Mixed findings characterize the literature on skills and economic distributions within and across countries. The Programme for the International Assessment of Adult Competencies (PIAAC) offers new, internationally comparable data on literacy, numeracy, and digital problem-solving skills that can be combined with wage information. This paper presents statistical analyses, aimed at quantifying the contributions of observable and unobservable contributors to earnings inequality. Substantial inequality is documented across countries and skill measures, thus reinforcing previous findings that skill, even by the broader definition used here, is only a partial explanation for differences in economic inequality across countries. The paper concludes with future research possibilities that can further understandings of inequality dynamics within and across nations. [The original version of this paper was commissioned by American Institutes for Research (AIR), funded through a contract with the National Center for Education Statistics (NCES).]