Book excerpt: In his book On Social Closure, Jürgen Mackert seeks to reinvigorate the idea of social closure and bring it back as a basic sociological concept for understanding the strategies and processes powerful groups use to improve their life chances at the expense of the less powerful. To do this, he puts forward a mechanism-based explanatory approach that makes it possible to empirically study social closure through exclusion in the context of neoliberalism; exploitation within global capitalism; and elimination in the ongoing legacy of settler colonialism. Further, he identifies two critical social mechanisms to explain how human beings are denied access to resources, rights, or critical networks and to bring power dynamics into closure analysis.