Evaluations of inifinite utility streams: Pareto efficient and egalitarian axiomatics

[EN]This investigation focuses on the aggregation of infinite utility streams by social welfare functions. We analyze the possibility of combining Pareto-efficiency and Hammond Equity principles when the feasible utilities for each generation are [0, 1] and the natural numbers. In the latter case, the Hammond Equity ethics can be combined with non-trivial specifications of the Pareto postulate, even through anonymous social welfare functions. As a consequence, any evaluation of infinite utility streams that verifies a mild specification of the Paretian axiom must exert some interference on the affairs of particular generations