Daniela Gutermann

• Since people spend around one third of their day at work, the question of which factors enhance their well-being and their motivation at work is an important one. Moreover, organizations have to face several challenges, such as a quickly changing global economic market, digitalization, and continuous need for innovation (Cascio & Montealegre, 2016; Frese, 2008; Leibold & Voelpel, 2006). Work engagement is a construct that is an asset for both employees and organizations. This dissertation aims to answer the question which factors may foster work engagement within organizations and how this is related to individual and organizational performance across different organizational levels. In order to shed light on these questions, this dissertation investigates how constructive and destructive leadership is related to work engagement and which role leaders’ work engagement itself may play for followers’ tendency to engage in their work. Additionally, since a lot of organizations are interested in the topic of work engagement, a new engagement assessment – the Engagement Index (ENG-I) – is introduced that faces both, scientific and organizational requirements. Finally, the link between individual and organizational work engagement and performance is analyzed by considering causality issues. In sum, this dissertation can show that indeed, leadership is an important lever for work engagement, that the ENG-I shows to be a statistically validated and well accepted measurement of work engagement, and that individual and organizational work engagement leads to individual and organizational performance.