Differential relationship between state-level minimum wage and infant mortality risk among US infants born to white and black mothers

Abstract

BackgroundCompared to other Organisation for Economic Co-operation and Development (OECD) nations, US infant mortality rates (IMRs) are particularly high. These differences are partially driven by racial disparities, with non-Hispanic black having IMRs that are twice those of non-Hispanic white. Income inequality (the gap between rich and poor) is associated with infant mortality. One proposed way to decrease income inequality (and possibly to improve birth outcomes) is to increase the minimum wage. We aimed to elucidate the relationship between state-level minimum wage and infant mortality risk using individual-level and state-level data. We also determined whether observed associations were heterogeneous across racial groups.MethodsData were from US Vital Statistics 2010 Cohort Linked Birth and Infant Death records and the 2010 US Bureau of Labor Statistics. We fit multilevel logistic models to test whether state minimum wage was associated with infant mortality. Minimum wage was standardised using the z-transformation and was dichotomised (high vs low) at the 75th percentile. Analyses were stratified by mother's race (non-Hispanic black vs non-Hispanic white).ResultsHigh minimum wage (adjusted OR (AOR)=0.93, 95% CI 0.83 to 1.03) was associated with decreased odds of infant mortality but was not statistically significant. High minimum wage was significantly associated with reduced infant mortality among non-Hispanic black infants (AOR=0.80, 95% CI 0.68 to 0.94) but not among non-Hispanic white infants (AOR=1.04, 95% CI 0.92 to 1.17).ConclusionsIncreasing the minimum wage might be beneficial to infant health, especially among non-Hispanic black infants, and thus might decrease the racial disparity in infant mortality.

State‐Level Social and Economic Policies and Their Association With Perinatal and Infant Outcomes

“…Outcomes varied across the studies but primarily included birthweight and neonatal/postneonatal and infant mortality. One study calculated infant birthweights for gestational age z‐scores, 34 and another study included gestational age and fetal growth in their models 35 …”

“…The other studies we reviewed revealed significant overall improvements with minimum wage increases. For example, Komro and colleagues and Wehby and colleagues showed that on average, every $1 increase in the minimum wage led to reductions of approximately 1% to 2% in low birthweight births and 4% in postneonatal mortality, and increases of 0.1% in birthweight and fetal growth 35,37 . In addition, Andrea and colleagues found that a more expansive wage policy was associated with a higher birthweight for the smallest infants and a lower birthweight for the largest infants 34 …”

“…One study calculated infant birthweights for gestational age z-scores, 34 and another study included gestational age and fetal growth in their models. 35 All but one study found an overall significant association between minimum wage change and the outcomes. Rosenquist and colleagues found that an increase in minimum wage was associated with a significant reduction in infant mortality, but only among infants with non-Hispanic Black mothers.…”

Structural interventions that affect racial inequities and their impact on population health outcomes: a systematic review

“…Eight quasi-experimental studies (32-37, 39, 40) and the one RCT (38) explored interventions related to nancial policy in the USA. Interventions aligned with macroeconomic policies in the WHO CSDH framework (28), such as the Earned Income Tax Credit (EITC) for low-to-moderate-wage earners (32,34,35,37,39), and/or minimum wage laws (36,40). Other interventions aligned with social protection public policies as a determinant of health, such as Old Age Assistance (33), and the New Jersey Family Development Program (38).…”

“…Rosenquist et al examined infant mortality for Black and White women across States with different minimum wage levels over three decades. They found that the odds of infant mortality decreased for Black women when minimum wage was higher (adjusted OR 0.80, 95% CI 0.68, 0.94), or had seen a larger increase (adjusted OR 0.89, 95% CI 0.82, 0.96)(40). The USA's Old Age Assistance (OAA) program expanded in 1935 under the Social Security Act to provide nancial bene ts to seniors(33).…”