Social capital is a principal concept across the social sciences and has readily entered into mainstream discourse. In short, it is popular. However, this popularity has taken its toll. Social capital suffers from a lack of consensus because of the varied ways it is measured, defined, and deployed by different researchers. It has been put to work in ways that stretch and confuse its conceptual value, blurring the lines between networks, trust, civic engagement, and any type of collaborative action. This clear and concise volume presents the diverse theoretical approaches of scholars from Marx, Coleman, and Bourdieu to Putnam, Fukuyama, and Lin, carefully analyzing their commonalities and differences. Joonmo Son categorizes this wealth of work according to whether its focus is on the necessary preconditions for social capital, its structural basis, or its production. He distinguishes between individual and collective social capital (from shared resources of a personal network to pooled assets of a whole society), and interrogates the practical impact social capital has had in various policy areas (from health to economic development). Social Capital will be of immense value to readers across the social sciences and practitioners in relevant fields seeking to understand this mercurial concept.