Who joins commons initiatives, and why? This paper presents a scoping review of 53 theoretical and empirical studies from 2004 to 2023, focusing on the sociodemographics of commoners and their individual and group motivations for joining. The review reveals that a wide range of people participate in commons initiatives for a variety of complex reasons. Their decision to join may be influenced by normative motives, such as biospheric values and feelings of ethical responsibility. They may be motivated by self-interest, such as positive outcome expectations, or by high self-efficacy beliefs and easy access to the initiative. In terms of group motivations for joining commons, we highlight social identity, collective efficacy beliefs, mutual support and reciprocity, collaborative decision-making, and trust. Applying a broad theoretical and geographical scope in our review enhanced our understanding of people who participate in commons initiatives in the Global North and South.
