This paper examines human capital inequality and how it relates to earnings inequality in Portugal using data from Quadros de Pessoal for the period 1986–2017. The objective is threefold: (i) show how the distribution of human capital has evolved over time; (ii) investigate the association between human capital inequality and earnings inequality; and (iii) analyse the role of returns to schooling, together with human capital inequality, in the explanation of earnings inequality. Our findings suggest that human capital inequality, computed based on the distribution of average years of schooling of employees working in the Portuguese private labour market, records a positive trend until 2007 and decreases from this year onwards, suggesting the existence of a Kuznets curve of education relating educational attainment levels and education inequality. Based on the decomposition of a Generalized Entropy index (Theil N) for earnings inequality, we observe that inequality in the distribution of human capital plays an important role in the explanation of earnings inequality, although this role has become less important over the last decade. Using Mincerian earnings regressions to estimate the returns to schooling together with the Blinder-Oaxaca decomposition of real hourly earnings we confirm that there are two important forces associated with the observed decrease in earnings inequality: a reduction in education inequality and compressed returns to schooling, mainly in tertiary education.

本文使用Quadros de Pessoal 的数据研究了葡萄牙的人力资本不平等及其与收入不平等的关系1986-2017 年期间。目标有三个：(i) 展示人力资本的分配如何随时间演变；(ii) 调查人力资本不平等与收入不平等之间的关联；(iii) 分析教育回报以及人力资本不平等在解释收入不平等中的作用。我们的研究结果表明，根据在葡萄牙私营劳动力市场工作的雇员平均受教育年限的分布计算的人力资本不平等在 2007 年之前呈正趋势，并从今年开始下降，表明存在教育的库兹涅茨曲线将教育程度与教育不平等联系起来。基于对收入不平等的广义熵指数 (Theil N) 的分解，我们观察到，人力资本分配的不平等在解释收入不平等方面起着重要作用，尽管这一作用在过去十年中变得不那么重要了。使用 Mincerian 收入回归来估计学校教育的回报以及实际小时收入的 Blinder-Oaxaca 分解，我们确认有两个重要的力量与观察到的收入不平等的减少相关：教育不平等的减少和学校教育的压缩回报，主要是在高等教育中。