Unstable hours, unequal health: Gendered occupational health costs of work-hour volatility in the U.S.

Introduction: Work-hour instability is a key feature of precarious employment, yet its population-level health implications remain insufficiently understood and may be obscured by employment-based selection. Methods: Using the Current Population Survey linked across two four-month observation periods separated by an eight-month unobserved interval, we construct a work-hour volatility index from within-person changes in work hours and estimate gender-stratified multinomial logit models to assess whether volatility predicts subsequent transitions in self-rated health (SRH) and health-related work limitation (HRWL) as an additional outcome. Results: Results show gender-differentiated patterns. Among men, work-hour volatility is associated with a higher likelihood of SRH deterioration while remaining employed. Compared with stable 40-hour weeks across four monthly observations, a volatile pattern of 20-hour weeks in month 1, 60-hour weeks in month 2, 60-hour weeks in month 3, and 20-hour weeks in month 4 was associated with a higher predicted probability of SRH deterioration (38.0% vs. 28.1%). Among women, volatility is not clearly associated with SRH changes; however, under the same contrast, predicted HRWL probability is higher under high volatility than stable hours (5.2% vs. 2.5%). Conclusion: Our findings suggest that work-hour volatility is a meaningful, gendered dimension of occupational health risk, with implications for both health inequality and labor-force attachment. Policies promoting stable working hours should be considered because they may have public health benefits.