Justice Between Coexisting Generations: Birth Cohorts or Age Groups?

ABSTRACT This paper will deal with intergenerational justice, focusing on the relationship between coexisting generations. The first section will be reserved for some conceptual clarifications on the concept of justice, on the distinction between age groups and birth cohorts, and on the specificity of age as a category for apportioning benefits and resources. Then, I will take up the issue of what is the analytical unit of justice across overlapping generations: age groups or birth cohorts. I shall try to disentangle the alternative between age groups and birth cohorts, on the one hand, and that between age groups at a snapshot and the whole life view, on the other. After a discussion of the latter alternative, it will become clear that also the whole life view will allow only a simultaneous comparison of age groups at a definite moment of time, though in the context of a distributive theory considering the whole life and its different phases. At the end, the age groups turn out to be the units of justice between overlapping generations in all three dimensions of justice. But while age groups are specifically appropriate for relational and political justice, in the case of distributive fairness, the comparison between simultaneous segments of different age groups should be assessed in the context of a distributive theory justifying the differential distributions at different ages. Any such theory refers to the temporality of human life, with different needs and capabilities at different stages of human life. I shall finally illustrate my age‐sufficiency principle that I deem appropriate for distributive comparisons between simultaneous age segments considered as different age stages of human life.