Low hourly wages in middle‐age are associated with faster memory decline in older age: Evidence from the health and retirement study

Background Little research has investigated the long‐term relationship between low wages and memory decline, despite the growing share of low‐wage workers in the US labor market. We examined whether cumulative exposure to low wages over 12 years in midlife is associated with memory decline in later life. Method We used 1992‐2016 data from the Health and Retirement Study, a biennial longitudinal survey of nationally representative samples of Americans aged 50+. We analyzed data from 3,803 individuals born 1936‐1941 using confounder‐adjusted linear mixed‐effects models. Low‐wage was defined as hourly wage lower than two‐thirds of the federal median wage for the corresponding year. Low‐wage exposure history was categorized into ‘never’, ‘intermittent’, and ‘sustained’ based on wages earned from 1992 to 2004. Memory function was measured at each visit from 2004 to 2016 by a memory composite score; on average, participants completed 4.8 memory assessments from 2004‐2016. Estimates were obtained in the total sample and within strata of sex (N males = 1,913, N females = 1,890). Result At the beginning of cognitive follow‐up (2004) our sample was on average 65 years old with a mean memory score of 1.15 standard units. The confounder‐adjusted annual rate of memory decline among workers who never earned low wages was ‐0.12 standard units, 95% CI: [‐0.14, ‐0.10]. Compared with this, memory decline among workers with sustained earning of low midlife wages was significantly faster (β time*sustained :‐0.012, 95% CI: [‐0.02, ‐0.01]), corresponding to an annual rate of ‐0.13 standard units for this group. Put into terms of “excess cognitive aging”, the cognitive aging experienced by workers with sustained exposure to low midlife wages over a 10‐year period is what workers never earning low‐wages would experience in 11 years. Similar associations were found among males and females. No significant association between intermittent earning of low wages and memory decline was observed. Conclusion Sustained earning of low wages in midlife was significantly associated with a downward trajectory of memory performance in older age. Enhancing social policies to protect low‐wage workers (e.g., increasing minimum wage) may be especially beneficial for the cognitive health of individuals with sustained low‐wage employment in midlife.