Journal article: We examine utilitarian criteria for evaluating profiles of well-being among infinitely many individuals. Motivated by the non-existence of a natural 1-to-1 correspondence between people when alternatives have different population structures, with a different number of people in each generation, we impose equal treatment in the form of Strong Anonymity. We demonstrate how a novel criterion, Strongly Anonymous Utilitarianism, can be applied in the Ramsey model, leading to an efficient and sustainable stream. We show how the criterion is the result of combining Strong Anonymity with other regularity axioms (Monotonicity, Finite Completeness, and continuity axioms) as well as axioms of equity, population ethics, sensitivity, and separability. We relate it to other strongly anonymous utilitarian criteria.