A new Russell Sage Foundation book, Unequal Time, has gained significant press coverage over the past few weeks, including profiles in The Nation and Slate, and op-eds by authors Dan Clawson and Naomi Gerstel in The Guardian and The American Prospect. In their book, Clawson and Gerstel illustrate how social inequalities permeate the workplace and exacerbate differences between men and women, the privileged and disadvantaged. They investigate the connected schedules of four health sector occupations: professional doctors and nurses, and working-class EMTs and nursing assistants. Though these workers all experience schedule uncertainty, they do so in distinct ways that vary by gender and class.

In a Q&A with NBC News, Clawson noted, “The thing about health care is that there has to be someone on duty all the time. You can’t have a nurse walk off and have the patients not covered for an hour. That’s uncontroversial, but the way that plays out is unequal by gender and class, and it’s absolutely unsustainable for the lives of low wage workers and women.”

Doctors, who are largely male, have significant control over their schedules, though they often claim otherwise, and tend to work long hours, earning respect from their peers for doing so. By contrast, nursing assistants, primarily female and working-class, work demanding hours and face penalties for taking time off, no matter how valid the reasons. As Jessica Grose put it in her Slate review of Unequal Time, “At the bottom of the totem pole in every respect are the Certified Nursing Assistants.”

Colorlines also recently profiled Unequal Time, and asked the authors how race fit into the picture. Clawson and Gerstel confirmed that the Certified Nursing Assistants (CNA) in their study were 58% non-white, while the other three professions were all less than 13% non-white. In other words, the lowest-paid group in the study was also the one that contained the greatest percentage of non-whites. Gerstel further noted, “It’s the CNAs, the women of color, who have the least amount of control over [scheduling] unpredictability.”

While the work-family literature mostly examines the hours people work, Clawson and Gerstel examine the process through which schedules are set, negotiated, and contested to reveal how time in the workplace is both collective and highly unequal.

Click here to read more about Unequal Time or purchase a copy of the book.