Effectively maintained inequality in skill acquisition: Uncovering the heterogeneous effect of adult education on cognitive skills

Abstract Evidence shows socio‐economically advantaged people are more likely than the disadvantaged to obtain higher skills. While adult education and training (AET) may potentially solve this skill inequality, its effect is empirically elusive. Using data from the OECD Survey of Adult Skills (PIAAC) first cycle (2011–2012, N = 6397) and second cycle (2022–2023, N = 3654) for Britain, we leverage propensity score matching and unconditional quantile regression to examine relationships among parental status, AET and cognitive skills. The results indicate that (1) AET is positively linked to adult cognitive skills; (2) on average, the association between AET and cognitive skills is stronger among disadvantaged individuals than the advantaged; but (3) the AET effect on top‐level cognitive skills is larger among advantaged individuals. These results suggest that while AET may mitigate origin‐based skill inequality by fostering basic cognitive skills among the disadvantaged, their advantaged counterparts rather harness AET to obtain high‐level skills, which are particularly favoured in the contemporary labour market. Extending social theories, one may call this structure ‘effectively maintained inequality in skill acquisition’, that is, the overall skill inequality seems weakening through the second chance effect of AET, but the unequal distribution of most valuable skill segments rather intensifies. Methodologically, these findings underscore the importance of examining effect heterogeneity of certain interventions/treatments like AET across both social backgrounds and outcomes lest we misunderstand the equalising or stratifying nature of educational opportunities. Considering that education and socio‐economic systems arguably influence these stratification processes, we call for further comparative and longitudinal studies on unequal skill formation mechanisms.