Lifelong learning and adult education are central to adapt to ageing societies, globalization, and automatization. At the same time, causal analyses are scarce in the realm of adult education, mainly because of the voluntary nature of participation and a paucity of high-quality data. After a short motivation and an overview of each chapter in the first chapter, the four essays of this dissertation contribute to understanding institutional, pecuniary, and non-pecuniary aspects of nonformal adult education in Germany.Chapter 2 analyzes whether potential beneficiaries of an early retirement program in Germany voluntarily engage in nonformal adult education. We find that adult education activities increase substantially more after the reform in relatively old counties, i.e., counties with a higher share of older men, compared to relatively young counties, i.e., counties with a higher share of younger men. This increase in participation is observed almost exclusively in cognitively demanding courses, mostly work-related courses. Our results support the notion of an intrinsic willingness of older workers to acquire skills independent of financial incentives.Chapter 3 explores how the most important provider of language courses in Germany, adult education centers (VHS), adapted their course supply of "German as a foreign language" (Deutsch als Fremdsprache, DAF) courses to the refugee wave of 2015/2016. Our results show that VHS reacted quickly and strongly to the refugee influx by massively increasing the number of DAF courses. However, this remarkable expansion came at the cost of offering relatively fewer other courses. In addition, we find that VHS with more resources and more prior experience in organizing DAF courses scaled up their DAF course supply more strongly, which implies path dependency. If equal (learning) opportunities across regions are a societal goal, these inequalities can be seen as problematic.Chapters 4 and 5 make a methodical and a topical contribution to the research on adult education. First, we address empirical challenges in the evaluation of wider benefits from work-related training by transferring a flexible econometric framework from the labor economics literature into the literature that evaluates wider benefits of adult education. We improve upon existing studies by combining the regression-adjusted difference-in-differences (DiD) matching approach with entropy balancing in a multiple event study setting. Second, we apply this framework to identify the effects of work-related training on measures of civic/political, cultural, and social participation (Ch. 4), as well as life satisfaction, worries, and health (Ch. 5). We find that participation in work-related training yields positive non-pecuniary returns in the form of higher civic/political and cultural participation. Those increases do not crowd out social participation. Our results also show that work-related training decreases worries but does not affect satisfaction or (subjective) health. Lastly, Chapter 4 also provides updated estimations on the pecuniary returns to (work-related) adult education.