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

Abstract

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 confounderadjusted 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 10year 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