This paper illustrates the application of functional-equations results in population ethics.In an intertemporal framework, we provide characterizations of several classes of variablepopulationsocial orderings that may depend on individual lengths of life in addition tolifetime utilities...

We analyze the rationalizability of variable-population social-choice functions in a welfaristframework. It is shown that xed-population rationalizability and a weakening ofcongruence together are necessary and suffcient for rational choice, given a plausible dominanceproperty that prevents the...