Bus and Train Operators: Men actually work nearly 50% more overtime hours than women, who are less likely than men to game the scheduling system by trading off work hours at regular wages for overtime hours at premium wages

Bolotnyy V, Emanuel N. Why Do Women Earn Less Than Men? Evidence from Bus and Train Operators (Job Market Paper). Working Paper. https://scholar.harvard.edu/bolotnyy/publications/why-do-women-earn-less-men-evidence-bus-and-train-operators-job-market-paper > final version Why Do Women Earn Less Than Men? Evidence from Bus and Train Operators. Valentin Bolotnyy and Natalia Emanuel. Journal of Labor Economics, Jul 2021. https://www.journals.uchicago.edu/doi/10.1086/715835

Abstract: Even in a unionized environment, where work tasks are similar, hourly wages are identical, and tenure dictates promotions, female workers earn $0.89 on the male-worker dollar (weekly earnings). We use confidential administrative data on bus and train operators from the Massachusetts Bay Transportation Authority (MBTA) to show that the weekly earnings gap can be explained entirely by the workplace choices that women and men make. Women value time and flexibility more than men. Women take more unpaid time off using the Family Medical Leave Act (FMLA) and work fewer overtime hours than men. Men and women plan to work similar overtime hours when they are scheduled three months in advance, but men actually work nearly 50% more overtime hours than women. Women with dependents value time away from work more than do men with dependents. When selecting work schedules, women try to avoid weekend, holiday, and split shifts more than men. To avoid unfavorable work times, women prioritize their schedules over route safety and select routes with a higher probability of accidents. Women are less likely than men to game the scheduling system by trading off work hours at regular wages for overtime hours at premium wages. Conditional on seniority, which dictates choice sets, the weekly earnings gap can be explained entirely by differences in operator choices of hours, schedules, and routes.

From the final version: We show that a gender earnings gap can exist even in an environment where work tasks are similar, wages are identical, and tenure dictates promotions. The 11 percent earnings gap in our setting arises from female operators taking fewer overtime hours and more unpaid time off than do male operators. Consequently, we observe that gender neutral policies can have differential effects on the two sexes.

We find that female operators value time, as well as schedule controllability, conventionality, and predictability more than male operators. Male and female operators choose to work similar hours of overtime when they are scheduled months in advance, but male operators work nearly twice as many overtime hours when they are scheduled on short notice. Moreover, male operators game the overtime system more than female operators: when faced with an undesirable schedule, male operators take unpaid time off, but also work more overtime during the rest of the week, resulting in an increase over base income.