The ‘paradox of progress’ is an empirical regularity that associates more education with larger income inequality. Two driving and competing factors behind this phenomenon are the convexity of the ‘Mincer equation’ (that links wages and education) and the heterogeneity in the returns to education, as captured by quantile regressions. We propose a joint least-squares and quantile regression statistical framework to derive a decomposition to evaluate the relative contribution of each explanation.