Pursuing educational qualifications later in life is an increasingly common phenomenon within OECD countries since technological change and automation continues to drive the evolution of skills needed in many professions. We focus on the causal impacts to economic returns of degrees completed later in life, where motivations and capabilities to acquire additional education may be distinct from education in early years. We find that completing an additional degree leads to more than \$3000 (AUD, 2019) extra income per year compared to those who do not complete additional study. For outcomes, treatment and controls we use the extremely rich and nationally representative longitudinal data from the Household Income and Labour Dynamics Australia survey (HILDA). To take full advantage of the complexity and richness of this data we use a Machine Learning (ML) based methodology for causal effect estimation. We are also able to use ML to discover sources of heterogeneity in the effects of gaining additional qualifications. For example, those younger than 45 years of age when obtaining additional qualifications tend to reap more benefits (as much as \$50 per week more) than others.

翻译：在经合组织（OECD）国家中，由于技术变革和自动化持续推动许多职业所需技能的演变，在人生后期追求教育资格证书已成为日益普遍的现象。本研究聚焦于人生后期完成学位对经济回报的因果效应，此阶段获取额外教育的动机与能力可能与早期教育存在显著差异。研究发现，与未完成额外学习者相比，完成额外学位者每年平均增加逾3000澳元（2019年）收入。我们利用澳大利亚家庭、收入与劳动动态调查（HILDA）中极为丰富且具有全国代表性的纵向数据，对结果、处理组和对照组进行分析。为充分发挥该数据的复杂性与丰富性，我们采用基于机器学习（ML）的因果效应估计方法。此外，机器学习还使我们能够揭示获得额外资格证书效应的异质性来源，例如，在45岁以下获得额外资格证书者往往比其他群体获得更多收益（每周高达50澳元）。