We focus on human capital measured by skills and analyse its relationship with R&D investments and productivity across 12 OECD economies and 17 industries. We compute a measure of sectoral human capital defined as the average cognitive skills of the workforce in each country-sector combination. The variation in labour productivity that can be explained by human capital is remarkably large when measured by the sectoral skills, whereas it appears statistically insignificant when measured by the sectoral school attainment. This suggests that using measures of sectoral cognitive skills can represent a major step forward in any future sectoral growth accounting exercise.