly twice as many overtime hours than women when they are scheduled the day before. Using W-4 filings to ascertain marital status and the presence of dependents, we show that women with dependents – especially single women – value time away from work more than men with dependents.
When selecting their work schedule for the following quarter, women try to avoid inconvenient days, like weekends, and shifts, like split-shifts, more than men. Prioritizing schedule related amenities over route quality-related amenities, women select routes with higher probabilities of assaults and collisions in order to avoid unfavorable schedules. When faced with having to work an unfavorable schedule, like a weekend, holiday, or split shift, women take more unpaid time off. Men also take more unpaid time off in those circumstances, but they more than make up for lost earnings with overtime. While constrained schedules lead to lower earnings for women, they result in higher earnings for men. In an effort to reduce absenteeism and overtime expenditures, the MBTA oversaw two policy changes: one that made it harder to take unpaid time off with FMLA and another that made it harder to be paid at the overtime rate. While the policy changes reduced the gender earnings gap from $0.89 to $0.94 and made it harder for operators to trade off regular hours for overtime, they also decreased women’swell-being by further constraining the work environment (pg. 34-35).