Previous studies have examined relationships between skills and economic distributions within and across countries to mixed results that relate to both variation in empirical methods and to limited availabilities of consistent skill data separate from education histories. Using multifaceted and internationally comparable skill data from the newly-released Programme for the International Assessment of Adult Competencies (PIAAC), this study adds to the existing literature by examining how literacy, numeracy, and problem-solving skills of adults relate to wage inequality in an international context that is characterized by both economic forces of demand and supply and by institutions. Econometric decomposition, aimed at quantifying contributions of observable and unobservable factors to inequality, is conducted aggregately over all adults and separately by the specific demographic attribute of gender given gender's identified importance in previous literature on earnings inequality. Substantial inequality is documented across countries, skill measures, and gender, thus reinforcing previous findings that skill, even by the broader definition used here, is only a partial explanation for vast differences in economic inequality across countries. The paper concludes with a discussion of relationships to institutional differences within and across countries and of additional ongoing data needs to further understandings of inequality dynamics within and across nations.