Contributor(s): Dr Juliana Bidadanure | Age shapes social institutions, roles, and relationships, as well as how we assign obligations and entitlements within them. Each life-stage also brings its characteristic opportunities and vulnerabilities, which spawn inequalities between young and old. How should we respond to these age-related inequalities? Are they objectionable in the same way gender or racial inequalities are? Or is there something distinctive about age that should mitigate our concern for inequalities between young and old? Juliana Bidadanure addresses these and related questions, presenting the theory of justice between age groups that she develops in her book Justice Across Ages: Treating Young and old as Equals. The book advances ethical principles to guide a fair distribution of goods like jobs, healthcare, income, and political power among persons at different stages of their life. If we are ever to live in a society where people are treated as equals, she argues, we must pay attention to how age membership can alter our social standing, and we must regard with suspicion commonplace forms of age-based social hierarchy.