Exploring how discretionary time impacts health
Laura Chen, PhD ’27, is looking at whether having more control over how we spend our time is linked to better health.
Time may be money, but is time health? That’s what doctoral candidate Laura Chen is trying to find out. Based in the Department of Social and Behavioral Sciences at Harvard T.H. Chan School of Public Health, she’s working towards a PhD in the Population Health Sciences program (awarded through the Harvard Kenneth C. Griffin Graduate School of Arts and Sciences). She recently spoke about her dissertation research—which is supported by a predoctoral fellowship award from the American Heart Association—and the study she published last month in The Gerontologist which looked at the health impacts of “job lock.” This is defined as having to stay in a job for income or health insurance, despite the desire to retire.
Q: What did you find in your study on job lock?
A: In a cohort of around 5,000 older U.S. workers, more than three-quarters reported experiencing job lock. Compared to those not experiencing job lock, these individuals had significantly higher odds of poor mental and self-reported health over six years of follow-up even after accounting for key confounders. This group was also younger, more likely to be female, more likely to identify as Hispanic, non-Hispanic Black, or non-Hispanic other, and had lower household income and assets.
I think the key takeaway is that when we live in an economic system that ties people’s basic livelihoods and security to their ability to work, that’s ultimately going to be harmful for well-being. The system is also creating a lot of inequities in who is forced into job lock later in life versus who isn’t.
Q: Your paper mentions that workers’ feelings about lack of autonomy and control may play a role in the link between job lock and worse health outcomes, which ties into your dissertation research on discretionary time and its impact on health. How did you get interested in time as a health resource?
A: I came into my PhD program really interested in how social factors create and reinforce health inequities, and the particular role of unequal exposure to chronic stressors. As I learned about studies of how role overload and conflicts between work and family responsibilities are harmful for health, I got curious about whether we have better ways to study the demands and constraints people face in daily life and how they affect population well-being.
Research in social epidemiology looking at these questions often compares broad groups of people—for example, single working parents versus married working parents. But I was curious about ways to get more specific about the hours and rhythms of people’s daily lives, because that feels like something that’s more intervenable. For my dissertation, I found some interesting work in the feminist economics and sociology literatures that more explicitly measures things like unpaid domestic work time and discretionary time as important household resources, but not much from public health.
We all need time to sleep, exercise, get to the doctor, and be with loved ones. But time as a resource—and our access to it and its flexibility—is all socially patterned and structured by different factors in a way that public health research doesn’t always account for.
Q: What questions are you looking at for your dissertation?
A: I’m looking at discretionary time as a health resource in three different ways: My first study is on how daily leisure time availability affects levels of the hormone cortisol. We know that one way daily stress becomes embodied is through cortisol dysregulation. Over time, this causes inflammation and elevated risks for certain health conditions.
I’m using data from the Midlife in the United States study [a longitudinal research project looking at mental and physical health in older adults] on participants’ daily activities and cortisol levels. Participants reported the time they spent across different activities for several days and provided several saliva samples each day to track their cortisol levels. I’m seeing if there are physiological differences on days when participants had more or less leisure time.
My second study uses a dataset from a nationally representative group of households that includes information on participants’ weekly hours of paid work, childcare, and housework, in addition to demographic and health information including income and new diagnoses of cardiovascular disease. I’ll be analyzing whether being both chronically time-poor and income-poor is worse for health compared to time- or income-poverty alone.
The third study looks at the short-term effects of the Earned Income Tax Credit on people’s health behaviors, using the American Time Use Survey, a big nationally representative survey that’s been running continuously since 2003. Each respondent provides detailed information on what they were up to for the past 24 hours, essentially down to the minute. I’m comparing people who were surveyed around the time the credit is disbursed every year, to those surveyed outside of that window, to see how receiving this money might affect the amount of time that people spend in different health-relevant behaviors like exercising, going to the grocery store, sleeping, and socializing.
Q: Do you know yet what you want to do after you graduate?
A: I want to continue in academic research, especially further exploring longitudinal and large-scale time use data to see what it can tell us about class differences and social differences in health.
