Second, the effects of socio-economic status on racial/ethnic differences in substance use remain inadequately understood, and some data suggest that racial/ethnic differences in age-related variation could be fully accounted for by socio-economic indicators (Watt, 2008). The extent to which racial/ethnic differences persist despite mean differences in socio-economic status, versus other cultural or social group differences (Zapolski et al., 2014), is important for inferring conclusions from the data on racial and ethnic differences across the lifecourse. For alcohol, available evidence indicates that while income is positively associated with use in general (Keyes & Hasin, 2008), among those in poverty, Black men have higher rates of heavy drinking compared with Whites. (Ford et al., 2007; Gilman et al., 2008; Jones-Webb, 1998; Jones-Webb et al., 1997). Examining these relations across other substances with rigorous control for socio-economic factors is critical.
